Field research 2003

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Introduction
The flexibility to plant crops of choice rather than to plant to maintain base acres of a farm program crop encourages crop rotations. Soybean acres continue to increase in Kansas. Soybean tolerance to a wide range in planting dates has helped the widespread acceptance of this crop. Nevertheless, most crops have an optimum planting date that can differ by both region and cultivar. Little current information is available in Kansas concerning soybean planting dates with modern cultivars. The objective of this study is to determine the optimum planting date for soybeans from a wide range of maturities over several environments in Kansas. Six similar studies were located across eastern Kansas in 1999 with 3 western Kansas sites added in 2000. This project is supported by the Kansas Soybean Commission with check-off funds.

Results
Planting dates varied from the desired dates from year to year because of weather conditions. Because of weather conditions and other factors, the study was not completed in 1999. In 2000, fairly poor stands were obtained with the 4 th date of planting because of dry soil conditions and these results are not reported. The first frost in the fall hastened the maturity of the fourth planting of the mid-IV soybeans even in 2001, when it was later than usual. Maturity was delayed by 20 days (2-yr. average) from the first planting date to the fourth planting date (planted 57 days later, 2-yr. average). There was an average difference of 20 3 days in maturity between the group II and mid group IV soybeans. A positive interaction of planting date x variety was observed. The fourth planting date delayed the maturity of the Grp. II soybeans more than the other varieties. The maturity of the mid-IV variety was affected less by delaying the planting date than the other varieties.
Soybean plants were shortest when planted early or late. The second and third planting dates were the tallest and similar in height. The grp. II soybeans were shortest and the grp. IV soybeans were tallest, with the mid-and late-III soybeans being intermediate and fairly similar in height.
Shattering had occurred with the Grp. II soybean in the first 2 planting dates (esp. the first planting date) before the plots could be harvested. In 2000, yields of the two earlier planting dates were higher than the third planting date (fourth date of planting was not harvested). This was attributed to the dry weather during the latter part of the growing season. In 2001, when rainfall was received in July and early August, the fuller season soybeans had a yield advantage in the first 3 dates of planting, while the group III soybeans had a slight yield advantage over the other 2 varieties with the 4 th date of planting. In 2002, the group II soybean had lower yields at all planting dates which was attributed to a somewhat poor stand obtained with low germination seed. Very little difference was observed between the other 3 varieties in this extremely dry year. Yields were slightly better with the second date of planting followed closely by the third date of planting. The fourth date of planting resulted in the lowest yield, mainly because no late season rainfall was received.
For the years this study was conducted, a planting date from about May 1 to about the middle of June was the best. Earlier planting did not decrease yields as much as later planting. 4 Table 2. Effects of planting dates and maturity groups on soybean maturity, Powhattan, 1999

Introduction
This study was conducted on an irrigated field at the Kansas River Valley Experiment Field, Rossville Unit, and on a dryland field at the Cornbelt Experiment Field near Powhattan. The objective was to evaluate the effect of nitrogen (N) and phosphorus (P) application, ratios, and placement on plant uptake and yield of soybeans.

Procedures
The study was conducted for two years on two sites: (1) Cornbelt Experiment Field near Powhattan, on a dryland Grundy silty clay loam site previously cropped to soybeans with a pH of 6.4, an organic matter content of 3.2 percent, and a P test level of 12 ppm and (2) Kansas River Valley Experiment Field, Rossville Unit, on an irrigated Eudora silt loam site previously cropped to corn with a pH of 6.4, an organic matter content of 1.6 percent, and a P test level of 21 ppm.
The treatments were applied and the plots were planted at 144,000 seeds/a in 30-inch rows May 16, 2001and June 3, 2002at Rossville and May 23, 2001and May 31, 2002 Powhattan. Soybean varieties used were Stine 4200-2 (2001) and Pioneer Brand 93B85 (2002) at Rossville and Taylor 394RR (2001) and Taylor 380RR (2002) at Powhattan. The Rossville site was sprinkler irrigated as needed. The plots were harvested using a plot combine.

Introduction
Chemical weed control and cultivation have been used to reduce weed competition in row crops for many years. This test included 16 herbicide treatments and an untreated control.

Procedures
This test was conducted on a Grundy silty clay loam soil previously cropped to soybeans with a pH of 6.5 and an organic matter content of 3.1 percent. Pioneer Brand 84G62 grain sorghum hybrid was planted May 31 at 65,000 seeds/a in 30-inch rows. Anhydrous ammonia at 90 lbs N/a was applied preplant. Herbicides were applied preemergent (PRE) -June 1 and postemergent (EP) -June 25. The plots were not cultivated. The data reported here are for crop injury ratings made on July 15 -20 days after EP applications; and weed control ratings made on July 31 -36 days after EP applications. The growing season was very dry and weed pressure was light and variable. Weeds rated were common cocklebur (cocb), jimsonweed (jiwe), and ground cherry (grch). Plots were harvested on October 14 using a modified John Deere 3300 plot combine.

Results
Because of the dry weather, weed pressure was light and variable. Crop injury was observed with treatments containing Aim, but by 3 weeks after treatment, the amount of injury had decreased and had no significant effect on grain yield ( Table 2). Some of the treatments had weed control ratings that would be considered unsatisfactory, but few of the differences in ratings were statistically significant because of the variability of weed pressure in the test area.

EAST CENTRAL KANSAS EXPERIMENT FIELD Introduction
The research program at the East Central Kansas Experiment Field is designed to enhance the area's agronomic agriculture. Specific objectives are: (1) to identify the top performing varieties and hybrids of wheat, corn, grain sorghum, and soybean; (2) to determine the amount of tillage necessary for optimum crop production; (3) to evaluate weed control practices using chemical, non-chemical, and combination methods; and (4) to test fertilizer rates and application methods for crop efficiency and environmental effects.

Soil Description
Soils on the Field's 160 acres are Woodson. The terrain is upland, level to gently rolling. The surface soil is a dark, gray-brown, somewhat poorly drained, silt loam to silty clay loam with a slowly permeable, clay subsoil. The soil is derived from old alluvium. Water intake is slow, averaging less than 0.1 in. per hour when saturated. This makes the soil susceptible to runoff and sheet erosion.

Weather Information
Precipitation during 2002 totaled 27.31 in., which was 9.58 in. below the 34-yr average ( Table 1). Most of the moisture deficit occurred during the mid to late parts of the growing season. Rainfall during April and May was 2.88 in. above normal. June, July, August, and September rainfall was 9.95 in. below normal.
The coldest temperatures during 2002 occurred the first week of January with three days in single digits and one day with 1 o F below zero. Cold temperatures returned during late February-early March with 4 days in single digits and one day with 1 o F below zero . The overall coldest temperatures recorded were 1 o F below zero on January 3 and March 4. There were 55 days during the summer in which temperatures exceeded 90 degrees. The two hottest days were July 9 and 26, when daily temperatures reached 100 o F.
The last freeze in the spring was April 5 (average, April 18) and the first killing frost in the fall was October 14 (average, October 21). The number of frost-free days was 191 compared with the long-term average of 185 days.

Introduction
Crop residues are increasingly becoming a source of raw materials for various nonagricultural uses. In Kansas, two companies are currently manufacturing wheatboard from wheat straw. In Iowa, over 50,000 tons of corn residue was harvested during the 1997-1998 crop year for ethanol production. In Minnesota, a company is planning to introduce a BIOFIBER soy-based particle board. Other companies will likely soon join the market for production of other bioproducts (paper). All of this is in addition to the customary on-farm use of crop residues for livestock feed and bedding. These new uses are welcomed new sources of revenue for crop producers. However, crop producers must be aware that crop residues also are needed for soil erosion protection and to replenish organic matter in the soil. Crop residues are the single most important source of carbon replenishment in soils.
Unfortunately, data on the effects of crop residue harvesting on soil properties and crop yield are very limited, especially for long-term, continuous harvesting of crop residues. From past history we know that grain producers have harvested crop residues for livestock feed for years with little noticeable side effect. However, harvesting crop residues for farm use has generally not been on a continuous basis from the same field. Also, some of the crop residues harvested may be returned as animal wastes. With non-agricultural uses, this generally would not be the situation, and there would be increased probability for repeat harvests. Harvesting crop residues continually would remove larger amounts of plant nutrients and return less organic plant material to the soil. The effects of fertilizer management in offsetting these losses are not well understood.
This study was established to determine the effects of long-term annual harvesting of crop residues and the additions of varying levels of crop residues on crop yields and soil properties in a soybean -wheat -grain sorghum/corn rotation, fertilized with variable rates of nitrogen (N), phosphorus (P) and potassium (K).

Procedures
This study was established in the fall of 1980 on a Woodson silt loam soil (fine montmorillonitic, thermic, Abruptic Argiaquolls) at the East Central Experiment Field. The residue treatments evaluated were: (1) crop residue harvested annually, (2) normal crop residue incorporated, and (3) twice (2X) normal crop residue incorporated (accomplished by adding and 13 spreading evenly the crop residue from the residue harvest plots). Superimposed over the residue treatments were four levels of fertilizer treatments; zero, low, normal, and high levels of N-P-K fertilizer at rates for each crop (Table 2). Crops planted were soybean, wheat, and grain sorghum/corn in a 3-year rotation. Crop grain and residue yields were measured each year and soil samples (0 to 2-in. depth) were collected and analyzed after year 21 to detect any changes in soil properties.

Results
Grain yields and residue yields for the last 10 years of this 22-year study are summarized in Tables 3 and 4. The residue treatments have not caused differences in either grain or residue yields for any crop in any year since the study was initiated, except for 1987. In 1987, a year when there was hail damage, less residue was measured in the 2X normal residue incorporated treatment than with normal residue incorporated. This may have been the result of uneven hail damage rather than an effect of the residue treatments. Summed over all 22 years, 1980-2002, total grain and residue yields for residue harvesting and 2X normal residue incorporated treatments differ from normal residue incorporated by less than 1.5 percent.
In contrast, the fertilizer treatments have produced significant grain and residue yield differences, averaging 36% and 37%, respectively, for all years. Highest grain and residue yields have been produced with the normal and high fertilizer treatments and the lowest grain and residue yields with the zero and low fertilizer treatments.
Although there has been little effect on grain and residue yields with crop residue harvesting, soil properties have changed. The effects of the residue and fertilizer treatments on soil properties are shown in Table 5. Soil organic matter and soil exchangeable K have decreased with annual harvesting of crop residue. The harvesting of crop residue has lowered soil exchangeable K by nearly 12%. This is because of the high K content in crop residue and removing it removes large amounts of K. Crop residue harvesting decreased soil organic matter 10%. Doubling crop residue increased soil organic matter 11%. The fertilizer treatments produced the expected increases in P and K. Available P, exchangeable K, and organic matter all increased with increased fertilizer application. Soil pH decreased with increased fertilizer application.
These data suggest that harvesting of crop residues from fields similar to this soil will have little effect on grain or residue yields over the short to moderate-term and should require no special changes in management practices, except possibly to keep a close watch on soil K test levels. However, in the long term, repeated harvesting of crop residues from the same field could eventually cause problems. This is because very long-term harvesting of crop residues could cause further decreases in soil organic matter to a point where crop yields will be affected. The effects of crop residue harvesting develop slowly and could take many years before reaching equilibrium. With different soils and different environments, the time period for yield limitations to occur could be much different. This soil was initially quite high in soil organic matter and had initially high levels of soil fertility. Soils with lower organic matter and lower fertility may be affected more rapidly by crop residue harvesting. 14 Table 2. Nitrogen, phosphorus, and potassium fertilizer treatments for crops in rotation, East Central Experiment Field, Ottawa, KS.

Introduction
Water quality is an issue that concerns everyone. Total Maximum Daily Loads (TMDLs) are being implemented in Kansas for various contaminants in streams and water bodies. Contaminants of most concern are sediment, nutrients, pesticides, and fecal coliform bacteria. In watersheds with waters not meeting standards, farmers and other land owners will be requested, on a voluntary basis, to reduce contaminant loading by implementing Best Management Practices (BMPs).
Numerous BMPs are available to crop producers to reduce soil erosion and sediment in runoff from cropland. However, no-till has been shown to be one of the most effective BMPs because it targets sediment control at the origination point. Tillage/planting systems such as no-till, however, provide little opportunity for incorporating fertilizer, manure, and herbicides. When surface applied, an increased percentage of these crop inputs contact runoff waters and that results in increased contaminant losses.
Consequently, to attain balanced water quality control, a comprehensive management strategy beyond just no-till is needed. A system of farming is needed that uses combinations of best management practices (BMPs) so that all runoff contaminants are controlled. We refer to such a strategy as "Integrated Agricultural Management Systems." The purpose of this study was to test, in a fieldsize setting, effects of different combinations of tillage, fertilizer, and herbicide management practices for balanced water quality protection.

Procedures
The study location was on an approximately 10-acre, parallel-terraced field near Lane in southeast Franklin County, KS. Soils in the field were a mixture of Eram-Lebo with some Dennis-Bates complex (Argiudolls, Hapludolls and Paleudolls). Bray-1 P soil test initially was 13 ppm, which according to K-State recommendations is a low to medium P soil test.
Three combinations of tillage, fertilizer, and herbicide management practices were evaluated starting in 1998. The combinations were: (1) No-till, with fertilizer and herbicides broadcast on the soil surface; (2) No-till, with fertilizer deep-banded (3-5 inch depth) and herbicides split broadcast on the soil surface; and (3) Chisel-disk-field cultivate with fertilizer and herbicides incorporated by tillage. All treatments were replicated twice and were established between terraces to facilitate runoff water collection. The crops grown were grain sorghum and soybean in alternate years in rotation. The rate of fertilizer applied for grain sorghum was 70 lb N, 33 lb P 2 O 5 , and 11 lb K 2 O per acre. No fertilizer was applied for soybean. Atrazine ( 1.5 lb/a ai) and Dual (metolachlor 1.25 lb/a ai) herbicides were applied for weed control in grain sorghum. For soybean, Roundup Ultra (glyphostate 1 lb/a ai) and metolachlor (1.25 lb/a ai) herbicides were applied.
Rainfall amounts were recorded and runoff was collected by instrumentation of all treatment areas between terraces with weirs and automated ISCO samplers. The runoff water collected was analyzed for sediment, nutrients, and herbicide concentrations. Mass losses of contaminants in the runoff were calculated by multiplying the runoff concentrations times runoff volumes

Rainfall and Runoff
Averaged across all runoff sampling dates and years (1998)(1999)(2000)(2001)(2002), rainwater that ran off was 3.81 inches or 40% in the no-till system and 2.26 inches or 24% in the chisel-disk-field cultivate system ( Figure 1). Part of the reason that runoff was greater in no-till than in the chisel-disk field cultivate system was that no-till conserves surface soil moisture which then generates runoff more quickly. Also, each time the soil in the chisel-disk field cultivate system was tilled it loosened and dried the soil, which then increased the soil's capacity to absorb rainwater.

Soil Erosion and Sediment Losses
Even though runoff was less in the chiseldisk field cultivate system, the amount of soil loss was three times greater compared to no-till ( Figure 2). With the chisel-disk field cultivate system the 5-yr average soil loss was 0.80 ton/a per growing season and with no-till 0.26 ton/a.

Nutrient and Herbicide Losses
Total P concentrations and losses in the runoff generally paralleled soil losses ( Figure  3). This is because sediment P in runoff accounts generally for most total P losses. Soluble P and atrazine losses in the runoff water were highest with surface P fertilizer and herbicide applications in no-till (Figures 4 and 5). Incorporation of P fertilizer and atrazine with tillage decreased losses. Deep-banding fertilizer P in no-till also reduced soluble P losses. Concentrations of soluble P and atrazine in runoff were highest generally during the first couple of runoff events after application (data not shown). This is because that is when the largest portion of these materials are still present on the soil surface and have not yet been absorbed into the soil.

Conclusions
These data confirm that no-till is one of the most effective BMPs for reducing soil erosion and sediment in runoff from crop land. However, if fertilizer and herbicides are surface applied losses of these crop inputs may be increased compared to when incorporated by tillage. Therefore, to assure balanced runoff water protection, it will be important to subsurface apply P fertilizer when planting crops no-till. This could be in the form of preplant deep banding (3-5 inch coulter knife depth on 15 in. centers, which was used here), 2x2 inch band placement of fertilizer with the planter, or some combination of these. Steps to reduce herbicide losses when planting crops notill will also be needed. This might be accomplished partially by timing of the herbicide applications when there is less opportunity for runoff-producing rains (fall or early spring, or as post emergence applications compared to planting-time applications).

Introduction
Bermudagrass can be a high-producing, warm-season, perennial forage for eastern Kansas when not affected by winterkill. Producers in southeastern Kansas have profited from the use of more winter-hardy varieties that produced more than common bermudas. Further developments in bermudagrass breeding should be monitored to speed adoption of improved, cold-hardy types.

Procedures
Plots were sprigged at 1-ft intervals with plants in peat pots on April 27, 2000 at the East Central Experiment Field, Ottawa, except for entry CD 90160 that was seeded at 8 lb/acre of pure, live seed. Plots were 10 x 20 ft each, in four randomized complete blocks. Plots were subsequently sprayed with 1.4 lb/a of Smetolachlor. Plot coverage was assessed in August 2000, and in May and July 2001 and July 2002. Application of 60 lb/a of N was made in April 2002. Strips 20 x 3 ft were cut on July 3, 2002. Subsamples were collected for determination of moisture.

Results
The spring and early summer of 2002 was favorable for growth. However, regrowth was curtailed after the July 3 harvest because of drought. Soil moisture was not adequate for growth until bermudagrass was nearing fall dormancy.
Plot coverage was not very dense in July 2002 for any of the entries, so ratings were judged on a scale of 1 to 3, with 1 being poor, 2 being fair to good, and 3 being excellent (Table 6). Besides CD 90160, which was being reestablished from sprigs, Ozarka and the original Midland had the poorest plot coverage.
Forage yields in July 2002 were higher (P<.05) for the two experimental lines, LCB 84x19-16 and LCB 84x16-66, than for the other entries (Table 7). Midland yielded less than the seven other entries that were harvested.
Total yields for the two years were higher for the two experimental cultivars than for four other entries (Table 7). Midland again produced less forage than the seven other entries that were harvested. The two surviving seed-producing types, Guymon and Wrangler, produced less than the four highest yielding entries, averaging 86% of the average yield of the sprigged types. 20

Introduction
Soybean producers in east-central Kansas have a wide window in which they can plant soybean (late April through the middle of July) and a wide range of maturity groups they can plant (II, III, IV, and V). Very early planting of soybean runs the risk of poor stand development and injury by a killing late spring freeze. However, they tend to maximize maturity group differences and yield potential if all other factors are not limiting. Delayed or very late planting dates reduce vegetative growth before flowering, reduce the effects of maturity groups, reduce yield potential, and run the risk of a fall freeze killing the crop before maturity. Other factors associated with planting dates and maturity groups also can affect yield, such as differences in soil and air temperatures that occur with different planting dates, differences in disease and weed pressures, and most importantly, differences in moisture availability during the critical grain fill period. However, selection of soybean maturity groups and time of planting can be helpful to manage situations resulting in planting delays, or to try and match the grain fill period with the most favorable seasonal moisture pattern, spread the harvest load, or shorten time to maturity in order to plant another crop more quickly.
This study evaluates effects on soybean yield under east-central Kansas conditions from five soybean variety/maturity groups planted at various planting dates.

Procedures
This experiment was conducted at the East Central Experiment Field near Ottawa on a Woodson soil. The variety/maturity groups planted were IA2021 (II), IA3010 (early III), Macon (late III), KS4694 (IV) and Hutcheson (V). Planting ranged from April 28 through July 24. Seeding rate was 175,000 seeds/a. Planting was with a drill in 7-in. rows. Weeds were controlled with 2 pt/a Treflan and 6.8 oz/a Canopy XL herbicide and hand weeding. At maturity, the center nine rows of each 11-row plot were harvested for yield.

Introduction
Research at the Harvey County Experiment Field deals with many aspects of dryland crop production on soils of the Central Loess Plains and Central Outwash Plains of central and south central Kansas, and is designed to directly benefit the agricultural industry of the area. The focus is primarily on wheat, grain sorghum, and soybean, but research is also conducted on alternative crops such as corn and sunflower. Investigations include variety and hybrid performance tests, chemical weed control, tillage methods, cropping systems, fertilizer use, and planting practices, as well as disease and insect resistance and control.

Soil Description
The Harvey County Experiment Field consists of two tracts. The headquarters tract, 75 acres immediately west of Hesston on Hickory St., is all Ladysmith silty clay loam with 0-1% slope. The second tract, located 4 miles south and 2 miles west of Hesston, is comprised of 142 acres of Ladysmith, Smolan, Detroit, and Irwin silty clay loams, as well as Geary and Smolan silt loams. All have 0-3% slope. Soils on the two tracts are representative of much of Harvey, Marion, McPherson, Dickinson, and Rice Counties, as well as adjacent areas. These are deep, moderately well to well-drained, upland soils with high fertility and good water-holding capacity. Water run-offis slow to moderate. Permeability of the Ladysmith, Smolan, Detroit, and Irwin series is slow to very slow, whereas permeability of the Geary series is moderate.

2001-2002 Weather Information
Extremely heavy rains fell on exceedingly dry soil about 2 weeks before wheat planting began. Seedbed conditions were good, but lacked consistent moisture at seed depth. However, timely rains in early October insured prompt and complete wheat emergence. After a cool October, temperatures remained well above average during November and December. Fall wheat development was good despite very limited precipitation. Winter precipitation was above normal in January, but below normal during the other winter months. Mean temperatures continued to be well above normal in January, near normal in February, and colder than usual in March. Wheat stands were good, with excellent winter survival. Foliage greened-up again in mid-March after getting burned by zero-degree temperature near the beginning of the month.
Rainfall was somewhat above normal in April, but nearly 2 inches below normal in May. Fortunately, May temperatures also were cooler than usual. June rains were excessive during the last 2 weeks before wheat harvest. Low levels of barley yellow dwarf symptoms were observed. Leaf rust appeared in late May but had little impact on wheat yield.
Soil moisture was generally favorable for row crop planting. However, early-June plantings in some cases were affected by soil crusting following copious rainfall prior to emergence. Mean air temperatures were near normal for that month. Crazy top downy mildew in grain sorghum was evident in certain areas affected by the excessive rainfall. Scattered affected plants remained stunted and did not produce grain. Average maximum air temperatures were below normal in July and August. During this time, temperatures only equaled or exceeded 100 o F on 7 days. However, rainfall was below normal, and drouth stress occurred during these months. Temperatures were above normal and precipitation well below normal in September.
Corn had no significant diseases, but did encounter limited grasshopper activity. In some locations, chinch bugs became a significant threat to grain sorghum by mid-season and required remedial treatment. Stalk rot in certain sorghum hybrids was associated with drouth stress, and resulted in late-season lodging. Bean filling in soybean was curtailed prematurely by drouth stress. While summer drouth affected the performance of all the row crops, limited, but timely rains averted even more deleterious effects on yields.
Freezing temperatures occurred last in the spring on April 5. First killing temperatures occurred next on October 13. The frost-free season of 191 days was about 23 days longer than normal.

Summary
Tillage system effects on continuous wheat, continuous grain sorghum, and annual rotations of wheat with row crops were investigated for a sixth consecutive year. In most seasons, tillage in alternate years did not consistently affect no-till wheat after row crops. However, in 2002, prior tillage for row crop resulted in a 6.6 bu/a increase in yield of no-till wheat after sorghum and soybean, but not after corn. In contrast with most years, crop rotation effects on wheat yield were not significant. Tillage systems did not meaningfully affect yields of row crops in rotation with wheat except for corn, which responded to no-till with a 2.7 bu/a increase. Wheat rotation increased sorghum yields by 6.6 bu/a in comparison with continuous sorghum. Tillage systems did not significantly affect continuous sorghum nor its response to planting date. Yields from June continuous sorghum plantings exceeded those of May plantings by 23.3 bu/a; however, 6-year average yields continued to favor May planting by 5.6 bu/a.

Introduction
Crop rotations facilitate reduced-tillage practices, while enhancing control of diseases and weeds. Long-term research at Hesston has shown that winter wheat and grain sorghum can be grown successfully in an annual rotation. Although subject to greater impact from drouth stress than grain sorghum, corn and soybean also are viable candidates for crop rotations in central Kansas dryland systems that conserve soil moisture. Because of their ability to germinate and grow under cooler conditions, corn and soybean can be planted earlier in the spring and harvested earlier in the fall than sorghum, thereby providing opportunity for soil moisture replenishment as well as a wider window of time within which to plant the succeeding wheat crop. This study was initiated at Hesston on Ladysmith silty clay loam to evaluate the consistency of corn and soybean production versus grain sorghum in an annual rotation with winter wheat and to compare these rotations with monoculture wheat and grain sorghum systems.

Procedures
Three tillage systems were maintained for continuous wheat; two for each row crop (corn, soybean, and grain sorghum) in annual rotation with wheat; and two for continuous grain sorghum. Each system, except no-till, included secondary tillage as needed for weed control and seedbed preparation. Wheat in rotations was planted after each row-crop harvest without prior tillage. The following procedures were used. Continuous wheat no-till plots were sprayed with Roundup Ultra + 2,4-D A + Banvel + Placement Propak (1.5 pt + 1 pt + 4 oz /a + 1% v/v) on July 11. Additional fallow applications of Roundup Ultra + Placement Propak at 1.5 pt/a + 1% and Roundup Ultra + ammonium sulfate at 20 oz + 2.6 lb/a were made on September 6 and October 3, respectively. Variety 2137 was planted October 8 in 8-inch rows at 90 lb/a with a CrustBuster no-till drill equipped with double disk openers. Wheat was fertilized with 71 lb N/a and 35 lb P 2 O 5 /a as preplant, broadcast ammonium nitrate and infurrow diammonium phosphate at planting. An additional 50 lb/a of N was broadcast on January 28. WW-NT and WW-C plots were sprayed for cheat control with Maverick 75 DF at 0.66 oz/a + 0.5% nonionic surfactant (NIS) on November 16. WC-NTNT and WG-NTNT were sprayed on the same day for cheat control with Everest 70 1 DF at 0.6 oz/a + 0.5% NIS. No herbicides were used on wheat in the remaining tillage and cropping systems. Wheat was harvested on June 26, 2002. No-till corn after wheat plots received the same herbicide treatments as WW-NT during the summer plus a mid-November application of AAtrex 90 DF + 2,4-D LVE + crop oil concentrate (COC) at 1.67 lb + 1 pt + 1 qt/a. Preplant weed control was achieved with Roundup Ultra + Banvel + Placement Propak (1 pt + 2 oz/a +1%). Weeds were controlled during the fallow period in CW-V plots with a combination of two tillage operations and two herbicide applications targeting field bindweed. An additional tillage operation was necessary for seedbed preparation. Corn was fertilized with 111 lb/a N as ammonium nitrate broadcast prior to planting. An additional 14 lb/a N and 37 lb/a P 2 O 5 were banded 2 inches from the row at planting. A White no-till planter with doubledisk openers on 30-inch centers was used to plant Pioneer 35N05 at approximately 18,700 seeds/a on April 18, 2002. All corn plots were sprayed after planting with Dual II Magnum + AAtrex 4L (1.33 pt + 1.5 pt/a) for preemergence weed control. Row cultivation was not used. Corn was harvested on August 29.
No-till sorghum after wheat plots received the same fallow and preplant herbicide treatments as no-till corn. Continuous NT sorghum plots were treated with AAtrex 90 DF + 2,4-D LVE + Banvel + COC (1.67 lb + 1 pt + 4 oz + 1 qt/a) in mid-November. GG-NT May areas received a preplant application of Roundup Ultra + Banvel + Placement Propak (1 pt + 2 oz/a + 1%). GG-NT June plots were treated with Roundup Ultra + Placement Propak (1 qt/a + 1%) before planting. GW-V plots were managed like CW-V areas during the fallow period between wheat harvest and planting. However, sorghum required one more tillage operation than corn because of later planting. Between crops, all GG-C plots were tilled once in the fall (chisel) and twice in the spring (mulch treader and sweep-treader). Sorghum was fertilized like corn, but with 116 lb/a total N. Pioneer 8500 treated with Concep III safener and Gaucho insecticide was planted at 42,000 seeds/a in 30inch rows on May 6, 2002. A second set of continuous sorghum plots was planted on June 22. Post-plant preemergence herbicides for sorghum in rotation with wheat consisted of Dual II Magnum at 1.67 pt/a (GW-NT) or Dual II Magnum at 1.33 pt/a + AAtrex 4L at 1.5 pt/a (GW-V). Continuous sorghum was treated with Dual II Magnum + AAtrex 4L at 1.33 pt + 1.5 pt/a (GG-NT May) or at 1.33 pt + 1 qt/a (GG-C May , GG-NT June , GG-C June ) shortly after planting. Sorghum was not row cultivated. May-and June-planted sorghum were harvested on September 6 and November 21, respectively.
Fallow weed control procedures for no-till soybean after wheat were the same as for CW-NT and GW-NT, except that there was no late fall herbicide application for residual weed control. Roundup Ultra + Banvel + Placement Propak (1 pt + 2 oz/a + 1%) controlled emerged weeds just prior to planting. SW-V tillage and herbicide treatments were the same as those indicated for GW-V. After planting, weeds were controlled with preemergence Dual II Magnum + Scepter 70 DG (1.33 pt + 2.8 oz/a). Iowa 3010 soybean was planted at 7 seeds/ft in 30-inch rows on May 6 and harvested on September 25, 2002.

Wheat
An extreme rainfall event near mid-September helped alleviate extremely dry conditions. At planting time, surface soil moisture was generally adequate for wheat germination and emergence.
Fall wheat development was acceptable despite very little additional rainfall. Total precipitation for the period from planting until the end of May was 7.9 inches below normal. However, favorable temperatures at important stages of wheat development resulted in very good yields.
Crop residue cover in wheat after corn, sorghum, and soybean averaged 72, 72, and 36%, respectively (Table 2). WW-B, WW-C, and WW-NT averaged 8, 35, and 71% residue cover after planting, respectively. Wheat stands averaged 99% complete and were not affected by tillage or cropping system. Cheat control was excellent. Plant N concentration in wheat at late boot-early heading stage was highest in continuous cropping (2.10%) and in rotations with sorghum (2.02%) or corn (1.93%), but slightly lower following soybean (1.80%). Tillage system did not significantly affect wheat plant N level. Wheat heading date tended to be slightly delayed in continuous NT systems versus V-blade or Chisel systems with tillage in alternate years. Unlike previous years, crop rotation had no significant effect on wheat yields. Wheat in rotation with corn, sorghum, and soybean averaged 49.9, 51.8, and 52.3 bu/a, while continuous wheat yields averaged 52.4 bu/a. Tillage in the preceding year did not affect the yield of wheat after corn, but increased the production of NT wheat after sorghum and soybean by 6.6 bu/a. In continuous wheat, Burn and Chisel systems were, respectively, 12.2 and 7.2 bu/a superior to NT. Test weights were below average and were not significantly affected by tillage or cropping systems.

Row Crops
Corn, sorghum, and soybean following wheat had an average of 45, 40, and 33%, respectively, crop residue cover after planting in V-blade systems (Table 3). Where these rowcrops were planted NT after wheat, crop residue cover averaged 78%, with little difference among rotations.
The chisel system in continuous sorghum resulted in ground cover comparable to the V-blade system in sorghum after wheat. However, NT sorghum after wheat averaged 12 and 17% more ground cover than May-and June-planted NT continuous sorghum. Drouth stress caused low yields in all row crops. Tillage systems had no significant effect on row crop stands, maturity, number of ears or heads/plant, or grain test weight. Corn yields averaged 46.3 bu/a. NT increased corn yield by 2.7 bu/a in comparison with the V-blade tillage system. Sorghum and soybean averaged 60.7 and 19.7 bu/a, with no apparent tillage effect. Wheat rotation benefitted May-planted sorghum, increasing flag leaf N by 14%, number of heads/plant by 39%, and grain yield by 13%.
Planting date effect on yield of continuous sorghum was highly significant because of the seasonal weather pattern. June planting shortened the period from planting to half bloom by 19 days, increased the number of heads/plant by 22%, increased leaf N by 7%, and increased yield significantly. Sorghum planted after mid-June produced 74.1 bu/a, 46% more than sorghum planted in early May. However, long-term average yields continued to show an advantage of 5.6 bu/a for May vs June planting.  Multiple -year averages: 1997-1999, 2001-2002 for corn and 1997-2002 for sorghum and soybean. 3 Maturity expressed as follows: corn -days from planting to 50% silking; grain sorghum -number of days from planting to half bloom; soybean -number of days from planting to occurrence of 95% mature pod color. 4 Corn leaf above upper ear at late silking; sorghum flag leaf at late boot to early heading. 5 LSD's for comparisons among means for continuous sorghum and sorghum after wheat treatments.

Summary
Late-maturing Roundup Ready® soybean drilled in wheat stubble at 135,000, 165,000, and 200,000 seeds/a produced an average of 2.25 ton/a of above-ground dry matter and a N yield of 87 lb/a potentially available to the succeeding crop. Soybean cover crop did not affect grain sorghum yield the following growing season, but, when averaged over N rate, resulted in a 0.15% N increase in flag leaves. N fertilizer significantly affected sorghum maturity, heads/plant, leaf N concentration, yield, and bushel weight. Highest overall average yield of 103 bu/a occurred with 60 lb/a of N. Additional N fertilizer did not significantly increase leaf N or bushel weight.

Introduction
Research at the KSU Harvey County Experiment Field over the past 8 years has explored the use of hairy vetch as a winter cover crop following wheat in a winter wheat-sorghum rotation. Results of long-term experiments showed that between September and May, hairy vetch can produce a large amount of dry matter with an N content on the order of 100 lb/a. However, significant disadvantages also exist in the use of hairy vetch as a cover crop. These include the cost and availability of seed; interference with the control of volunteer wheat and winter annual weeds; and the possibility of hairy vetch becoming a weed in wheat after sorghum.
New interest in cover crops has been generated by research in other areas showing the positive effect these crops can have on the overall productivity of no-till systems. In Ohio, use of a late-maturing Roundup Ready soybean has shown promise as a summer cover crop in a rotation from wheat to corn. The current experiment was conducted as a pilot project to assess soybean seeding rate and N rate effects on no-till grain sorghum after wheat.

Procedures
The experiment site was located on a Smolan silt loam soil. Following winter wheat harvest, weeds were controlled with Roundup Ultra + Banvel + Placement Propak (1 qt/a + 2 oz/a + 1% v/v) in early July. Asgrow 6701 RR soybean was no-till drilled in 8-inch rows in randomized strips with four replications at 0, 135,000, 165,000, and 200,000 seeds/a on July 11, 2001. Unreplicated soybean plants from 1-m 2 samples were harvested at the first killing frost on October 16. Wholeplant soybean dry matter yield estimates were obtained and subsamples analyzed for N content. Volunteer wheat was controlled in the fall with Roundup herbicide.
Soybean plants in existing wheat stubble were left undisturbed after maturity. Preplant weed control was accomplished with the application of Roundup Ultra + AAtrex 4L + Dual II Magnum + 2,4-D LV6 + Banvel (1.6 pt/a +1.5 pt/a + 1.33 pt/a + 1.33 oz/a + 2 oz/a) on May 20, 2002. Randomized N rates of 0, 30, 60, and 90 lb/a were broadcast as ammonium nitrate on May 31. Pioneer 8505 grain sorghum with Concep III and Gaucho seed treatments was no-till planted at 42,000 seeds/a in 30-inch rows on June 3, 2002. Sorghum was harvested on September 24.

Results
Soybean stand establishment and crop development were good. Ground cover and volunteer wheat control varied with soybean seeding rate. Although volunteer wheat was suppressed by the soybean cover crop, some wheat growth occurred. Fall application of Roundup herbicide was necessary. Despite the choice of a late maturing soybean, some pod set and minor seed development was noted. At termination by frost on October 16, soybean whole-plant above-ground dry matter yield estimates were 2.3, 2.5, and 2.0 tons/a with seeding rates of 135,000, 265,000 and 200,000/a, respectively. Nitrogen concentrations in soybean plant samples ranged from 1.88% to 2%, with an average of 1.92%. Corresponding N yields of soybeans at these seeding rates were calculated to be 85, 100, and 75 lb/a. Soybean cover crop increased grain sorghum leaf N concentration, but had no effect on yield nor any of the other variables measured (Table 4). This increase averaged 0.15% N across N rates, and there were no significant differences among soybean seeding rates of 135,000 to 200,000. Nitrogen fertilizer significantly decreased the number of days to half bloom as well as increased the number of sorghum heads/plant, sorghum leaf N concentration, yield, and bushel wt. Highest grain yield occurred with 60 lb/a of N fertilizer. Leaf N and grain test weight also did not increase significantly with additional N fertilizer.

Summary
Wheat production was evaluated in the third cycle of annual wheat-sorghum and wheat-vetchsorghum rotations. Treatment variables included disk and herbicide termination methods for hairy vetch and N fertilizer rates of 0 to 90 lb/a. Fertilizer N and hairy vetch raised wheat plant N levels. Without vetch in the rotation, wheat plant N increased only at 90 lb/a. Averaged over N rate, hairy vetch resulted in respective increases of 0.17% N to 0.33% N in disk and no-till systems. Nitrogen rate significantly increased wheat yield, but the residual benefit of the cover crop on wheat grain production was less apparent than in previous years. With vetch/disk, wheat produced 5.7 bu/a more than with vetch/no-till. But, at 0 lb/a of fertilizer N as well as at the average N rate, yields of wheat in hairy vetch systems were not significantly greater than in no-vetch. In wheat after sorghum without vetch, 30 and 60 lb/a of fertilizer N progressively increased yield. However, in wheat after vetch-sorghum, yields at these N rates did not differ significantly.

Introduction
Hairy vetch can be planted in September following wheat and used as a winter cover crop ahead of grain sorghum in an annual wheatsorghum rotation. Soil erosion protection and N contribution to the succeeding crop(s) are potential benefits of including hairy vetch in this cropping system. The amount of N contributed by hairy vetch to grain sorghum has been under investigation. The longer-term benefit of vetch in the rotation is also of interest. This experiment concluded the third cycle of a crop rotation in which the residual effects of vetch as well as N fertilizer rates were measured in terms of N uptake and yield of wheat.

Procedures
The experiment was established on a Geary silt loam soil with the initial planting of hairy vetch following winter wheat in the fall of 1996. Sorghum was grown in 1997 with or without the preceding cover crop and fertilized with N rates of 0, 30, 60, or 90 lb/a. Winter wheat was no-till planted in 8-inch rows into sorghum stubble in the fall of 1997. In the third cycle of the rotation, hairy vetch plots were seeded at 25 lb/a in 8-inch rows on October 4, 2000. One set of vetch plots was terminated by disking on May 9. Hairy vetch in a second set of plots was terminated at that time with Roundup Ultra + 2,4-D LVE + Banvel (1 qt + 1.5 pt/a + 0.25 pt/a). Weeds were controlled with tillage in plots without hairy vetch.
Vetch forage yield was determined by harvesting a 1-m 2 area from each plot on May 9, 2001.
Nitrogen fertilizer treatments were broadcast as ammonium nitrate on June 14. All plots received 35 lb/a of P 2 O 5 , which was banded as 0-46-0 at sorghum planting. Pioneer 8505 was planted in 30-inch rows at approximately 42,000 seeds/a on June 15, 2001. Weeds were controlled with a preemergence application of Lasso + AAtrex 4L (2.5 qt + 1 pt/a). Grain sorghum was combine harvested on October 11. Fertilizer N was broadcast as 34-0-0 on October 20, 2001, at rates equal to those applied to the prior sorghum crop. On the same day, variety 2137 winter wheat was no-till planted in 8-inch rows into sorghum stubble at 120 lb/a with 37 lb/a of P 2 O 5 fertilizer banded in the furrow. Wheat was harvested on June 26, 2002.

Results
Hairy vetch terminated near mid-May, 2001, produced an average of 1.42 ton/a of dry matter, yielding 103 lb/a of N potentially available to the sorghum that followed (Table 5). In the absence of fertilizer N, an increase of 0.16% N in sorghum leaves occurred in the vetch versus no-vetch cropping systems. This represented a N contribution equivalent to 19 lb/a of fertilizer N. Leaf N levels in sorghum after vetch were not significantly affected by method of vetch termination or N rate. While vetch termination method had no affect on sorghum yield, the average vetch contribution to sorghum yield was equivalent to 43 lb/a of fertilizer N.
Precipitation total for the period from November 1 through May 31 was nearly 5.5 inches below normal. The residual effect of hairy vetch on wheat in the rotation was evident, but it was not as pronounced as in previous years.
Vetch accounted for wheat plant height increases of 3 to 5 inches, but only with zero fertilizer N. Averaged across N rates, vetch treatments were associated with significantly higher wheat plant N levels. Increases ranged from 0.17% N to 0.33% N in disk and no-till systems. Plant N increases following vetch were most notable at 60 and 90 lb/a of fertilizer N. Vetch/disk system resulted in a yield 5.7 bu/a greater than with vetch/no-till. However, at 0 lb/a of N and at the average N rate, wheat yields in vetch systems were not significantly greater than in the no-vetch system.
Without hairy vetch in the rotation, wheat after sorghum responded to N rate with increases in plant height and yield at 30 and 60 lb/a, while plant N increased only at 90 lb/a. Notably, however, the incremental increase in wheat yield at 30 versus 60 lb/a of N was significant in the crop rotation without vetch, but not with vetch included as a prior winter cover crop.

Summary
The effects of Cruiser, Gaucho, and Prescribe seed treatments were evaluated on two corn hybrids, Asgrow RX799Bt and Midland 798. With a low level of chinch bug activity, most parameters used to characterize the crop were not affected by treatments. However, all insecticide treatments comparably increased the yield of one hybrid, Asgrow RX799Bt, by an average of 5.8 bu/a. Insecticide seed treatment effects also were evaluated on NC+ 271 and NK KS 560Y grain sorghum, both of which responded similarly in the presence of low chinch bug populations. Significant differences between Cruiser and Gaucho effects were observed in plant populations and in grain yield. Cruiser increased stands by 40% and yields by 11 bu/a, while Gaucho improved stands by 27% and yields by 7.5 bu/a. However, over a 3-year period, these two insecticides had a comparable impact on sorghum yield, with an average annual increase of 8 bu/a.

Introduction
Wireworms, flea beetles, and chinch bugs are insects that may affect stand establishment or development of corn and early-planted grain sorghum. Limited information is available concerning the response of these crops to insecticide seed treatment in the presence of low levels of these pests. Previous work with Gaucho on grain sorghum at Hesston showed that sorghum hybrids differed in their yield response. In April grain sorghum plantings, the average yield increases with Gaucho were 7 and 13 bu/a in 1996 and 1997, while in May plantings, corresponding increases were 12 and 14 bu/a. Low levels of chinch bugs were present in these experiments. However, in similar tests at four other locations across the state, little or no impact on sorghum yields was found in the absence of any significant insects. Analogous evaluations had not been done in corn. The experiment reported here was established in 2000 to determine the relative efficacy of Cruiser and Gaucho seed treatments on insects in corn or grain sorghum as well as to assess the impacts these pests may have on yields. Beginning in 200l, a third treatment, Prescribe, which is a higher rate of Gaucho, and a fourth treatment, a higher rate of Cruiser, were added to the corn investigation. This allowed comparison of both high and low rates of these two insecticide seed treatments.

Procedures
The experiment was conducted on a Ladysmith silty clay loam soil. In 2002, corn followed soybean, and sorghum was grown on an area with a history of continuous sorghum. Corn was fertilized with 90 lb N/a and 37 lb P 2 O 5 /a. Eight replications of two hybrids, Asgrow RX799Bt and Midland 798, with and without Cruiser, Gaucho, and Prescribe were planted on April 18, 2002, in 30-inch rows at 20,000 seeds/a. Weeds were controlled with preemergence application of Dual II Magnum + AAtrex 4L (1.33 pt + 1.5 qt/a). Plant population counts and seedling vigor ratings were obtained at 16 days after planting (DAP).
Corn was combine harvested on August 28.
Grain sorghum was fertilized with 115 lb/a of N. Hybrids NC+ 271 and NK KS 560Y, with and without Cruiser and Gaucho were planted in eight replications on May 7 in 30-inch rows at 46,090 seeds/a. Weeds were controlled with preemergence application of Dual II Magnum + AAtrex 4L (1.33 pt + 1 qt/a). Stand counts and seedling vigor ratings were made at 20 DAP. Grain sorghum was harvested on September 6, 2002.

Corn
Corn emerged at the end of April and reached silking stage in early July. Several modest rains in July and August allowed corn to survive the drouth-stressed growing season. A low population of chinch bugs was present and was not quantified. Insecticide treatments had no effect on corn stands, plant vigor, number of days to silking, or grain test weight (Table 6). With Cruiser at 5.1 oz/cwt, Asgrow RX799Bt had 6% less lodging than with no treatment. Other treatments did not affect lodging in this hybrid and none of the treatments impacted lodging in Midland 798. All insecticide seed treatments significantly increased yield of Asgrow RX799Bt and were comparable at an average of 5.8 bu/a. None of the seed treatments benefitted Midland 798 yield. The high rate of Cruiser tended (P=0.10) to increase yield of Asgrow RX799Bt more than the low rate; no effect of Gaucho rate was noted in this hybrid. Insecticides had no effect on corn yields in 2001 under the severe drouth; thus, no information on insecticide rate effects was obtained.

Grain Sorghum
More than 1 inch of rain fell within 5 days after planting. Sorghum initiated emergence at 10 DAP. Significant drouth stress during the summer months resulted in relatively low yields. Chinch bug populations were low and were not quantified. Cruiser and Gaucho increased sorghum stands by an average of 40% and 27%, respectively, and differences between these treatments were significant. Both insecticides increased plant vigor slightly at 20 DAP and also improved grain production. Cruiser increased sorghum yield by an average of 11 bu/a, which was significantly more than the 7.5 bu/a gain noted with Gaucho treatments. However, these treatments had nearly equal effects on sorghum yields over the 3-year period of this experiment, with an average increase of 8 bu/a. The number of days to half bloom, heads/plant, lodging, and grain test weight were not affected by the insecticides. Response in these parameters of the two hybrids was similar with both Gaucho and Cruiser treatments.

Summary
Two corn hybrids, NC+ 5790B and NC+ 5878B, respectively representing fixed-ear (D) and flex-ear types (F), were grown in a wheat rotation under minimum-till conditions at plant populations ranging from 14,000 to 26,000 plants/a. Yields were low because of drought stress. Highest yields occurred with 14,000 and 18,000 plants/a, decreasing by 12% at 22,000 and 26,000 plants/a. Number of ears/plant tended to decrease as populations increased. Grain test weight was not affected by plant population. Lodging increased significantly with stand levels in NC+ 5878B (F) but not in NC+ 5790B (D). This was the only hybrid by treatment interaction effect observed.

Introduction
The Kansas Corn Performance Tests historically have been planted at a constant population across all hybrids at a given location. Optimal populations are generally based on current K-State Research and Extension recommendations, as well as consideration of soil type, typical rainfall, fertility, and planting date. Seed companies often recommend a specific population range for each hybrid based on inhouse research. These recommendations are based on the observed reaction of each hybrid to changes in population. Typically, flex-ear hybrids are characterized as handling low populations better and not responding well to higher populations. Fixed-ear (determinate) hybrids are characterized as performing best under higher populations. As a result, some seed company representatives have questioned our policy of using a constant population for all hybrids at a given location.
This experiment was initiated in 2001 to determine if hybrid types (flex-ear vs. determinate) respond differently to plant population under existing dryland conditions and to provide a basis for either 1) the validation of current Kansas crop performance test practices or 2) additional studies on a broader scale to evaluate hybrid response characteristics.

Procedures
The experiment was conducted on a Smolan silt loam with pH 5.9, 2.5 % organic matter, and soil tests that were medium in available phosphorus and high in exchangeable potassium. In 2001 winter wheat was grown on the site, which was subsequently maintained with minimum tillage. Corn was fertilized with 125 lb/a of N and 37 lb/a of P 2 O 5 as 34-0-0 broadcast on April 16 and as 18-46-0 banded at planting. The experiment design was a randomized complete block with factorial combinations of two hybrids and four plant populations in four replications.
A fixed-ear (D) hybrid, NC+ 5790B, and a flex-ear (F) hybrid, NC+ 5878B, were planted at 31,000 seeds/a into moist soil on April 17, 2001. Temik 15G insecticide at 7 lb/a was applied in-furrow at planting. Weeds were controlled with preemergence application of Partner 65 DF + atrazine 90 DF (3.85 lb + 1.1 lb/a). Corn emerged at the end of April and was subsequently hand thinned to specified populations of 14,000, 18,000, 22,000 and 26,000 plants/a. Evaluations included maturity, lodging, ear number, yield and grain test weight. Plots were combine harvested on August 29.

Results
Moisture conditions were quite favorable for corn in the first months after planting. However, the season was characterized by drouth stress. Fewer days with extreme temperatures coupled with several modest, but timely summer rains prevented crop failure and insured low, but meaningful yields.
Length of time to reach half-silking stage increased slightly in both hybrids at the two highest plant populations (Table 8). Corn yields were low and tended to decline at 22,000 and 26,000 plants/a. Highest yields occurred with 18,000 plants/a, but were not significantly better than at 14,000 plants/a. Yields at the two highest populations averaged 12% less than at the lowest populations. NC+ 5790B (D) produced 7.7 bu/a more than NC+ 5878B (F). However, these hybrids had similar yield responses to plant population. Test weight was not affected by plant population. Number of ears/plant tended to decrease as plants/a increased, and this effect was similar in both hybrids. Lodging increased significantly in NC+ 5878B (F) at all populations greater than 14,000 plants/a, reaching a plateau of approximately 28% at 22,000 and 26,000 plants/a. NC+ 5790B (D) had little or no lodging. This was the only measured variable showing a significant hybrid by plant population interaction. LSD .05 4.9 5.9 NS 0.03 0.4 5 1 (D) = fixed-ear hybrid ; (F) = flex-ear hybrid. 2 Average of 4 replications adjusted to 56 lb/bu and 15.5% moisture. 3 Days from planting to 50% silking. 4 Probability of significant differential hybrid response to plant population; NS = not significant.

Summary
Twenty herbicide treatments were evaluated for crop tolerance and weed control efficacy in grain sorghum. Weed competition consisted of moderate large crabgrass and sunflower populations as well as dense stands of Palmer amaranth. Full rates of Dual II Magnum, Lasso, and Outlook as well as Bicep II Magnum, Bicep Lite II Magnum, Bullet, and Guardsman preemergence provided excellent control of large crabgrass. Paramount + AAtrex + COC and Guardsman + COC postemergence had very limited activity on large crabgrass up to 2 inches tall. Palmer amaranth control was excellent with full rates of Dual II Magnum, Lasso, and Outlook alone as well as with reduced rates in combination with all subsequent postemergence treatments. Bicep II Magnum and Bullet were the only preemergence treatments with good to excellent control of sunflower. However, postemergence treatments, with the exception of those involving Aim + AAtrex, were effective on sunflower. Outlook at 15 oz/a and Guardsman preemergence caused some stunting and/or unevenness of sorghum plant heights, but did not significantly affect stands. Several postemergence treatments, principally those involving either Banvel or 2,4-D, caused significant sorghum injury. However, symptoms of injury dissipated over time and were not well correlated with yields. While all herbicides greatly improved sorghum production, significant differences in grain yield occurred among treatments.

Introduction
This experiment evaluated grass herbicides, standard premix preemergence treatments, and alternative post emergence herbicides and herbicide combinations that may provide greater flexibility for growers with regard to grain sorghum rotation and cost.

Procedures
Winter wheat was grown on the experiment site in 2001. Soil was a Geary silt loam with pH 6.8 and 2.3% organic matter. A reduced tillage system with v-blade, sweep-treader, and field cultivator was used to control weeds and prepare the seedbed. Fertilizer nitrogen was applied at 99 lb/a as 46-0-0 in early June. Palmer amaranth and large crabgrass seed was broadcast over the area to enhance the uniformity of weed populations. Also, domestic sunflower was planted in four 30inch rows across all plots. Pioneer 8505 with Concep III safener and Gaucho insecticide seed treatment was planted at approximately 42,000 seeds/a in 30-inch rows on June 3, 2002. Seedbed condition was excellent. All herbicides were broadcast in 20 gal/a of water, with three replications per treatment (Table 9). Preemergence (PRE) applications were made shortly after planting with AI TeeJet 110025-VS nozzles at 29 psi. Postemergence treatments were applied with Turbo Tee 11003 nozzles at 20 psi on June 24 (EPOST) or June 26 (POST). EPOST treatments were applied to 0.5-to 3-inch Palmer amaranth, 4-inch domestic sunflower, and 0.5-to 2-inch large crabgrass in 5-to 8-inch sorghum. POST herbicides were applied to 0.5-to 3-inch Palmer amaranth, 4-to 5-inch sunflower, and 0.5to 3-inch large crabgrass in 6-to10-inch sorghum. Plots were not cultivated. Crop injury and weed control were rated several times during the growing season.
Sorghum was harvested September 24.

Results
Substantial rainfall began within hours after preemergence treatments were applied. Total precipitation for that day was 2.19 inches. An additional 3.55 inches of rain fell 1 week later. Mean air temperatures were near normal and precipitation was well above average in June.
Drouth stress occurred during the summer months, but timely, modest rains averted more deleterious effects on sorghum yields.
Outlook at 15 oz/a preemergence caused some stunting and unevenness of sorghum plant heights. Guardsman preemergence also resulted in minor disuniformity of emergence and plant heights. Sorghum stands were not significantly affected by any of the herbicide treatments.
Among postemergence treatments following Dual II Magnum or Lasso preemergence, Peak + Banvel, Ally + 2,4-D LVE, and Yukon caused significant injury in the form of leaning plants or tillers and rolled leaves. Ally + AAtrex + 2,4-D LVE and Permit + 2,4-D LVE caused somewhat less injury. Paramount + AAtrex + COC caused light chlorosis. Sorghum treated with Aim + AAtrex had very minor and inconsistent chlorotic spotting on leaves. All symptoms of injury dissipated over time.
Moderate large crabgrass and sunflower populations developed along with dense stands of Palmer amaranth. Reduced rates (33%) of Dual II Magnum, Lasso, and Outlook were used to minimize preemergence broadleaf weed control in treatments involving subsequent postemergence herbicides. Full rates of Dual II Magnum, Lasso, and Outlook as well as Bicep II Magnum, Bicep Lite II Magnum, Bullet, and Guardsman preemergence provided excellent control of large crabgrass. At reduced rates, Dual II Magnum and Outlook were less effective, but generally gave fair to good large crabgrass control that was significantly better than the reduced rate of Lasso. Paramount + AAtrex + COC postemergence had very limited activity on large crabgrass, and the efficacy of Guardsman postemergence also was low on crabgrass already up to 2 inches in height.
Palmer amaranth control was excellent with full rates of Dual II Magnum, Lasso, and Outlook alone as well as with reduced rates in combination with all subsequent postemergence treatments. Paramount + AAtrex + COC was less effective, but still provided good control. Poor to fair control of Palmer amaranth occurred with reduced rates of Dual II Magnum, Outlook, and Lasso. At these rates, Palmer amaranth control with Outlook and Lasso tended to be slightly better than with Dual II Magnum.
Sunflower control was good to excellent with Bicep II Magnum and Bullet preemergence. All other preemergence treatments were unsatisfactory.
On the other hand, most postemergence treatments effectively controlled sunflower. Exceptions were treatments involving Aim + AAtrex, which gave less than 75% control.
All herbicides significantly increased grain sorghum production. Highest yield occurred with Bicep II Magnum. A number of other treatments resulted in comparable yields. Significantly lower yields were obtained with Guardsman preemergence as well as with Dual II Magnum, Outlook, and Lasso alone. Sorghum grain moisture and test weights were not affected by treatments.

Summary
Twenty-two herbicide treatments were evaluated for crop tolerance and weed control efficacy in soybean. Dense large crabgrass and Palmer amaranth populations developed along with moderate sunflower stands. Large crabgrass control was good to excellent with a number of treatments, but was unsatisfactory with Flexstar + Fusion, Prowl followed by Raptor + Ultra Blazer, and with single applications of Roundup UltraMax or Touchdown. Palmer amaranth control was excellent with most treatments. Late application of Touchdown tended to diminish its efficacy on Palmer amaranth. Poor control of Palmer amaranth occurred with Prowl followed by Raptor + Ultra Blazer. Most treatments were effective on sunflower. However, Prowl followed by Raptor + Ultra Blazer failed to give acceptable sunflower control. Check plot soybean yields were reduced to zero by weed competition. All treatments benefitted soybean production. Drouth effects limited conclusions about yield response to treatments. Crop injury and weed control were not consistently correlated with soybean yield.

Introduction
Successful soybean production is dependent upon effective weed control. Growers may choose from a number of herbicide options that can accomplish this objective. These options include the use of relatively new herbicides alone or in combination with glyphosate. This experiment was conducted to evaluate various herbicides and herbicide combinations for weed control efficacy as well as soybean tolerance. Treatments in 2002 included Canopy XL preemergence followed by Roundup UltraMax + Synchrony STS postemergence; Boundary (new formulation) preemergence followed by Touchdown or nonglyphosate postemergence herbicides; and Touchdown and Roundup UltraMax application timing.

Procedures
Winter wheat was grown on the experiment site in 2001. The soil was a Smolan silt loam with pH 6.8 and 2.2% organic matter. A reduced tillage system with v-blade, sweep-treader, and field cultivator was used to control weeds and prepare the seedbed. Palmer amaranth and large crabgrass seed was broadcast over the area to enhance the uniformity of weed populations. Also, domestic sunflower was planted across all plots. Asgrow AG3302 Roundup Ready + STS soybean was planted at 104,540 seeds/a in 30inch rows on June 11, 2002. Seedbed condition was excellent. All herbicide treatments were broadcast in 20 gal/a of water, with three replications per treatment. Preemergence (PRE) applications were made shortly after planting with AI TeeJet 110025-VS nozzles at 29 psi (Table  10). Postemergence treatments were applied with Turbo Tee 11003 nozzles at 20 psi on June 24 (EPOST), July 1 (POST1), July 8 (POST2), and July 15, (POST3 and SEQ). EPOST treatments were applied to 0.5-to 3-inch Palmer amaranth, 4inch domestic sunflower, and 0.25-to 2-inch large crabgrass in 5-inch soybean with 1 to 2 trifoliate leaves. POST1 herbicides were applied to 2-to14inch Palmer amaranth, 12-inch sunflower, and 1to 5-inch large crabgrass in 7-inch soybean. POST2 herbicides were applied to 4-to 28-inch Palmer amaranth, 16-inch sunflower, and 4-to 9inch large crabgrass in 10-inch soybean. POST3 and SEQ treatments were applied to 19-to 40inch Palmer amaranth, 28-to 41-inch sunflower, and 12-to 18-inch large crabgrass in 16-inch soybean. Crop injury and weed control were evaluated several times during the growing season. Soybean was harvested September 27.

Results
Substantial rainfall totaling 2.19 inches occurred within 12 hours after planting. As a result, soil crusting was significant. Nevertheless, soybean emerged in 8 days with generally acceptable stands. Precipitation was well above average in June, but below normal in July and August. Drouth stress during the summer months was significant. Limited, but timely rains averted an even more disastrous effect on soybean yields.
Crop injury was observed with six of the treatments. Preemergence Squadron resulted in some soybean stunting. Flexstar + Fusion caused leaf crinkling and/or necrotic spots on soybean leaves. Ultra Blazer caused leaf burn.
Dense large crabgrass and Palmer amaranth stands developed along with moderate sunflower populations. A number of treatments provided good to excellent control of large crabgrass. However, poor control of large crabgrass resulted from Prowl followed by Raptor + Ultra Blazer and from Flexstar + Fusion. Also, in the absence of a preemergence grass herbicide, single application of Touchdown or Roundup UltraMax did not provide complete, season-long control of large crabgrass. Plots receiving early application of either of these two herbicides showed a decline in control late in the season because of subsequently emerging weeds.
Most treatments gave excellent control of Palmer amaranth. Intermediate season-long control was achieved with Flexstar + Fusion and single applications of Touchdown.
Late application of Touchdown tended to reduce efficacy. Poor Palmer amaranth control resulted from Prowl followed by Raptor + Ultra Blazer.
Weed competition reduced soybean yields to zero in untreated check plots, and all herbicide treatments significantly benefitted soybean production. Although differences of statistical significance were noted among soybean yields, drouth-induced variability placed limitations on conclusions about treatment effects. Crop injury and/or weed control were not always correlated with yields attributed to herbicide treatments.

Introduction
The 1952 Kansas legislature provided a special appropriation to establish the Irrigation Experiment Field in order to serve expanding irrigation development in north-central Kansas. The original 35-acre field was located 9 miles northwest of Concordia. In 1958, the field was relocated to its present site on a 160-acre tract near Scandia in the Kansas-Bostwick Irrigation District. Water is supplied by the Miller canal and stored in Lovewell Reservoir in Jewell County, Kansas and Harlen County Reservoir at Republican City, Nebraska. In 2001, a linear sprinkler system was added on a 32-acre tract 2 miles south of the present Irrigation Field. In 2002 there were 125,000 acres of irrigated cropland in north-central Kansas. Current research on the field focuses on managing irrigation water and fertilizer in reduced tillage and crop rotation systems.
The 40-acre North Central Kansas Experiment Field, located 2 miles west of Belleville, was established on its present site in 1942. The field provides information on factors that allow full development and wise use of natural resources in north-central Kansas. Current research emphasis is on fertilizer management for reduced tillage crop production and management systems for dryland, corn, sorghum, and soybean production.

Soil Description
The predominate soil type on both fields is a Crete silt loam. The Crete series consists of deep, welldrained soils that have a loamy surface underlain by a clayey subsoil. These soils developed in loesses on a nearly level to gently undulating uplands. The Crete soils have slow to medium runoff and slow internal drainage and permeability. Natural fertility is high. Available water holding capacity is approximately 0.19 in. of water per in. of soil.

Weather Information
The 2002 growing season was characterized by much below normal precipitation. The summer (June, July, August) rainfall total was the lowest since 1934.

Summary
The 2002 growing season was characterized by a very hot, dry summer. The summer rainfall total was the lowest since1934. The overall test average was only 53 bu/a. When averaged over all N rates, yields of sorghum grown in rotation with soybeans were 9 bu/a greater than continuous grain sorghum.
When averaged over nitrogen (N) rates, 1982-1995 yields were 23 bu/a greater in sorghum rotated with soybeans than in continuous sorghum. When no N was applied, rotated sorghum yielded 32 bu/a greater than continuous sorghum. In the continuous system, grain sorghum yield continued to increase with increasing N rate up to 90 lb/a. In the soybean rotation, sorghum yields increased with increasing N rate only up to 60 lb/a. When averaged over N rate, no-tillage grain sorghum rotated with soybeans reached mid-bloom 7 days sooner than continuous grain sorghum. Two knife-applied N sources (anhydrous ammonia and 28% UAN) were evaluated during 1982-1989. No grain sorghum yield differences resulted from N source. The 21-year soybean yield average was 33 bu/a. Soybean yields in 2002 averaged only 6 bu/a. In 1996, four additional N rates (120, 150, 180, and 210 lb/a) were added to the experiment. When averaged over the period 1996-2002, yields were greater in the rotated system than in the continuous sorghum at all levels of N. Addition of N did not compensate for the rotational effect. Yields in the continuous system continued to increase with increasing N rate up to 90 lb/a. Yields in the rotated system were maximized with application of 60 lb/a N.

Introduction
Crop rotations were necessary to maintain soil productivity before the advent of chemical fertilizers. Biological fixation of atmospheric N is a major source of N for plants in natural systems. Biological fixation through legume-Rhizobium associations is utilized extensively in agricultural systems. Using a legume in a crop rotation can reduce the N requirement for the following nonlegume crop. Other benefits of legume rotations include breaking disease and insect cycles, helping weed control programs, and decreasing the toxic effects of crop residues. This study evaluates N rates for continuous grain sorghum and grain sorghum grown in annual rotation with soybeans in a no-tillage production system.

Procedures
This study was established in 1980 at the North Central Kansas Experiment Field, located near Belleville, on a Crete silt loam soil. Data are reported from 1982. Treatments included cropping system (continuous grain sorghum and grain sorghum rotated with soybeans) and N rates (0, 30, 60, and 90 lb/a). In 1982In -1989, two N sources, anhydrous ammonia and ureaammonium nitrate solution (28% UAN), were evaluated. Both N sources were knife applied in the middle of rows from the previous year's crop. After 1989, anhydrous ammonia was used as the sole N source. In each year, N was knife applied 7-14 days prior to planting. Grain sorghum was planted at 60,000 seed/a, and soybeans were planted at 10 seed/ft in 30-in. rows. Soybean yields were not affected by N applied to sorghum and are averaged over all N rates. In 1996, four additional N rates (120, 150, 180, and 210 lb/a were added to the experiment to further define N response.

Results
Summer rainfall averaged only 45% of normal. Temperatures also were above normal in July and August. When averaged over all N rates, grain sorghum rotated with soybeans yielded 9 bu/a greater than continuous grain sorghum. In the continuous grain sorghum system, grain yields (1982)(1983)(1984)(1985)(1986)(1987)(1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995) continued to increase with increasing N rate up to 90 lb/a (Table 1). Sorghum yields in the rotated system were maximized with an application of 60 lb/a N. When no N was applied, rotated sorghum yielded 32 bu/a greater than continuous sorghum. When four additional N rates were added, yields were greater in the soybean rotation than in the continuous system at all levels of N ( Table 2). Addition of N alone did not make up yield losses in a continuous sorghum production system. Over the 21-year period , soybean yields averaged 33 bu/a and were not affected by N applied to the previous sorghum crop (Table 3). Two knife-applied N sources, anhydrous ammonia and 28% UAN, were evaluated from 1982-1989. When averaged over cropping system and N rate, yields were 60 and 59 bu/a for anhydrous ammonia and UAN, respectively. When averaged over N rates, the number of days from emergence to mid-bloom was 7 days shorter in the rotated system than in the continuous system (Table 2).

Summary
Field studies were conducted at the North Central Kansas Experiment Field, located near Scandia, on a Crete silt loam soil. The study consisted of 4 methods of starter fertilizer application (in-furrow with the seed, 2 inches to the side and 2 inches below the seed at planting, dribble on the soil surface 2 inches to the side of the seed, and banded over the row on the soil surface) and 5 starter fertilizer combinations. The starters consisted of combinations that included either 5, 15, 30, 45, or 60 lb/a N with 15 lb/a P 2 O 5 and 5 lb/a K 2 O. A no-starter check plot also was included in the experiment. Additional treatments included 2x2 starter with and without potassium. Dribble application of 30-30-5 starter fertilizer applied 2 inches to the side of the row also was compared to dribble directly over the row. Nitrogen was balanced so that all plots received 220 lb/a N, regardless of starter treatment. Starter fertilizer combinations were made using liquid 10-34-0 ammonium polyphosphate, 28% UAN, and potassium thiosulfate (KTS). When starter fertilizer was applied in-furrow with the seed, plant populations were reduced by over 8,400 plants/a compared with the no starter check. Corn yield was 33 bu/a lower when starter fertilizer was applied in-furrow than when applied 2x2. Dribble application of starter fertilizer in a surface band 2 inches to the side of the seed row resulted in yields equal to 2x2 applied starter. Grain yield and V-6 dry matter were lower in the starter treatments that only included 5 or 15 lb N/a. Other treatments were added in order to determine if K was responsible for any of the additional yield seen with the starter fertilizers or if N and P were the only elements necessary. Starter that included K improved yields (3-year average) by 12 bu/a.

Introduction
Use of conservation tillage including ridgetillage has increased greatly in recent years because of its effectiveness in conserving soil and water. In a ridge-tillage system, tillage at planting time is confined to a narrow strip on top of the ridge. The large amount of residue left on the soil surface can interfere with nutrient availability and crop uptake. Liquid starter fertilizer applications have proven effective in enhancing nutrient uptake, even on soils that are not low in available nutrients. Many producers favor in-furrow or surface starter applications because of the low initial cost of planter-mounted equipment and problems associated with knives and colters in high-residue environments. However, injury can be severe when fertilizer containing N and K is placed in contact with seed. Surface applications may not be effective in high residue situations. The objective of this research was to determine corn response to starter combinations using 4 different application methods.

Procedures
Irrigated ridge-tilled experiments were conducted at the North Central Kansas Experiment Field on a Crete silt loam soil. Analysis by the KSU Soil Testing Laboratory showed that initial soil pH was 6.2; organic matter content was 2.4%; and Bray-1 P and exchangeable K in the top 6 inches of soil were 40 and 420 ppm, respectively.
The study consisted of 4 methods of starter fertilizer application: in-furrow with the seed; 2 inches to the side and 2 inches below the seed at planting; dribble in a narrow band on the soil surface 2 inches to the side of the seed row; and banded over the row on the soil surface. In the row-banded treatment, fertilizer was sprayed on the soil surface in a 8 inch band centered on the seed row immediately after planting.
Starter consisted of combinations that included either 5, 15, 30, 45, or 60 lb N/a with 15 lb P 2 O 5 /a and 5 lb K 2 O/a. A no-starter check also was included. Nitrogen as 28% UAN was balanced so all plots received 220 lb/a, regardless of starter treatment. Additional treatments consisted of 2x2 placed starter with and without K. Dribbling starter fertilizer (30-30-5 rate) also was compared to the same starter rate dribbled directly over the row. Starter fertilizer combinations were made using liquid 10-34-0 ammonium polyphosphate, 28% UAN, and KTS.

Results
When starter fertilizer was applied in-furrow with the seed, plant populations were reduced by over 8,400 plants/a when compared with the no starter check (Table 4). Corn yield was 33 bu/a lower when starter fertilizer was applied in-furrow with the seed than when applied 2 inches beside and 2 inches below the seed. Dribble application of starter fertilizer in a narrow surface band 2 inches to the side of the seed row resulted in yields equal to the 2x2 applied starter. The band over the row treatment yielded more than the in-furrow treatment but less than the 2x2 or surface band treatments. Grain yield and V6 dry matter accumulation were lower in the starter treatment that only included 5 or 15 lb N/a. Addition of K to the starter mix increased 3-year average grain yields by 12 bu/a (Table 5). When averaged over the 3 years of the experiment, there were no differences in 2x2 placement and dribble on the soil surface.

Summary
No-tillage planting systems have generated interest in methods that allow total fertilizer application when planting, which would eliminate trips across the field. Previous research has shown that increasing the nitrogen (N) in starter fertilizer has been beneficial for no-tillage grain sorghum. Putting N and/or potassium (K) in direct seed contact, especially with urea, may cause seedling injury, so products that slow N release, such as polymer-coated urea, may be effective. Two polymer-coated urea products were examined in this study, Type I (CRU I) and Type II (CRU II). The CRU II product has a thicker coating than the CRU I and the N is released at a slower rate. The polymer coated urea product CRU I at rates of 30 and 60 lb N/a added to mono ammonium phosphate (MAP) as a direct seed-applied starter increased yields over MAP alone or MAP plus un-coated urea. The CRU II material added to MAP increased yields over the MAP alone at rates up to 90 lb/a. Uncoated urea reduced plant populations and yields at all rates of N.

Introduction
No-tillage planting of row crops has generated considerable interest in use of starter fertilizer. However, planters equipped with separate coulter/knives to place the fertilizer to the side and below the seed are not common in 12 row and larger planters, raising questions about putting fertilizer in the seed furrow as an alternative. Research at the North Central Kansas Experiment Field has shown a bigger response to 30-30-0 starter placed to the side and below the seed compared to a 10-30-0 starter similarly placed. Fertilizer rate and source must be limited when placed in direct seed contact to avoid germination injury. This is especially true for P and K. Polymer-coated fertilizers for slow release of N have been found to reduce the germination injury problem. This research was initiated to study the effects on germination and production of grain sorghum from applying a controlled released urea in direct seed contact.

Procedures
The study was initiated at the North Central Kansas Experiment Field near Belleville on a Crete silt loam soil. Soil pH was 6.0; organic matter was 2.4%; and Bray-1 P was 41 ppm. The grain sorghum hybrid Pioneer 8505 was planted without tillage into soybean stubble on May 21, 2002 at the rate of 54,000 seed/a. Starter fertilizer was applied in direct seed contact using 11-52-0 at 58 lb/a (a 6-30-0 starter rate) as the base for all starter treatments except for the N alone check treatments. Treatments with additional N in the starter were formulated using two controlledrelease polymer coated urea products, CRU I and CRU II from Agrium. The Type II product has a thicker polymer coat than Type I and therefore gives a slower N release. The polymer-coated urea products were compared with uncoated urea. Additional N was applied to grain sorghum plots at the V4 stage after plant samples had been taken for dry matter and nutrient analysis.

Results
The 2002 growing season was characterized by a very cool spring followed by a hot, dry summer. Summer (June, July, and August) rainfall averaged only 47% of normal resulting in the driest summer since 1934. Grain yields were very poor. Grain sorghum stands were greatly reduced when uncoated urea was placed in contact with seed as compared to the polymer-coated urea products (Table 7). Grain yields also were reduced in treatments receiving uncoated urea, regardless of N rate. Yield declined in the CRU II plus MAP plots when N rate exceeded 90 lb/a. Grain yields were increased significantly by the 30-30-0 and 60-30-0 CRU plus MAP starters compared to no starter or MAP alone. The yield increase from more N in the starter is consistent with previous research at North Central in which a 2x2-placed starter band of a 30-30-0 starter rate was significantly greater than the traditional 10-30-0 starter.
Our results suggest that in a no-tillage sorghum system, increasing the N in the starter can increase yield compared to a traditional starter or no starter. However, germination injury can occur if the starter is placed in direct seed contact. The polymer-coated urea for controlled N release used in this study reduced stand loss and made use of higher N starters possible in systems where the fertilizer is placed in-furrow in direct contact with the seed.

Summary
Conservation tillage production systems are being used by an increasing number of producers. Early season plant growth and nutrient uptake can be poorer in no-tillage than in conventional tillage systems. Strip-tillage may offer many of the soilsaving advantages of the no-tillage system while establishing a seed-bed that is similar to conventional tillage. Field studies were conducted at Belleville and Manhattan, KS to compare the effectiveness of strip tillage to no-tillage and to access the effects of fall vs spring applications of N-P-K-S fertilizer on growth nutrient uptake and yield of corn. The 2002 growing season was characterized by rainfall much below normal at both locations. The summer rainfall total at Belleville was the lowest since 1934. Corn yields were severely reduced by the hot, dry conditions. Even though grain yields were low, strip-tillage improved early season growth and nutrient uptake of corn at both locations. Grain yields of striptilled corn were significantly greater than notillage at Belleville but not at Manhattan. At the Belleville location, strip-tilled corn shortened the time from emergence to mid-silk by 7 days and also reduced grain moisture content at harvest. Strip-tillage appears to be an attractive alternative to no-tillage for Great Plains producers.

Introduction
Conservation tillage production systems are being used by an increasing number of producers in the central Great Plains because of several inherent advantages. These include reduction of soil erosion, increased soil water use-efficiency, and improved soil quality. However, early-season plant growth can be poorer in reduced tillage systems than in conventional systems. The large amount of surface residue present in a no-tillage system can reduce seed zone temperatures. Lower than optimum soil temperature can reduce the rate of root growth and nutrient uptake by plants. Soils can also be wetter in the early spring with notillage systems, which can delay planting. Early season planting is done in order for silking to occur when temperature and rainfall are more favorable. Earliness is an important component in successful dryland corn production in Kansas. Strip-tillage may provide an environment that preserves the soil and nutrient saving advantages of no-tillage while establishing a seed-bed that is similar to conventional tillage. The objectives of this experiment were to compare the effectiveness of strip-tillage to no-tillage and to assess the effects of fall applied, spring applied or split applications of N-P-K-S fertilizer on growth, grain yield, and nutrient uptake of corn grown in strip-till or no-till systems.

Procedures
Studies were conducted at the North Agronomy Farm at Manhattan, Kansas and the North Central Kansas Experiment Farm near Belleville to compare strip-tillage and no-tillage systems for dryland corn production. Fertilizer treatments at Manhattan consisted of 30, 60, 90 or 120 lb N/a with 30 lb P 2 O 5 , 5 lb K 2 O and 5 lb S/a. An unfertilized check plot also was included. At Manhattan, strip-tillage was done in soybean stubble in early March. The zone receiving tillage was 5-6 inches in width. Fertilizer was applied in both the strip-tilled and no-tilled plots at planting. Placement was 2 inches to the side and 2 inches below the seed. At the Belleville site, fertility treatment consisted of 40, 80, and 120 lb N/a with 30 lb P 2 O 5 , 5 lb K 2 O, and 5 lb S/a. Strip-tillage was done in wheat stubble in early October. Fall fertilizer in the strip-tillage system was placed 5-6 below the soil surface directly under the row. Another set of plots were strip-tilled in the fall but no fertilizer was applied until planting time in the spring. Spring fertilizer in both the strip-till and no-till plots was applied 2 inches to the side and 2 inches below the seed at planting. Nutrients were supplied as 28% UAN, ammonium polyphosphate (10-34-0), and potassium thiosulfate. Corn was planted in early April at both sites.

Results
Due to the very dry growing season, grain yields at both sites were very low and response to applied N was variable. All fertility treatments improved early season growth, nutrient uptake and grain yield over the unfertilized check plot (Table 8). When averaged over fertilizer treatment at Manhattan, strip-tillage improved early season plant growth and uptake of N, P and K compared to no-tillage. Even though the strip-tillage was done only a month before planting, the tilled zone provided a better environment for plant growth and development than did the no-till plots. There was no significant difference in grain yields between the strip-tillage and no-tillage plots.
At Belleville, strip-tillage improved early season growth, nutrient uptake, and grain yield of corn compared to no-tillage (Table 9). When averaged over fertility treatment, strip-tilled plots reached mid-silk 7 days earlier than no-tillage plots. The early season growth advantage seen in the strip-tilled plots carried over all the way to harvest. Grain moisture in the strip-tilled plots was 2.8 % lower than in no-till plots. In this very dry year, yield advantage may have been the result of the increased rate of development in the strip-till system. The corn plants reached the critical pollination period sooner in the strip-tilled plants while some stored soil water was still available. The soil water reserve was depleted 1 week later when the plants in the no-tillage plots reached mid-silk.
Strip-tillage does provide a better early season environment for plant growth and development, while still preserving a high amount of residue on the soil surface. This system may solve some of the major problems associated with conservation tillage, making it more acceptable to producers. Tillage

Summary
This 42-year experiment was conducted at the North Central Kansas Experiment Field, located near Scandia, on a Crete silt loam soil. The treatments applied to corn consisted of 6 N rates (40, 80, 160, and 200 lb/a) with or without 30 lb P 2 O 5 /a. An unfertilized check plot and a P only plot also were included. The soybean crop received no fertilization. Results of this study demonstrate the benefit of phosphorus fertilization even on soils not low in available P. Addition of P fertilizer increased yields, improved N use efficiency, lowered N requirement and hastened maturity of the corn crop.

Introduction
Nitrogen and phosphorus management are critical in crop production for both economic and environmental reasons. Application of N and P has significant economic benefits but can create unwanted water quality problems. Phosphorus fertilization is essential for optimum production of irrigated corn in central Kansas. Phosphorus is vital to plant growth and plays a key role in many plant physiological processes such as energy transfer, photosynthesis, breakdown of sugar and starches, and nutrient transport within the plant, as well as enhancing maturity of crops. Adequate P fertilization can help maximize corn grain yield and increase N use efficiency. A study was initiated in 1960 that assesses the effects of applied N, with or without P, on corn and soybean grown in annual rotation.

Procedures
This 42-year experiment was conducted at the North Central Kansas Experiment Field, located near Scandia, Kansas on a Crete silt loam soil. The experimental area was ridge-tilled and furrow-irrigated. The treatments consisted of 6 N rates ( 40, 80, 120, 160, and 200 lb/a) with or without 30 lb P 2 O 5 /a. An unfertilized check plot and a P only plot also were included. The experimental design was a 2 factor randomized complete block, replicated 4 times. The test area was arranged so that 12 corn rows were rotated with 12 adjacent soybean rows every other year. Each crop appears every year. Individual plots are 6 rows, 30 inches wide and 40 feet long. Initial Bray-1 P in the top 6 inches of soil (1959) was 80 ppm. Anhydrous ammonia was used as the N source and was applied 7-14 days before planting each year. Granular triple superphosphate (0-0-46) was used as the P source and was applied 2 inches to the side and 2 inches below the seed at planting.

Results
Averaged over the 42 years of this experiment, plots that received P yielded greater than the no P plots at all levels of N ( Figure 1). Addition of P also increased nitrogen use efficiency. Maximum yield in the plots that received P was achieved with 120 lb/a N, while in the no-P plots yields continued to increase with increasing N rate up to the 160 lb/a level. Phosphorus plays an important role in seed development and can hasten crop maturity. Figure  2 shows that application of P significantly reduced grain moisture at harvest. At the 120 lb/a N rate, grain moisture was reduced from nearly 20% without P to less that 15% with P. Maturity differences that were established early in growing season persisted up to harvest (Table 10). Applied P fertilizer reduced the number of thermal units need to go from emergence to midsilk at all levels of N.
Applied P fertilizer also improved the yield of soybean grown in rotation with corn When averaged over N-rates and years, yield of soybean with P was 61 bu/a and 51 bu/a without P. Soybean yield was not affected by N applied to the previous years's corn crop.
Annual application of 30 lb/a P 2 O 5 maintained soil test levels at nearly an even level until 1985. (Figure 3). However, soil test levels have declined in recent years. Corn grain yields were 11% greater for the period 1985 -2002 than for 1960-1984. This may indicate that the 30 lb P 2 O 5 rate may not be keeping pace with the higher removal rate. Soil test P has declined to half of the original value in the no P plots.

Summary
This experiment was conducted on a producer's field in the Republican River Valley. The soil was a Carr sandy loam. Treatments consisted of 2 plant populations (28,000 and 42,000 plants/a) and 9 fertility treatments. Fertility treatments consisted of 3 nitrogen rates (160, 230, and 300 lb/a). The N rates were applied in combination with: (1) current soil test recommendations for P, K, and S (at this site, was 30 lb P 2 O 5 /a), (2) 100 lb P 2 O 5 +80 lb K 2 O+40 lb S/a preplant with N applied in 2 split applications, and the higher rates of P, K, and S applied preplant with the N applied in 4 split applications. Additional treatments were also included in order to determine which elements were providing the most yield increase. At the higher fertility rates, grain yield at the higher plant population was 20 bu/a greater than at the lower population. Fertility levels must be adequate in order to take advantage of the added yield potential of modern hybrids at high plant populations. Applying N fertilizer in four applications was not superior to applying in two applications. Addition of P, K, and S fertilizer resulted in a 99 bu/a yield increase over the N alone treatment. A sound fertility program can increase yields and result in improved profits.

Introduction
With advances in genetic improvement of corn, yield levels continue to raise. Analysis of the KSU Irrigated Corn Hybrid Performance Test data for the years 1968-2000 show that yields have increased by a average of over 2 bu/year. New hybrids suffer less yield reduction under conditions of drought stress, insect infestations, and high plant population. Newer hybrids have the ability to increase yields in response to higher plant populations. For many reasons, both environmental and agronomic, reduced tillage production systems are growing in use by producers. Resent research from the Midwest indicates that in reduced tillage systems K responses can be achieved even though soil test levels are adequate. This research was designed to assess whether current soil test recommendations are adequate for new high-yield corn hybrids in reduced tillage production systems.

Procedures
This experiment was conducted on a producer's field located near the North Central Kansas Experiment Field, at Scandia, KS on a Carr sandy loam soil. Analysis by Kansas State University showed that initial soil pH was 6.8; organic matter was 2.0%; Bray 1-P was 20 ppm; exchangeable K was 240 ppm; S was 6 ppm. Treatments included 2 plant populations (28,000 and 42,000 plants/a) and 9 fertility treatments. Fertility treatments consisted of 3 nitrogen rates (160, 230, and 300 lb/a). The N rates were applied in combination with (1) current soil test recommendations for P, K and S (this would consist of only 30 lb/a P 2 O 5 at this site) , (2)100 lb/a P 2 O 5 +80 lb/a K 2 O+40 lb/a S applied preplant. N was applied in 2 split applications, (3) 100 lb/a P 2 O 5 + 80 lb/a K 2 O+40 lb/a S applied preplant with N applied in 4 split applications (preplant, V4, V10, and Tassel). A complete list of treatments is given in Table 11. Fertilizer sources used were ammonium nitrate, diammonium phosphate, ammonium sulfate, and potassium chloride. The experiment was fully irrigated, receiving 12 inches of irrigation water during the growing season. Data taken in addition to grain yield included whole plant samples at V6, V10, and tassel; ear leaf samples at silking; grain and stover samples at harvest.

Results
Summer (June, July, and August) rainfall was the lowest since 1934 and totaled only 4.5 inches. However, adequate irrigation water was available and corn grain yields were excellent. Averaged over fertility treatments, there was no significant difference between plant populations, although at the higher rate of P, K, and S, grain yield at the higher plant population was 20 bu/a greater than at the lower population (Table 12). Fertility levels must be adequate in order to take advantage of the added yield potential of modern hybrids at high plant populations. Additional P, K and S increased corn grain yield by 74 bu/a over the treatment receiving only 30 lb/ace P 2 O 5 . Applying N fertilizer in four applications was not superior to applying in two applications. Additional treatments also were included in the experiment in order to determine which nutrients were providing the most yield increase. Addition of each fertilizer element resulted in economically feasible yield increases. Addition of P, K and S resulted in a 99 bu/a yield increase over the N alone treatment (Table 13). This represents a gross revenue increase of $227.70/a (corn price of $2.30/bu) and a net increase of over $175.00/a. Even at low commodity prices, additional fertilizer inputs are justified. A sound fertility program can increase yields and result in improved profits.      2000and NC+7R37 and Pioneer 84G62 in 2001 and two corn hybrids (NC+5018 and Pioneer 34K77 at both locations). Hybrids were chosen on the basis of past performance in the KSU Crop Performance Tests. Additional treatments consisted of nitrogen (N) rates (0, 40, 80, 120, and 160 lb/a). Nitrogen as ammonium nitrate was side dressed after planting. Corn and grain sorghum were planted at optimum dates based on past research. When averaged over years, hybrid and N rate, grain sorghum at Belleville yielded 37 bu/a greater than corn. Even at Manhattan in a higher rainfall zone, grain sorghum yielded 12 bu/a more than corn when averaged over years, N rate and hybrid.

Introduction
Dryland corn acres continue to expand in north-central Kansas and south-central Nebraska. Government loan programs favor corn over grain sorghum. Sorghum is better adapted to drier environments than corn. Sorghum has the ability to remain dormant during drought and then resume growth; its leaves roll as they wilt, thus less surface area is exposed for transpiration; sorghum plants also exhibit a low transpiration ratio (lb of water required to produce a lb of plant biomass); and sorghum has a large number of fibrous roots that effectively extract moisture from the soil. It has been estimated that the absorption area of the root system of a sorghum plant is twice that of corn. This large absorption capacity and relatively small leaf area are major factors in sorghum drought resistance. Because sorghum is more drought tolerant, it is most often planted on less productive soils. In contrast, dryland corn is planted on the most productive acres. Comparisons of yield potential of corn and sorghum are limited because of the difference in productivity of the soils on which the crops are planted. This experiment directly compares corn and grain sorghum in the same environment.

Procedures
At Belleville, both corn and grain sorghum were planted into wheat stubble without tillage. At Manhattan the previous crop was grain sorghum. Corn (NC+5018 and Pioneer 34K77) was planted on April 22 at Belleville and April 25 at Manhattan. Seeding rate at both locations was 24,000 seed/a. Grain sorghum was planted on May 22 at Belleville and June 3 at Manhattan. Sorghum hybrids used were NC+7R83 and Dekalb 47 at Belleville and NC+7R37 and Pioneer 84G62 at Manhattan. Seeding rate was 60,000 plants/a. Corn and grain sorghum hybrids were selected based on their superior performance in previous KSU Performance Tests. The experiment also included N rates. Nitrogen rates of 40, 80, 120, and 240 lb/a were applied as ammonium nitrate after planting. A no N check also was included.

Results
Weather in 2002 was characterized by a very cool, wet spring followed by a very hot, dry period. Summer rainfall was the lowest since 1934 at the Belleville location. Corn yield was reduced by dry conditions at pollination in late June.

74
August was very dry at both locations. When averaged over N rates at Belleville, the corn hybrid NC+ 5018 yielded 25 bu/a and Pioneer 34K77 yielded 32 bu/a (Table 14). Average sorghum yield was 50 bu/a. Yields of both corn and grain sorghum were so low that little response to N was seen (Table 15). When averaged over N rates and hybrids, corn at Manhattan yielded 50 bu/a and sorghum yielded 58 bu/a. When averaged over the 3-years of the experiment, grain sorghum out yielded corn by 37 bu/a at Belleville and 12 bu/a at Manhattan. The ability of sorghum to avoid short term drought and still yield was illustrated by this experiment.  2002 2000-2002 2002 2000-2002 2002 2000-2002 2002 2000 - NC+7R37 (2001NC+7R37 ( -2002 N- Rate 2002Rate 2000Rate -2002Rate 2002Rate 2000Rate -2002Rate 2002Rate 2000Rate -2002Rate 2002 2000 -

KANSAS RIVER VALLEY EXPERIMENT FIELD Introduction
The Kansas River Valley Experiment Field was established to study how to effectively manage and use irrigation resources for crop production in the Kansas River Valley. The Paramore Unit consists of 80 acres located 3.5 miles east of Silver Lake on US 24, then 1 mile south of Kiro and 1.5 miles east on 17th. The Rossville Unit consists of 80 acres located 1 mile east of Rossville or 4 miles west of Silver Lake on US 24.

Soil Description
Soils on the two fields are predominately in the Eudora series. Small areas of soils in the Sarpy, Kimo, and Wabash series also occur. The soils are well drained, except for small areas of Kimo and Wabash soils in low areas. Soil texture varies from silt loam to sandy loam and soils are subject to wind erosion. Most soils are deep, but texture and surface drainage vary widely.

Weather Information
The frost-free season was 195 days at the Paramore Unit and 191 days at the Rossville Unit (173 days average). The last 32° F frosts in the spring were on April 5 at the Rossville Unit and on April 4 at the Paramore Unit (average, April 21). The first frost in the fall was on October 13 at the Rossville Unit and on October 16 at the Paramore Unit (average, October 11). Precipitation was below normal at both fields (Table 1). Irrigated corn and soybean yields were generally good.

Summary
Four soybean varieties of maturity groups II, mid-III, late-III, and mid-IV were planted at 4 dates from mid-April to late June/early July from 1999 to 2002. No significant yield differences among soybean varieties were observed. In 1999, there were no significant differences in yield due to planting date, but in 2000 yields of the first two planting dates were higher than the last two planting dates. At least part of this yield difference was attributed to poor stands attained at the 3rd and 4th planting dates because of dry weather. It appears from this study that maturity group does not affect yield of irrigated soybeans greatly with the earlier plantings, but if the planting date is delayed much beyond June 1, then the mid-III to late-III soybean maturities are the best choice.

Introduction
The flexibility to plant crops of choice rather than to plant to maintain base acres of a farm program crop encourages crop rotations. Soybean acres continue to increase in Kansas. Soybean tolerance to a wide range in planting dates has helped the widespread acceptance of this crop. Nevertheless, most crops have an optimum planting date that can differ by both region and cultivar. Little current information is available in Kansas concerning soybean planting dates with modern cultivars. The objective of this study is to determine the optimum planting date for soybeans from a wide range of maturities over several environments in Kansas. Six similar studies were located across eastern Kansas in 1999 with 3 western Kansas sites added in 2000. This project is supported by the Kansas Soybean Commission with check-off funds.

Results
Planting dates varied from the desired dates from year to year because of weather conditions. Fairly poor stands were obtained with the third and fourth plantings in 2000 because of dry soil conditions. The first frost in the fall hastened the maturity of the fourth planting of the mid-IV soybeans even in 2001, when it was later than usual. Maturity was delayed by 18 days (average) from the first planting date to the fourth planting date (57 days later planting, average). There was a difference of 19 days in average maturity between the group II and mid-group IV soybean (Table 2).
A positive interaction of planting date x variety was observed. The fourth planting date delayed the maturity of the Grp. II soybeans more than the other varieties. The maturity of the mid-IV variety was affected less by delayed planting date than the other varieties.
Soybean plants were generally shortest when planted in late June/early July (Table 3). The second and third planting dates were the tallest and similar in height, with the early planting date being slightly shorter. The Grp. II soybeans were shortest and the Grp. IV soybeans were tallest, with the mid-and late-III soybeans being intermediate and similar in height.
No significant yield differences were observed in 1999; however, in 2000, yields of the two earlier planting dates were higher than the last two planting dates (Table 4). The poor stands obtained at the third and fourth planting dates likely had a large influence on the lower yields. In 2002, Grp. II soybean had lower yields at all planting dates, which was attributed to a somewhat poor stands obtained with low germination seed. Also, some shattering had occurred with the Grp. II soybean in the first 2 planting dates (esp. the first planting date) before the plots could be harvested. The Grp. II soybeans would have been closer to the yield of the other varieties if they had been timely harvested. It appears from this study that maturity group does not affect yield of irrigated soybeans greatly with the earlier plantings, but if the planting date is delayed beyond about June 1, then the mid-III to late-III soybean maturities are the best choice.

Summary
Two studies evaluating N rates on corn following soybeans are summarized. Study 1 compared N rates on continuous corn and corn following soybeans with a complete set of data each year from 1979 -96. Study 2 evaluated N, P, and K treatments applied to corn following soybeans in alternate (odd) years from 1983 -2001. In both studies, little N response was obtained above 160 lbs N/a. In Study 1, continuous corn yielded 10-12 bu/a less than the corn/soybean rotation, even at the high N rate.

Introduction
When these studies were started, much of the corn in the Kansas River Valley was continuous corn. Research in other areas indicated that corn/soybean rotations benefitted both crops. These studies were designed to evaluate the effect of corn/soybean rotation and N rates.

Procedures
Study 1 evaluated N rates on corn/soybean rotations from 1978-1996. Nitrogen rates of 0, 75, 150, and 225 lbs N/a were used. For this summary, the continuous corn and the corn/soybean rotation plots were used. A corn/corn/soybean rotation was also included in the study but is not reported in this summary because results indicated second year corn following soybeans responds to N rate similar to continuous corn. A starter fertilizer including 130 lbs/a of 8-32-16 was applied as a 2x2 band at planting.
Study 2 included in this summary was initiated in 1972 at the Topeka Unit to evaluate the effects of nitrogen (N), phosphorus (P), and potassium (K) on irrigated soybeans. From 1983-2001, the study was changed to a corn/soybean rotation with corn planted in odd years. Nitrogen rates at the start of the study were 40, 80, 160, and 240 lb N/a. In 1997, the 40 lb N/a rate was changed to 120 lb N/a. This study summarizes these N rates over the plots receiving like amounts of P and K. No starter was used on this study. Both studies were planted to adapted corn hybrids in mid-April at 26,200 seed/a, except Study 2 was planted at 30,000 seed/a from 1998-2001. Herbicides were applied preplant, incorporated each year. The plots were cultivated, furrowed, and furrow irrigated as needed. A plot combine was used for harvesting grain yields.

Results
The 0 N plots in Study 1 showed a 55 bu/a yield advantage for the corn/soybean rotation compared to continuous corn (Table 5). Additional N on continuous corn reduced this yield advantage to 10-12 bu/a, but could not completely compensate for the rotation advantage. Average corn yields in Study 2 from 1983 through 1995 (7-years) and for 1997-2001 (3 years) are shown in Table 6. Corn has been grown in odd years in this study and soybean grown in even years. No continuous corn was included in this study. However, in both studies, the yield response to N rate reached a plateau at about 160 lb N/a. Application of N above this rate did not result in additional economic yield on a corn/soybean rotation.

Summary
This study was conducted at the Rossville Unit. Timeliness of application is a major factor in determining effective postemergence weed control. The complete postemergence treatments gave excellent control of large crabgrass, Palmer amaranth, and common sunflower this year because of timely rainfall and lack of rainfall for germination of new weeds. Most herbicide treatments used gave good to excellent control on weeds in this test.

Introduction
Chemical weed control and cultivation have been used to control weeds in row crops to reduce weed competition, which can reduce yields. Results of 17 selected treatments from a weed control test that included 34 preemergence and/or postemergence herbicide treatments are presented in this paper. The major weeds evaluated in these tests were large crabgrass (Lacg), Palmer amaranth (Paam), and common sunflower (Cosf).

Procedures
This test was conducted on a Eudora silt loam soil previously cropped to soybeans. The test site had a pH of 6.9 and an organic matter content of 1.1%. Garst 8342 IT hybrid corn was planted April 24 at 30,000 seeds/a in 30-inch rows. Anhydrous ammonia at 150 lb N/a was applied preplant, and 120 lb/a of 10-34-0 fertilizer was banded at planting. Herbicides were broadcast in 15 gal water/a, with 8003XR flat fan nozzles at 17 psi with 3 replications per treatment. Preemergence (PRE) applications were made April 25. Spike (SP) treatments were applied May 10 to 1-2 leaf corn, large crabgrass and palmer amaranth seedlings, and common sunflower up to 1 inch. Early postemergence (EP) treatments were applied May 29 to 5 leaf corn, 1-2 inch large crabgrass, 1-4 inch Palmer amaranth, and 2-8 inch common sunflower. The mid-postemergence (MP) treatments were applied June 7 to 6 leaf corn, 1-2 inch large crabgrass (when present), 1-4 inch Palmer amaranth, and 2-8 inch common sunflower. Populations of all 3 weed species were moderate to heavy. However, crabgrass and Palmer amaranth populations were generally fairly light at postemergence in plots receiving a preemergence treatment.
Plots were not cultivated. Crop injury and weed control ratings reported were made June 11 and July 16, respectively. The first significant rainfall after PRE herbicide application was on May 5 (1.17 inches). The first sprinkler irrigation occurred on June 21. The test was harvested September 23 using a modified John Deere 3300 plot combine.

Results
Light rains of 0.08 and 0.23 inch occurred 2 and 3 days after planting with a significant rainfall of 1.17 inch occurring 11 days after planting. Very little crop injury was observed (Table 7). Weed control was relatively good for all treatments, except for Topnotch + Hornet, which rated lower in large crabgrass and common sunflower control. This treatment has usually resulted in excellent control of this weed spectrum, but did not this year. Weed control with the complete postemergence treatments were good to excellent, except that Celebrity Plus was a little weak on large crabgrass. However, when evaluating these materials, it needs to be noted that the application was timely (small, actively growing weeds) and little rainfall was obtained after application to germinate new weeds. The large LSD of 40 bu/a indicates that yields from this site were extremely variable and decisions on what herbicide to use should be based more on the weed control ratings, not the grain yield.

Summary
This study was conducted at the Rossville Unit. The combination of a preemergence application of Boundary + a postemergence application of Touchdown resulted in better weed control than Boundary, PRE or one application of Touchdown, postemergence, regardless of timing of application. One application of glyphosate, alone was not sufficient for satisfactory weed control; a 2-pass program of glyphosate was required. A preemergence treatment containing sulfentratzone (Authority) resulted in excellent control of ivyleaf morningglory. This study emphasizes the fact that a proper application of a preemergence herbicide, even at a reduced rate, followed by a postemergence application of glyphosate, can be an effective weed control program and give the producer more flexibility in timing of the glyphosate application.

Introduction
Chemical weed control and cultivation have been used to control weeds in row crops to reduce weed competition, which can reduce yields. Results of 16 selected treatments from a weed control test that included 27 preemergence and/or postemergence herbicide treatments are presented in this paper. The weeds evaluated in these tests were large crabgrass (lacg), Palmer amaranth (paam), common sunflower (cosf), and ivyleaf morningglory (ilmg)
P5 (5 wks after planting) treatments were applied June 24 to 4 trifoliate soybean, 2-4 inch large crabgrass, 4-10 inch Palmer amaranth, 6-14 inch common sunflower, and 1-4 inch ivyleaf morningglory. P6 (6 wks after planting) treatments were applied July 3 to 5 trifoliate soybean, 2-6 inch large crabgrass, 12-16 inch Palmer amaranth, 12-16 inch common sunflower, and 2-4 inch ivyleaf morningglory. Populations of large crabgrass, Palmer amaranth, and common sunflower were heavy, while populations of ivyleaf morningglory were light to moderate and variable. Plots were not cultivated. Weed control ratings reported were made August 12. The first significant rainfall after PRE herbicide application was on May 24 (0.49 inch). The first sprinkler irrigation occurred on June 21. The test was harvested November 8 using a modified John Deere 3300 plot combine.

Results
No crop injury was observed with these treatments. In the first set of treatments, Boundary was applied PRE at a low rate, and then Touchdown was applied at 4, 5, and 6 weeks after planting (P4, P5, P6) either alone or following Boundary in an effort to evaluate the effect of different timings of application of glyphosate, with and without a low rate PRE herbicide. Treatments with Touchdown and Roundup Ultra Max applied at 3 and 6 weeks after planting were also compared to these treatments, as were other combinations of PRE + Post herbicides. The low rate of Boundary alone resulted in fair control of lacg and paam, poorer control of cosf, and little control of ilmg. Touchdown alone at P4 and P5 resulted in fair to poor control of lacg and paam and little or no control of ilmg. Delaying application of Touchdown alone to P6 resulted in better weed control, but not much difference in yield. One treatment of Touchdown gave excellent control of cosf regardless of timing. This is because most sunflowers germinate in a short period of time and don't usually germinate later in the growing season. The combination of Boundary PRE + Touchdown resulted in better weed control and grain yield than Boundary or Touchdown alone. Boundary + Touchdown at P5 tended to give the highest yield, but yields in this test were quite variable, as indicated by the high LSD(.05) of 18.4 bu/a. The 2-pass program of Roundup Ultra Max gave a little better control of lacg and paam than that of Touchdown, although in other tests, there have been no differences, or results tended to be better for Touchdown.
The other treatments including reduced PRE herbicide rates + glyphosate or glyphosate + another postemergence herbicide gave good to excellent control of lacg, paam, and cosf. Sulfentrazone (Authority) has good activity on morningglory as does Canopy XL (sulfentrazone + chlorimuron) and resulted in excellent ilmg control. Even the reduced rates of Authority + FirstRate (3.5 + 0.4 oz) followed by Glyphomax Plus, resulted in equivalent weed control and grain yield as the full rates (5.33 and 0.6 oz). This emphasizes that a program of a reduced rate of the proper PRE herbicide followed by glyphosate can be an effective weed control program and give a producer more flexibility in timing of the glyphosate application. Yields in this test were fairly variable as indicated by the large LSD of 18.4 bu/a. Herbicide use decisions from this data should be determined more by the weed control ratings than by yield.

NORTHWEST RESEARCH-EXTENSION CENTER Introduction
The Colby Branch Experiment Station was authorized by the State Legislature in 1913 and established in 1914 on land purchased by the Thomas County Commissioners and deeded to the state for experimental purposes. ". . . the Colby Station has been a center for studies and services aimed primarily at advancing and developing the agricultural interests in northwest Kansas." 1 Topics of interest in early years included methods of dryland farming, irrigating small acreages, and dairying, with emphasis on crop improvement and soil management. Since the 1950s, emphasis was given to studies in soil and weed management, irrigation, soil fertility, sheep production, variety testing, and crop improvement. Production of foundation wheat seed provides a quality source of public varieties. The integration of research and extension functions was formalized by renaming the station as Northwest Research-Extension Center (NWREC) in 1987.

Soil Description
The thick fertile silt-loam soils on the NWREC site are typical of those on several million acres of the High Plains of western Kansas, eastern Colorado, and western Nebraska. The predominant soil type is Keith silt loam, which has a buried soil on the station acreage. In addition, Ulysses silt loam, Richfield silty clay loam, and Goshen silt loam occur in lesser amounts. 1 These soils have developed in wind-blown silts, called loess, on uplands; have relatively slow runoff and high capacity for available water; and have high base saturation throughout the profile. The surface organic matter of these soils typically exceeds 1%, with surface pH exceeding 7.0, with pH exceeding 8.0 at localities throughout the region. Depth to free calcium carbonate (lime) is 16 to 19 inches for the Richfield and Keith series. Reduced tillage and mineral fertilizers can lower the pH in the surface soil layer.

Weather Information
Water typically limits crop productivity in rain-fed, semi-arid cropping regions.

Summary
Intensive crop sequences add feed grain (corn, grain sorghum) and oilseed (sunflower, soybean, canola) crops to winter wheat-fallow sequences to reduce evaporative losses in fallow periods and increase land productivity. Cropping sequences cover 3-year cycles of wheat, feed grain (corn or grain sorghum), and oilseed (sunflower, soybean, canola) or fallow; as well as wheat-fallow (2-year cycle) and wheat-corn-sunflower-fallow (4-year cycle). Though crop sequence effects are just becoming established, some emerging trends indicate the following: • Land productivity varies with rainfall among years.
• Wheat productivity benefits from summer fallow.
• Grain sorghum productivity exceeds corn when limited by water.
• Stand establishment, timing, and amounts of water limit oilseed productivity.
Annualized productivity, averaged over 2001 and 2002 growing seasons, indicates highest land productivity for wheat-fallow and wheatsorghum-fallow sequences. These sequences, common in western Kansas, appear to sustain land productivity while permitting more intensive cropping with an oilseed crop when sufficient moisture is available.

Introduction
Available water frequently limits productivity in semi-arid cropping systems. The wheat-fallow system accumulates water over a 2-year period, producing a single wheat crop. Tillage, providing weed control, often leaves the soil exposed to evaporative and erosive forces. Frequently, more precipitation is lost to evaporation than used by a growing wheat crop. More intensive crop sequences use feed grains (corn, grain sorghum) and oilseeds (sunflower, soybean, canola) to reduce evaporative losses in fallow periods and increase land productivity. The objective of this study is to compare seed yield, water use, and soil quality factors for 10 cropping sequences.
Crop management is intended to minimize evaporative loss of water, maximize grain productivity, and maximize soil water recharge. Full-season, adapted-feed-grain cultivars are planted at conventional periods; short-season oilseed cultivars are planted early in continuous cropping sequences to permit wheat planting following harvest. Cultural practices are summarized in Table 1.
Crop water use is measured by precipitation and change in soil profile water content from emergence to flowering to harvest (physiological maturity). Leaf area at flowering is measured by Li-Cor 2000 plant canopy analyzer. Yield components (stand, mid-vegetative and harvest; flowering units, seed weight) and above-ground biomass are hand-sampled at maturity. Seed yield is also measured by machine-harvest, using a plot combine (platform or corn header). For conditions with poor stands, yield potential is estimated from hand-harvested samples. Yields are adjusted to standard moisture contents. Annualized grain yield, computed as the average yield (lbs/a) among all phases (including fallow) of a given sequence, provides a uniform measure of land productivity.

Results
The study was established in 2000, planted into uniform wheat stubble harvested in 1999. Thus, the 2002 harvest was the first year reflecting crop sequence effects for 3-year cycles. Crop yields and annualized grain yield (AGY) are presented for each sequence, by year, in Table 2. Though crop sequence effects are just becoming established, the following trends were observed during these drought years: • Land productivity varies with rainfall among years.
• Wheat productivity benefits from summer fallow.
• Grain sorghum productivity exceeds corn when limited by water.
• Stand establishment, timing, and amounts of water limit oilseed productivity.
• Timing of precipitation affects herbicide activity; drought can reduce the effective control of weeds by pre-emergent and contact herbicides.
Crop sequences are known to alter soil quality factors, as well as soil water status; so these preliminary observations require confirmation from long-term data that include a broad range of weather conditions. Annualized productivity, averaged over 2001 and 2002 growing seasons (when effects of fallow are present), indicate highest land productivity for wheat-fallow and wheat-sorghum-fallow sequences (Figure 3). Adding an oilseed crop reduced AGY by lowering wheat yields, particularly in the severe drought of 2002. The wheat-fallow and wheat-sorghum-fallow sequence, common in western Kansas, appear to sustain land productivity while permitting more intensive cropping with an oilseed when sufficient moisture is available.
Modifications of crop culture for a second 3-year cycle will likely include: • Replacing corn with grain sorghum in the 4-year cycle to improve productivity • Delaying planting and selecting adapted cultivars of sunflower and soybean to improve yield potential and avoid pest damage • Seeding canola after rainfall events for improved stand establishment • Utilizing Raptor (immidazolinone) herbicide for post-emergent weed control in oilseed crops.
The study is expected to continue for a minimum of four 3-year cycles to establish longterm crop sequence effects in this environment.

Summary
The sunflower stem weevil, Cylindrocopturus adspersus (LeConte), is a pest of cultivated sunflower. The objective of this study was to test insecticides using different timing strategies and different planting periods to manage weevil densities to reduce losses of sunflower productivity from lodging. Planting periods ranged from early May to mid-June. Delaying planting until late May resulted in higher yields for non-treated sunflower in 2002, but not in 2001. Lack of response to planting date in 2001 is attributed to the effects of uncontrolled sunflower moth infestations. Insecticide treatments improved seed yields by at least 600 lb/a for all planting periods in both years. These results support economic control measures for stem weevil pests.

Introduction
The sunflower stem weevil, Cylindrocopturus adspersus (LeConte), is a pest of cultivated sunflower. Since 1993 damage has been reported and populations have been increasing in eastern Colorado, western Kansas, and Nebraska. Adult sunflower stem weevils emerge from overwintered stalks in mid-to-late June in the Northern Plains. Females lay their eggs at the base of sunflower stalks. Larvae feed apically in the stems until early August and then descend to the lower portion of the stalk or root crown by late August and excavate over-wintering chambers by chewing cavities into the stem cortex. High larval populations can weaken the stem by tunneling, destroying pith, or excavating over-wintering chambers. Subsequent stem breakage and lodging will cause a loss of the entire head prior to harvest. Models for degree-day prediction of weevil emergence have been developed for both the Northern and Central Plains, but have not been used for timing of insecticide treatment. The objective of this study was to test insecticides using different timing strategies and different planting periods to manage weevil densities to reduce losses of sunflower productivity that result from lodging.

Procedures
Sunflower seed (Triumph 652, oilseed at 23,500 seeds/a) was planted in 30-inch rows in three planting periods, beginning mid-May through mid-June, in disked and harrowed soil (Keith silt loam), using a fluted coulter and double-disk opener. Soil fertility was amended with 90 lb N/a and 30 lb P 2 O 5 /a. Weeds were controlled by herbicide (Glyphosate, or Roundup, 8 oz/a; sulfentrazone, or Spartan, 3 oz/a and pendimethalin, or Prowl, 3.5 pt/a). Sunflower crop development (leaf appearance and reproductive growth stage) was noted at weekly intervals. Canopy leaf area was measured at flowering (R5) using a Li-Cor 2000 canopy analyzer. Soil water was measured at emergence, flowering, and maturity. Crop stand (V8 and R9), yield components and above-ground biomass were measured at physiological maturity from two 17 ft by 5 inch rows from each of four replicated plots. Plots were also machine-harvested when seed moisture was less than 12%. Seed was analyzed for moisture content, test weight, seed weight, and oil content (oilseed) or seed size distribution (confection). In 2001, trials included insecticide application (carbofuran, or Furadan 4F, 16 oz/a) timing based on plant growth stage (V5 to V10, V10 to R1). In 2002, trials included insecticide application timing based on both plant growth stage and the use of degee-day models for weevil emergence to determine which is most effective. All treatments included untreated controls and were replicated four times. The degree of control was measured by comparing the percentage of plant lodging and the number of weevil larvae per stalk. Control of the sunflower longhorned beetle was measured by comparing the populations of this pest found in dissected stalks.

Results
Severe sunflower moth infestations likely reduced yields in 2001 by 45% relative to 2002 yields 1 . Results of this study suggest crop yields with control of stem pests approximates the relative yield potential of the two years. Delaying planting until late May resulted in higher yields for non-treated sunflower in 2002, but not in 2001. Lack of response in 2001 is attributed to the effects of uncontrolled sunflower moth infestations. Insecticide treatments improved seed yields by at least 600 lb/a for all planting dates in both years at the irrigated site (Tables 3 and 4). Greatest seed yield occurred with later insecticide treatment in 2001 (Table 4). These results support economic control measures for stem weevil pests.

Summary
Available soil water can limit sunflower productivity by direct effects on canopy function, as well as indirect effects on canopy and seed development. The objective of this study was to determine effects of planting period on oilseed and confection sunflower development, seed yield and quality, and water use in rain-fed, semi-arid cropping systems. Planting periods ranged from early May to mid-June. The highest yields for both oilseed and confection crops resulted from the early-or mid-June planting period in both years. Relative yield losses occurred in both years for both oilseed and confection crops planted in the early-May period. These results confirm earlier recommendations to plant sunflower in June when moisture is adequate for rapid emergence and improved crop productivity.

Introduction
Sunflower yield can be reduced by pest infestation, heat stress, and/or water deficits. Optimal planting periods avoid or minimize the impacts of these environmental stress factors on yield. Knowledge of these effects can guide management decisions to sustain or improve water management for sunflower productivity in rain-fed and limited-irrigation crop systems. The objective of this study was to determine effects of planting period on oilseed and confection sunflower development, seed yield and quality, and water use in semi-arid cropping systems.

Procedures
Sunflower seed (SF 187, oilseed at 18,000 seeds/a and Sigco 954, confection at 14,000 seeds/a) was planted (30-inch rows, using a fluted coulter and double-disk opener) in four planting periods beginning early May through mid-June, into a Keith silt loam soil, fallowed after the previous crop. Soil fertility was amended with 90 lb N/a and 30 lb P 2 O 5 /a. Weeds were controlled by herbicide (Glyphosate, or Roundup, 8 oz/a; sulfentrazone, or Spartan, 3 oz/a and pendimethalin, or Prowl, 3 oz/a). No insecticide was applied for stem or head pests.
Sunflower crop development (leaf appearance and reproductive growth stage) was noted at weekly intervals. Canopy leaf area was measured at flowering (R5) using a Li-Cor 2000 canopy analyzer. Soil water was measured at emergence, flowering, and maturity. Crop stand (V8 and R9), yield components, and above-ground biomass were measured at physiological maturity from two 17 ft by 5 inch rows from each of four replicated plots. Plots were also machine-harvested when seed moisture was less than 12%. Seed was analyzed for moisture content, test weight, seed weight, and oil content (oilseed) or seed size distribution (confection).

Results
Below-normal precipitation and above-normal evaporative demand reduced yield potential of rain-fed sunflower by 24% in 2000, relative to 2001. 1 A heavy infestation of sunflower moth reduced yield potential of the irrigated crop by 24% in 2001, relative to 2000 1 , despite insecticide application. Seed quality in this study was poorer in 2001 relative to 2000. Oilseeds tended to lower oil content (Table 5) and confections tended to smaller seed size (Table 6) in 2001 relative to 2000. Weather and insect pests likely affected yield response to planting periods in the two years.
The highest yields for both oilseed and confection crops resulted from the early-or mid-June planting period in both years. Relative yield losses occurred in both years for both oilseed and confection crops planted in the early-May period.
Fewer seeds were harvested per plant for the early planting period relative to later periods. Delayed emergence and low plant populations occurred each year, affecting both crop types. However, yield compensation occurred with more harvested seeds per plant and larger seed size.
T h e s e r e s u l t s c o n f i r m e a r l i e r recommendations 2 to plant sunflower in June when moisture is adequate for rapid emergence and improved crop productivity.

Summary
Available soil water can limit sunflower productivity by direct effects on canopy function, as well as indirect effects on canopy and seed development. The objective of this study was to determine effects of water deficits on oilseed sunflower development, seed yield and quality, and water use in semi-arid cropping systems. Supplemental water treatments were applied to sunflower during vegetative, reproductive, or both growth stages. Seed yields ranged from 2100 to 2700 lbs/a in 2000, and were reduced by 38% in 2001. Reduced yields in 2001 are attributed to severe sunflower moth infestation (24% reduction) and inadequate irrigation amounts (14% reduction). Crop water use appears to be limited by available soil water when relative soil water (in the wettest soil layer) is less than 60% of water holding capacity. Available water affects crop canopy development as well. Results from related studies suggest control of insect pests is required to achieve yield potential of supplemental water for improved water use.

Introduction
Available soil water frequently limits grain productivity in rain-fed, semi-arid cropping systems of the central Great Plains. Water use for sunflower can exceed that of other summer crops, due to higher transpiration rates, greater rooting depth, and extraction of soil water. Available soil water can limit sunflower productivity by direct effects on canopy function, as well as indirect effects on canopy and seed development. Knowledge of these effects can guide management decisions to sustain or improve water management for sunflower productivity. Improving the productive use of water by sunflower cultivars would enhance the array of management alternatives for farmers seeking profitable crops for rain-fed and limited irrigation crop systems in this region. The objective of this study was to determine effects of water deficits on oilseed sunflower development, seed yield and quality, and water use in semi-arid cropping systems.

Procedures
Sunflower seed (SF 187, oilseed) was planted (30-inch rows) in early June, into disked and harrowed soil (Keith silt loam), in 20 ft x 90 ft experimental plots, using a fluted coulter and double-disk opener. Soil fertility was amended with 100 lb N/a and 30 lb P 2 O 5 /a. Weeds were controlled by herbicide (sulfentrazone, or Spartan, 3 oz/a and pendimethalin, or Prowl 3.3EC, 3.5 pt/a). Water deficits (defined as difference between available water and field capacity of rooted soil, exceeding 4 inches) developed according to available soil water, crop growth, weather conditions, and experimental treatment (flood irrigation, using dikes to control runoff).
Sunflower crop development (leaf appearance and reproductive growth stage) was noted at weekly intervals. Canopy leaf area was measured weekly, using a Li-Cor 2000 canopy analyzer. Soil water was measured at weekly intervals by neutron thermalization. Crop stand (V8 and R9), yield components, and above-ground biomass were measured at physiological maturity from two 100 17 ft by 5 inch rows from each of four replicated plots. Plots were also machine-harvested when seed moisture was less than 12%. Seed was analyzed for moisture content, test weight, seed weight, and oil content.

Results
Irrigated yields in 2001 were 38% lower than yields in 2000 (Table 7). Yield reductions are attributed to a severe sunflower moth infestation, which reduced irrigated sunflower yields by 24% in Crop Performance Trials, 1 as well as insufficient irrigation amounts in 2001, due to faulty readings of soil water. Supplemental irrigation increased seed yields by 480 lbs/a each year, a lower response than expected. It is likely that insect pests limited yield potential of crop with adequate water supply. 2 Crop water use appears to be limited by available soil water when relative soil water (in the wettest soil layer) is less than 60% of water holding capacity (Figure 4). This result is consistent with other field observations, though the threshold relative water content may vary with soil conditions. Leaf area at flowering (R5) is correlated with relative soil water, observed during the mid-bud (R3) growth stage ( Figure 5). Thus, available soil water also appears to alter canopy development, though the effect may be delayed by two weeks.

Summary
This study was conducted to determine effects of planting date and maturity group in soybean productivity in rain-fed, semi-arid crop systems. Seven cultivars, representing maturity groups (MG) I, II, III, and IV were planted in four periods from late April through late June over three cropping seasons. Soybean yields ranged from 3.4 to 17.1 bu/a under drought conditions. With inconsistent results over years, a superior planting date or maturity group was not identified. Optimal rain-fed soybean yields, under drought conditions, occurred by planting a medium maturity (MG III) cultivar, i.e. 'Macon', in late April when soil moisture was adequate. When soil moisture was lacking, planting could be delayed until early June without apparent yield loss. Timing and precipitation amounts, in relation to crop development, likely contributed to yield variation.

Introduction
Soybean productivity in semi-arid regions can exceed 59 bu/a when rainfall is supplemented by irrigation. 1 However, less is known of yield potential in limited rainfall environments. Timing of rainfall, as well as amount, can affect productivity. Soybean maturity groups differ in days to flowering and maturity, as day length affects crop development. To test a range of growing conditions, four planting periods and seven cultivars representing four MG were evaluated. The objective was to determine seed yield and growth characteristics of soybean cultivars representing MG I, II, III, and IV, planted from late April through late June in rainfed, semi-arid cropping systems.

Procedures
The study was conducted at the Northwest Research-Extension Center, near Colby, Kansas on a Keith silt loam soil. The cultivars/MG included IA 1008 (I), IA 2021 (II), Turner (II), Macon (III), IA 3010 (III), K 1380 (IV), and KS 4694 (IV). Cultivar K 1380, an experimental line discontinued after 2001, was replaced with KS 4202 in 2002. Planting periods included late April, mid-May, early June, and late June. Soybean was planted (30 inch spacing, 7.4 seeds/ft, 130,000 seeds/a) with a JD 7300 planter on 10 x 50 ft plots in land fallowed after the previous crop. Seed was inoculated with Bradyrhizobium sp. Soil fertility was amended with 90 lb N/A and 30 lb P 2 O 5 /a. Herbicides and hand weeding controlled weeds.
Soybean crop development (vegetative and reproductive growth stage) was noted at weekly intervals. Canopy development was measured at flowering, using a LiCor 2000 canopy analyzer. Crop stand (V1 and R8), yield components, plant height, height of lowest pod, and above-ground biomass were measured from two 3.3-ft (1-m) rows from each of four replicate plots. Plots with uniform stand were machine-harvested 7 to 10 days after R8; the best stands of non-uniform plots were hand-harvested. Seed was analyzed for seed weight, oil content, crude protein, and germination fraction.

Results
Drought conditions limited soybean yields throughout the study period (Table 8). Timing of precipitation likely affected stand establishment, canopy development, seed set, and seed fill processes. Early planting resulted in highest yields in 2000, a year when stored soil water was high (Table 8). However, early planting resulted in lowest yields in 2002, when stored soil water was low and hot, dry summer conditions prevailed. Yield variation was high among cultivars, planting periods, and years. Each cultivar yielded both poorly and well among the planting periods and years evaluated. The MG III cultivar 'Macon' provided the numerically greatest yield, averaged over planting dates and years. However, the MG IV cultivar 'KS 4694' provided similar overall yields. The yield potential of cultivars representing MG I and MG II was somewhat limited; however, these cultivars yielded as well as longer-season cultivars, given timely water supply (e.g., late April 2000 and early June 2001 planting periods).
Results at this location indicate that rain-fed soybean yields under drought conditions are maximized by planting a medium maturity (MG III) cultivar, i.e. 'Macon', as soon as late April when soil moisture is adequate. When soil moisture was lacking, planting could be delayed until early June without apparent yield loss. Timing and amount of precipitation, in relation to crop development likely contributed to substantial variation in yield. The Kansas Soybean Commission Checkoff program provided support for this study.

Summary
Cold tolerance for seedling emergence and growth can improve sorghum grain production. Multiple traits, with independent association, and perhaps multiple loci appear to contribute to cold tolerance. Laboratory, greenhouse, and field studies were conducted to investigate contributions of male and female parents to cold tolerance and to compare growth of breeding lines under cool conditions. Earlier germination resulted from hybrids derived from a cold-tolerant male, relative to germination with a cold-susceptible male parent. The difference appears to result from the germinating seed's ability to accumulate heat units at cooler temperatures. Growth of two cold-tolerant breeding lines from the Highlands of Kenya was two times greater than growth of cold-susceptible lines 30 days after field-planting (April 20, 2001). Hybrids derived from a cold-susceptible male line had intermediate growth rates; analogous hybrids derived from the cold-tolerant male had similar or slightly lower growth rates.

Introduction
Cold tolerance for seedling emergence and growth can improve sorghum grain production by: C Increasing yield potential from an extended growing season C Providing stress avoidance by earlier development under more favorable rainfall regimes C Enabling expanded production zones into the semi-arid cool uplands i.e. central High Plains.
Rapid germination and vigorous growth of grain sorghum seedlings under cool (<15 o C) soil conditions is a significant cold-tolerant trait. Temperature sensitive processes in seedling establishment include germination, growth, and emergence. Heritable differences can be independent for each process. This independent inheritance may contribute to the difficulty of developing cold-tolerant sorghum cultivars.
Knowledge of breeding line characteristics provides incomplete knowledge of hybrid effects. The female seed parent contributes 100% genetic traits of the pericarp and embryonic cell cytoplasm, 67% of the endosperm, and 50% of the embryo. Tolerance traits of both male parent and seed parent can confer tolerance traits to progeny when crossed with a susceptible parent. But benefits of male tolerance may provide additional protection when crossed with a tolerant seed parent. Multiple traits, with independent association, and perhaps multiple loci, appear to contribute to cold tolerance. Laboratory, greenhouse, and field studies were conducted to investigate contributions of male and female parents to cold tolerance, and to compare growth of breeding lines under cool conditions.

Procedures
A germination study was conducted in growth chambers using hybrids of susceptible (TX 2737) and tolerant (SQR) male lines, crossed with susceptible (TxArg1), tolerant (Wheatland, Redlan), or intermediate (SA 3042) female lines. Both male breeding lines (self-pollinated) were included for reference. Seeds were incubated on moist filter paper in petri dishes at 12, 16, 20, or 24 o C. Observations included time to germination (radicle protrusion 1 mm beyond seed coat); time to radicle growth exceeding 5 mm and 10 mm, with associated coleoptile lengths; electrolyte leakage, as a measure of membrane stability; and endosperm utilization efficiency.
Seedling growth studies were conducted under greenhouse and field conditions using two sets of genetic material. One set was as described in the germination study above. The second set was selected from 37 cold tolerant lines, derived from the Kenya Highlands, in addition to tolerant and susceptible reference lines. The selected lines exhibited either highgermination or high-emergence rates at 10 o C in a previous screening trial. In the greenhouse study, pre-germinated seed was planted in a potting mix of 1:1:2 Keith silt loam:perlite:sand. Seedlings were harvested 10, 20, or 30 days after planting. Observations included seed viability, root length, coleoptile (and shoot) lengths, and dry weights of root and shoot (including coleoptile).
In the field study, seed was planted in a Keith silt loam soil on April 20, 2001 when soil temperature averaged 14 o C (5 o F) at 10 cm (4 inch) depth. Observations included emergence (three observation periods each week), shoot weight 30 days after planting, heading date, and maturity date. Comparisons of seedling growth among studies are based on cumulative growing degree days, using daily ambient temperature extremes, and limited by a minimum temperature of 8 o C (46.4 o F).

Results
Heat units and base temperature required for germination can be calculated from time to germination for seeds incubated with a range of constant temperature treatments. Figure 6 shows germination data for two hybrids involving a female line with intermediate cold tolerance (SA 3042) and male lines considered tolerant and susceptible to cold. The inverse of germination time (1/time) is plotted against incubation temperature. The inverse of germination time decreases with cooler temperatures, indicating more time is required for germination when seed is incubated at cooler temperatures.
When SQR is the male parent, the hybrid seed appears to start accumulating heat units when the temperature exceeds 7.3 o C; the corresponding base temperature for heat unit accumulation appears to be 10.1 o C when TX 2737 is the male parent. Thus, the SQR hybrid appears to accumulate heat units at cooler temperatures than the TX 2737 hybrid, resulting in earlier germination.
Seedling size and weight provide an integrative measure of growth and vigor. Figure 7 shows seedling biomass for selected lines and hybrids, observed in both greenhouse and field studies. The results are plotted in relation to cumulative growing degree days following planting. Change in seedling biomass is consistent with the exponential growth phase of the logistic equation commonly used to represent vegetative growth for annual plants. The two lines susceptible to cold, TX 430R and TX 2737, exhibit low growth rates under field conditions (data points at 280 o C-days, at 30 days after planting). In contrast, two tolerant lines from the Highlands of Kenya (IS11352 and IS 25527) exhibited growth two times greater under these field conditions. Hybrids derived from the TX 2737 male line had intermediate growth rates; analogous hybrids derived from the SQR male had similar or slightly lower growth rates.

Introduction
The Sandyland Experiment Field was established in 1952 to address the problems of dryland agriculture on the sandy soils of the Great Bend Prairie of SC Kansas. In 1966, an irrigated quarter was added to demonstrate how producers might use water resources more efficiently and determine proper management practices for, and adaptability of, crops under irrigation on sandy soils.
Research at the field has helped define adapted varieties/hybrids of wheat, soybeans, alfalfa, grain sorghum, cotton, and corn. As irrigated corn, soybean, wheat, and alfalfa production grew in importance, research determined proper management strategies for irrigation, fertilizer, pest control, and related cultural practices. Presently, research focuses on variety/hybrid evaluation, the evaluation of new pesticides for the area, the practicality of dryland crop rotations involving summer annual forages, corn nitrogen fertilizer requirements, and re-examining accepted cultural practices. Winter forage studies for cattle were initiated in 1999 and involved planting wheat, rye, and triticale. These studies were expanded in 2000.

Soil Description
Soil surface horizons range from Pratt, Carwile, and Naron loamy fine sands to Farnum, Naron, and Tabler fine sandy loams. Subsoils are much more varied, ranging from loamy fine sand to clay. These soils are productive under dryland conditions with intensive management and favorable precipitation patterns. Conservation tillage practices are essential for the long-term production and profitability of dryland summer row crops. Under irrigation, these soils are extremely productive and high quality corn, soybean, and alfalfa are important cash crops.

Weather Information
The growing season was characterized by hot conditions from mid-June through September. Conditions for the 2003 wheat crop were hampered by excessive rainfall in October (Table 1) and overall cooler than normal temperatures. Growing season length was slightly longer than the long-term average of 185 days by 3 days. Precipitation was under the long-term average of 26.1 inches (Table 1) by 2.2 inches. This number is somewhat deceiving as 52% of the year's precipitation was received in two months (June and October). Rainfall from January though March was 47% of normal; rainfall from April through September was 80% of normal, although the distribution was skewed with 36% occurring in June. From October through December subsoil moisture levels were helped with 7.6 inches of precipitation, 181% of normal. Wheat yields in 2002 were variable with many fields severely impacted by dry conditions from September 2001 through May 2002, which had only 52% of normal precipitation. The August moisture did save much of the grain sorghum crop and resulted in average yields. The moisture was too late to help much of the dryland corn and overall dryland corn yields were well below average.  St. John, 20-year average, 2001

Summary
Rye, wheat, and triticale pasture were evaluated in 2000, 2001, and 2002 for their ability to increase cattle weight from late fall through mid-spring. Large scale studies were conducted on two 80-acre sites divided into either 25-or 40acre pastures. Cattle at these sites were stocked at 1 head/acre with an average initial weights between 500 and 550 lb/head. At the Sandyland Experiment Field, small scale studies were conducted using the same winter cereals for forage but at higher stocking rates, ranging from 2 to 3 head/acre. Supplemental feeding, as necessary, included summer annual forage hay, prairie hay, and grain consisting of wheat mids and processed grain sorghum. Winter cereals were planted at 100 lb/acre in September of each year. Rye provided the best pasture in terms of cattle weight gain and needed the least supplemental feeding. Wheat was next in producing pounds of beef and triticale produced substantially less gain than either rye or wheat. Rye and wheat were more able to support increased stocking rates than triticale.

Introduction
Annually, forage in Kansas supports 1.5 million beef cows and calves, 0.8 million dairy cows, and 4-5 million yearling cattle. Cattle and the production of forage and grain for feed represent a significant portion of agricultural revenues in Kansas. Dryland grain production in the Sandyland service area is variable due to both soil type and climate. Typically, adequate moisture is available for good pre-flowering vegetative growth; however, available soil moisture, erratic rainfall, and high temperatures often severely impact grain yield. Wheat vegetative and early reproductive growth are normally good due to adequate rainfall and moderate temperatures. Wheat yield reduction is due to high temperatures during late grainfill that essentially halt grain development and kill the plant.
More efficient and consistent use can be made of available moisture if dryland producers focused on harvesting vegetative growth and relied less on grain production for income. Using summer annual forages and winter cereals as forage for hay and grazing connects to the market for which most of their production is already geared -cattle. These forages and systems integrating their use are well-adapted for cattle production, less expensive than traditional grain production, and decease risk.
Forage systems are not without negatives. If forages are grown for hay, producers must either invest in haying equipment or contract with custom hay operations. Forages used for pasture require investments in fencing, need available sources for watering livestock, and are labor and time intensive. Additionally, pasturing cattle properly requires intensive management. Finally, although risks are lessened as reliance on grain production is reduced, producers raising their own cattle are susceptible to fluctuations in the cattle market.
The primary objective of this study is to determine actual cattle weight gain on dryland winter cereal pasture and develop production systems/best management practices to optimize cattle production. Objective two, determine the practicality of a dryland winter cereal pasturesummer annual forage production system.

Procedures
All costs were the same each year for each pasture with the exception of seed costs. Cost per acre were $7 for rye seed, $10 for wheat, and $20 for triticale. Rye, wheat and triticale pastures were all treated identically with the exception of stocking rates during the 2001-2002 year.

Winter 1999-2000
The site was summer fallowed in 1999 after wheat harvest, prior to fall planting of winter cereals. Fertilization consisted of 100 lb/a 18-46-0 and 50 lb/a N broadcast as urea (46-0-0). Fertilizer was incorporated with the final tandem disking. Tillage consisted of one offset disking followed by two offset diskings. Tillage was accomplished by September 1. Four pastures (0.8 acre each) were established with wheat (Jagger), Rye (Amilo), triticale (Presto), and a 50/50 rye/triticale blend. Target seeding rate was 100 lb/acre with an actual rate of 105 lb/acre planted on September 23 using a hole drill and 10 inch rows. Heifers, two head per pasture, were turned out on December 4 on all pastures except the triticale, which was delayed until February 3. Cattle were supplemented with 2 lb/day grain and during snow cover with 230 lb/head/day of alfalfa hay. Heifers were weighed initially on December 4, February 1 and March 21.

Winter 2000-2001
The study was expanded in the winter of 2000-2001. At Sandyland three, 3-acre pastures were established following the 2000 wheat harvest on fine sandy loam soils. Tillage and fertilization were identical to 1999-2000 as was the stocking rate. Rye, wheat, and triticale, same varieties as in 1999-2000, were planted at 100 lb/acre on September 26. Cattle were weighed on November 29, January 4, February 5, March 16, April 19, and May 16.
Two 80-acre offsite locations were established. Each was split into three 25-acre pastures and treated and planted the same as the small scale Sandyland sites. One site is a loamy fine sand and the other a fine sandy loam. The only difference between off-site and Sandyland studies was stocking rate. Sandyland heifers were stocked at 0.6 acres/head while large scale studies were at 1.0 acres/head.
After heifers were removed in May, pastures at Sandyland were chisel plowed and disked twice. Fertilizer was applied prior to the final disking using 100 lb/acre 18-46-0 and 108 lb/acre urea (46-0-0). A BMR sorghum X Sudan hybrid was planted on June 12 at 18 lb/acre and harvested in mid-August to allow for a return to pasture in September.
The off-site loamy fine sand pastures were disked, fertilized and planted to NC+ Sweetleaf at 20 lb/acre in mid-June and harvested in Mid-August. The sandy loam was too wet to plant to a summer annual forage. Wheat, rye, and triticale regrowth were swathed and baled in late June. Crabgrass already present was allowed to grow until Mid-August and then swathed and baled.

Winter 2001-2002
After baling of supplemental summer annual forages, tillage and fertilization was the same as in 2000-2001. Wheat planted was again Jagger while triticale was stitched to Tricale 2+2, and the rye variety was not stated.
Dry conditions in late fall and early winter made it necessary to pasture cattle on corn stubble and supplement with hay. Pastures were not suitable for grazing for mid-April. Stocking rates were determined by qualitative examination of growth (height and degree of tillering). Stocking rates are described in Table 6. After cattle were removed, the ground was prepared as described in 2000-2002. Honey Sioux V sorghum x Sudan hybrid was seeded at 16 lb/acre in 10 inch rows in early June following rye, Jagger wheat and triticale. One Jagger wheat pasture was summer fallowed. The Betty wheat pasture was seeded to hybrid pearl millet at 12 lb/acre in 10 inch rows at the same time. Both summer annual forages were seeded on adjacent lots that were winter fallowed to allow comparison with sites that were pastured over the winter.

Results
The target date for seeding winter pastures was September 1 all three years. Heat combined with low soil moisture contents delayed planting each year until the end of September (Table 2). To maximize the period of cattle on pasture, November 1 is the desired date to turn cattle out. In 1999In -2000In and 2000In -2001  For all three years, cattle on rye pasture outperformed wheat and triticale (Tables 3, 5, 6). Except during 2000-2001, cattle on wheat performed slightly less than on rye and better than on triticale.
During 2000-2001, cattle performance was about equal on wheat and triticale (Table 5).
Conventional wisdom states that rye should outperform triticale late fall/early spring but weight gain for cattle on triticale will exceed rye and wheat late spring and provide for a longer pasture season. This was the case in 1999-2000 (Table 3). However, in 2000-2001 triticale outperformed rye late fall and lagged significantly behind rye during the entire spring period (Table  5). This data contradicts results from producers in NC and NW Kansas and clipping studies conducted at the KSU Agricultural Research Center at Hays. Possible reasons include the coarser texture of the soil used in this study, which has a lower water holding capacity. Secondly, clipping studies do not necessarily translate into actual cattle grazing results. Finally, from observing cattle grazing, cattle on the triticale pastures did not appear to graze the triticale as aggressively, even though good vegetative growth was present.
Stocking rates affected average daily gain in 2000-2001 (Table 4). Late fall/early winter gain was significantly less at Sandyland with 0.5 acres/head as opposed to the other two sites stocked at 1.11 acres/head. However, during spring grazing gain per head was slightly less at the higher stocking rate, but pound per acre gain was twice that of the conventional rate of approximately one head per acre. This was likely due to the relatively dry fall conditions which limited regrowth while spring conditions were excellent for pasture growth.
In 2001-2002, cattle were turned out on Betty wheat and, though results were not quite as good as Jagger wheat, cattle gain was much better than cattle on triticale (Table 6). It should be noted that this was spring grazing only and does not mean that Betty wheat is suitable for late fall/early winter pasture. Since the grazing period was quite brief, cattle stocking rates were successfully increased for the wheat and rye (Table 6). Rye, stocked at 0.3 acres/head, resulted in gains of 1.9 lb/head and 6.1 lb/acre/day. Jagger wheat pasture resulted in 4.5 lb/acre/day with Betty wheat producing 3.9 lb/acre/day. Triticale gains were much lower at 2.0 lb/acre/day and required much greater supplemental feeding to produce significantly less beef. Cattle placed on cornstalks during 2001-2002 maintained and in fact gained 0.60 lb/head/day (Table 6). This provides a viable option for producers needing pasture before winter cereal pasture is ready, providing supplemental hay and grain are practical.
Overall, rye produced the best gains not only per head but also allowed for higher stocking rates and seeding costs were low. Wheat was intermediate in performance per head and stocking rate, but still allowed for higher than normal rates. Triticale seeding costs were much higher, $20 per acre, weight gain was at best comparable to wheat but typically lower, and higher stocking rates were not practical.
Summer annual forage production, sorghum x Sudan hybrid and hybrid pearl millet, were severely affected by extreme heat and drought conditions during the 2001 growing season (Table  2). Pearl millet production was slightly higher than the sorghum x Sudan hybrid, 1.7 tons/acre vs. 1.5 tons/acre. Native crabgrass production was also affected by extreme heat and drought stress and averaged 0.25 tons/acre. Crabgrass and pearl millet hay contained few broadleaf weeds.
The sorghum x Sudan hybrid hay was approximately 20% Palmer amaranth.
Growing conditions for summer annual forage production were less stressful during the 2002 season. Pearl millet production following winter fallow was 2.2 tons/acre and slightly less following winter grazing at 2.2 tons/acre. Sorghum x Sudan hybrid hay production was also lower after winter grazing at 2.6 tons/acre vs. 2.8 tons/acre after winter fallow. Broadleaf weeds were nonexistent in the pearl millet hay and, while the sorghum x Sudan hybrid hay contained some Palmer amaranth, it was much less than during the 2001 season. This is likely the result of the forages competing more effectively during 2002. A demonstration plot examining the effect of planting date on Pearl millet and sorghum X Sudan hybrid hay production indicated two trends. Production was unaffected by planting date from June 1 through July 15. Although this is atypical, it is likely the result of precipitation patterns that allowed later planting to compete with earlier planting. Of greater interest is weed competition. Very few herbicides are available for weed control in common summer annual forages. Some weeds, such as crabgrass, do not negatively impact feed quality, while mature pigweed and sandbur decrease palatability and feed value. Weed density decreased dramatically as planting was delayed and the only real weed pressure after mid-June was crabgrass. Crabgrass should only present a problem under extreme heat and moisture stress. Table 2. Monthly precipitation totals, 1999, and long-term average. Sandyland Experiment Field. Month 1999-20002000-20012001 Long-term Average   Spring weight gain, lb/acre 5.04 a 2.52 b 2.38 a,b Within a row, means with a different letter superscript are significantly different at P<.05. * 6.0 acres (0.5 acres/heifer) # 80 acres (1.11 acres/heifer) @ 80 acres (1.11 acres/heifer)

Introduction
The South Central Kansas Experiment Field, Hutchinson was established in 1951 on the US Coast Guard Radio Receiving Station located southwest of Hutchinson. The first research data were collected with the harvest of 1952. Prior to this, data for the South Central area of Kansas were collected at three locations (Kingman, Wichita, and Hutchinson). The current South Central Field location is approximately 3/4 miles south and east of the old Hutchinson location on the Walter Peirce farm.
Research at the South Central Kansas Experiment Field is designed to help the area's agriculture develop to its full agronomic potential using sound environmental practices. The principal objective is achieved through investigations of fertilizer use, weed and insect control, tillage methods, seeding techniques, cover crop and crop rotation, variety improvement, and selection of hybrids and varieties adapted to the area. Experiments deal with problems related to production of wheat, grain and forage sorghum, oats, alfalfa, corn, soybean, rapeseed/canola, sunflower and soil tilth. Breeder and foundation seed of wheat and oat varieties are produced to improve seed stocks available to farmers. A large portion of the research program at the field is dedicated to wheat breeding and germplasm development.

Soil Description
A new soil survey was completed for Reno County and has renamed some of the soils on the Field. The new survey overlooks some of the soil types present in the older survey and it is felt that the descriptions of the soils as follows is more precise. The South Central Kansas Experiment Field has approximately 120 acres classified as nearly level to gently sloping Clark/Ost loams with calcareous subsoils. This soil requires adequate inputs of phosphate and nitrogen fertilizers for maximum crop production. The Clark soils are well drained and have good water-holding capacity. They are more calcareous at the surface and less clayey in the subsurface than the Ost. The Ost soils are shallower than the Clark, having an average surface layer of only 9 inches. Both soils are excellent for wheat and grain sorghum production. Large areas of these soils are found in southwest and southeast Reno County and in western Kingman County. The Clark soils are associated with the Ladysmith and Kaski soils common in Harvey County but are less clayey and contain more calcium carbonate. Approximately 30 acres of Ost Natrustolls Complex, with associated alkali slick spots, occur on the north edge of the Field. This soil requires special management and timely tillage, because it puddles when wet and forms a hard crust when dry. A 10-acre depression on the south edge of the Field is a Tabler-Natrustolls Complex (Tabler slick spot complex). This area is unsuited for cultivated crop production and has been seeded to switchgrass. Small pockets of the Tabler-Natrustolls are found throughout the Field.

2001-2002 Weather Information
In 2000 the U.S. Department of Commerce National Oceanic and Atmospheric Administration National Weather Service rain gage (Hutchinson 10 SW 14-3930-8) measured 33.4 inches of precipitation, 3.4 inches above the 30-year (most recent) average of 30.0 inches. The year 2001 proved to be quite different from the previous 5 years in that the total precipitation for the year was below normal. However, it should be noted that the normal has been increasing in the past few years. The first 2 months of the year and September were above normal. Precipitation for the year totaled only 22.96 inches, 7.01 inches below the 30-year average. Even with the below normal precipitation, rainfall was recorded in every month of the year. The lack of moisture for 2001 started in March continued into mid-September. Precipitation for 2002 ended above normal (0.95) even though most months reported below normal precipitation. There were only four months where above normal precipitation was recorded (January, June, August, and October; Table 1).  crop year started out with good rains in mid-September and early October. The fall planting of wheat and canola went in with good soil moisture. Rainfall after early October was limited and the wheat and canola were stressed during the winter months. Winter temperatures were above normal which allowed the wheat to continue to grow and use the limited soil moisture. Timely rains in April and May had the wheat crop looking good. Three major rainfall events in June put the precipitation for that month well above normal. The following months alternated from below normal to above normal (Table 1). Two precipitation events (June 15 and August 12) are important in that they caused considerable damage to crops on the South Central Field and the surrounding area. The June 15 storm produced high winds and hail that shattered a large portion of the wheat and stripped the leaves off the summer crops that had emerged. The 2003 year started out dry as well.
The summer annuals (grain sorghum, sunflower, and soybean) that emerged or were planted after the June hail benefitted from the late rains. But these crops were then damaged by high winds in the August 12 storm. A frost-free growing season of 200 days (April 5 -October 21, 2002) was recorded. This is 17 day less than the average frost-free season of 183 days (April 19 -October 17).

Summary
The predominant cropping systems in South Central Kansas have been continuous wheat and wheat-grain sorghum-fallow. With continuous wheat, tillage is preformed to control diseases and weeds. In the wheat-sorghum-fallow system only two crops are produced every three years. Other crops (corn, soybean, sunflower, winter cover crops and canola) can be placed in the above cropping systems. To determine how winter wheat and alternative crop yields are affected by these alternative cropping systems, winter wheat was planted in rotations following the alternative crops. Yields were compared to continuous winter wheat under conventional (CT) and no-till (NT) practices. Initially, the CT continuous wheat yields were greater then those from the other systems. However, over time, wheat yields following soybean have increased, reflecting the effects of reduced weed and disease pressure and increased soil nitrogen. However, CT continuous winter wheat out yields NT winter wheat regardless of the previous crop.

Introduction
In South Central Kansas, continuous hard red winter wheat and winter wheat-grain sorghumfallow are the predominate cropping systems. The summer-fallow period following sorghum is required because the sorghum crop is harvested in late fall, after the optimum planting date for wheat in this region. Average annual rainfall is 29 in./yr, with 60 to 70% occurring between March and July. Therefore, soil moisture is often insufficient for optimum wheat growth in the fall. No-tillage (NT) systems can increase soil moisture by increasing infiltration and decreasing evaporation. However, higher grain yields have not always been observed in association with increased soil water in NT. Cropping systems with winter wheat following several alternative crops would provide improved weed control through additional herbicide options and reduced disease incidence by interrupting disease cycles, as well as allow producers several options under the 1995 Farm Bill. However, fertilizer nitrogen (N) requirements for many crops is often greater under NT than CT.
Increased immobilization and denitrification of inorganic soil N and decreased mineralization of organic soil N have been related to the increased N requirements under NT. Therefore, evaluation of N rates on hard red winter wheat in continuous wheat and in cropping systems involving "alternative" crops for the area have been evaluated at the South Central Field. The continuous winter wheat study was established in 1979 and was restructured to include a tillage factor in 1987. The first of the alternative cropping systems where wheat follows short season corn was established in 1986 and modified in 1996 to a wheat-cover crop-grain sorghum rotation. The second (established in 1990) has winter wheat following soybean. Both cropping systems use NT seeding into the previous crop's residue. All three systems have the same N rate treatments.

Procedures
The research was conducted at the KSU South Central Experiment Field, Hutchinson. Soil was an Ost loam. The sites had been in wheat previous to the start of the experimental cropping systems. The study was replicated five times using a randomized block design with a split plot arrangement. The main plot was crop and the subplot six N levels (0, 25, 50, 75, 100, and 125 lbs/a). Nitrogen treatments were broadcast ap-125 plied as NH 4 NO 3 prior to planting. Phosphate was applied in the row at planting. All crops were produced each year of the study. Crops are planted at the normal time for the area. Plots are harvested at maturity to determine grain yield, moisture, and test weight.

Continuous Wheat
These plots were established in 1979. The conventional tillage treatments are plowed immediately after harvest then worked with a disk as necessary to control weed growth. The fertilizer rates are applied with a Barber metered screw spreader prior to the last tillage (field cultivation) on the CT and seeding of the NT plots. The plots are cross seeded in mid-October to winter wheat. As a result of an infestation of cheat in the 1993 crop, the plots were planted to oats in the spring of 1994. Fertility rates were maintained and the oats were harvested in July. Winter wheat has been planted in mid-October each year in the plots since the fall of 1994. New herbicides have aided in the control of cheat in the no-till treatments.

Wheat after Corn/Grain Sorghum Fallow
In this cropping system, winter wheat was planted after a short-season corn had been harvested in late August to early September. This early harvest of short-season corn allows the soil profile water to be recharged (by normal late summer and early fall rains) prior to planting of winter wheat in mid-October. Fertilizer rates are applied with the Barber metered screw spreader in the same manner as for the continuous wheat. In 1996, the corn crop in this rotation was dropped and three legumes (winter pea, hairy vetch, and yellow sweet clover) were added as winter cover crops. Thus, the rotation, became a wheat-cover crop-grain sorghum-fallow rotation. The cover crops replaced the 25, 75, and 125 N treatments in the grain sorghum portion of the rotation. Yield data can be found in Field Research 2000, KSU Report of Progress 854.

Wheat after Soybean
Winter wheat is planted after soybean has been harvested in early to mid September in this cropping system. As with the continuous wheat plots, these plots are planted to winter wheat in mid-October. Fertilizer rates are applied with the Barber metered screw spreader in the same manner as for the continuous wheat. Since 1999 a group III soybean has been used. In 1999, this delayed harvest to October 5 effectively eliminating the potential recharge time as the wheat was planted October 12. After a wet October, the winter was extremely dry. This, coupled with the late soybean harvest, caused reduced yield in this rotation. In 2002, the wheat crop looked excellent until the June hail that severely shattered the grain. The effect of N rate on maturity can be seen in the yields as affected by hail.

Wheat after Grain Sorghum in a Cover Crop/Fallow-Grain Sorghum-Wheat
Winter wheat is planted into grain sorghum stubble harvested the previous fall. Thus, the soil profile water has had 11 months to be recharged prior to planting of winter wheat in mid-October. Nitrogen fertilizer is applied at a uniform rate of 75 lbs/a with the Barber metered screw spreader in the same manner as for the continuous wheat.
Winter wheat is also planted after canola and sunflower to evaluate the effects of these two crops on yield of winter wheat. Uniform nitrogen fertility is used, therefore, the data is not presented. The yields for wheat after these two crops is comparable to wheat after soybean.

Continuous Wheat
Continuous winter wheat grain yield data from the plots are summarized by tillage and N rate in Table 3. Data for years prior to 1996 can be found in Field Research 2000, KSU Report of Progress 854. Conditions in 1996 and 1997 proved to be 126 excellent for winter wheat production in spite of the dry fall of 1995 and the late spring freezes in both years. Excellent moisture and temperatures during the grain filling period resulted in decreased grain yield differences between the conventional and no-till treatments within N rates. Conditions in the springs of 1998 and 1999 were excellent for grain filling in wheat. However, the differences in yield between conventional and notill wheat still expressed themselves (Table 3). In 2000 the differences were wider up to the 100 lb/a N rate. At that point the differences were similar to those of previous years. The wet winter and late spring of the 2001 harvest year allowed for excellent tillering and grain fill. However, the excess dry matter produced in the 100 and 125 lb/a N rates resulted in decreased grain yields for those treatments. Yields for 2002 were severely affected by the June hail.

Wheat after Soybean
Wheat yields after soybean also reflect the differences in N-rate. However, when comparing the wheat yields from this cropping system with those where wheat followed corn, the effects of residual N from soybean production in the previous year can be seen. This is especially true for the 0 to 75 lb/a N rates in 1993 and the 0 to 125 lb/a rate in 1994 (Table 4). Yields in 1995 reflect the added N from the previous soybean crop with yield by N-rate increases similar to those of 1994. The 1996 yields with spring wheat reflect a lack of response to nitrogen fertilizer for this crop. Yields for 1997 and 1998 both show a leveling off after the first four increments of N. As with the wheat in the other rotations in 1999, the ideal moisture and temperature conditions allowed the wheat yields after soybean to express the differences in N rate up to the 100 lb/a rate. In the past, those differences stopped at the 75 lb/a N treatment. When compared to the yields in the continuous wheat the rotational wheat is starting to reflect the presence of the third crop (grain sorghum) in the rotation. Wheat yields were lower in 2000 than in 1999. This is attributed to the lack of timely moisture in April and May and the hot days at the end of May. This heat caused the plants to mature early and also caused low test weights. The effects of the June hail storm are reflected in the 2002 yield data. As the rotation continues to cycle, the differences at each N rate will probably stabilize after four to five cycles, with a potential to reduce fertilizer N applications by 25 to 50 lbs/a where wheat follows soybean.

Wheat after Grain Sorghum/Cover Crop
The first year that wheat was harvested after a cover crop-grain sorghum planting was 1997. Data for the 1997-2000 wheat yields are in Table  5. Over these 4 years there does not appear to be a definite effect of the cover crop (CC) on yield. This is most likely due to the variance in CC growth within a given year. In years like 1998 and 1999, where sufficient moisture and warm winter temperatures produced good CC growth, the additional N from the CC appears to carry through to the wheat yields. With the fallow period after the sorghum in this rotation, the wheat crop has a moisture advantage over wheat after soybean. The hail in June of 2002 caused considerable shattering and equalized the grain yields to some extent.

Other Observations
Nitrogen application significantly increased grain N contents in all crops. Grain phosphate levels did not seem to be affected by increased N rate.
Loss of the wheat crop after corn can occur in years when fall and winter moisture is limited. This loss has not occurred in continuous winter wheat regardless of tillage or in the wheat after soybean. Corn will have the potential to produce grain in favorable years (cool and moist) and silage in non-favorable years (hot and dry). In extremely dry summers, extremely low grain sorghum yields can occur. The major weed control problem in the wheat after corn system is with the grasses. This was expected, and work is being done to determine the best herbicides and time of application to control grasses.

Soybean and Grain Sorghum in Rotations
Soybean was added to intensify the cropping system in the South Central area of Kansas. It also has the ability, being a legume, to add nitrogen to the soil system. For this reason the nitrogen rates are not applied during the time when soybean is planted in the plots for the rotation. This gives the following crops the opportunity to utilize the added N and to check the yields against the yields for the crop in other production systems. Yield data for the soybean following grain sorghum in the rotation are given in Table 6. Soybean yields are more affected by weather for a given year than by the previous crop. In 3 out of 5 years there was no effect of N rate that was applied to the wheat and grain sorghum crops in the rotation. In the 2 years that N application rate did affect yield it was only at the lower N rates. This effect was seen in other crops. Yield data for the grain sorghum after wheat in the soybean-wheat-grain sorghum rotation is in Table 7. As with soybean, weather is the main factor affecting yield. It can also be seen that the addition of a cash crop (soybean),thus intensifying the rotation (cropping system) will reduce the yield of grain sorghum in the rotation soybean-wheat-grain sorghum vs wheat-cover crop-grain sorghum. More uniform yields are obtained in the soybean-wheat-grain sorghum rotation (Table 8) than in the wheat-cover cropgrain sorghum rotation (Table 7).
It is hoped that these rotations will be continued after personnel are removed from the Field and it becomes a satellite Field. Other systems studies at the Field are: wheat-cover crop (winter pea)-grain sorghum rotation with N rates (data presented in Report of Progress 854, 2000), a date of planting, date of termination cover crop rotation with small grains (oat)-grain sorghum.     -Rate 1991-Rate 1992-Rate 1993-Rate 1994-Rate 1995-Rate 1996-Rate 1 1997-Rate 1998-Rate 1999-Rate 2000-Rate 2001-Rate 2002 lb/a bu/a  13 7 * Unless two yields in the same column differ by at least the least significant difference, (LSD) little confidence can be in one being greater than the other. 1. N rates are not applied to the soybean plots in the rotation.

Summary
The effects of the cover crop were most likely not expressed in the first year (1996) grain sorghum harvest (Table 9). Limited growth of the cover crop (winter peas) due to weather conditions produced limited amounts of organic nitrogen. Therefore, the effects of the cover crop when compared to fertilizer N were limited and varied. The wheat crop for 1998 was harvested in June. The winter pea plots were then planted and terminated the following spring prior to the planting of the 1999 grain sorghum plots. The N rate treatments were applied and the grain sorghum  Table 9.

Introduction
There has been a renewed interest in the use of winter cover crops as a means of soil and water conservation, a substitute for commercial fertilizer, and for maintenance of soil quality. One of the winter cover crops that may be a good candidate is winter peas. Winter peas are established in the fall, over-winter, produce sufficient spring foliage, and are returned to the soil prior to planting of a summer annual. Winter peas are a legume, meaning there is a potential for adding nitrogen to the soil system. With this in mind, research projects were established at the South Central Experiment Field to evaluate the effect of winter peas and their ability to supply N to the succeeding grain sorghum crop when compared to commercial fertilizer N in a winter wheat-winter pea-grain sorghum rotation.

Procedures
The soil in the experimental area is an Ost loam. The site had been in wheat prior to starting the cover crop cropping system. The study used a randomized block design and was replicated four times. Cover crop treatments consisted of fall planted winter peas with projected termination dates in April and May, and no cover crop (fallow). The winter peas are planted into wheat stubble in early September at a rate of 35 lb/a in 10-inch rows with a double disk opener grain drill. Prior to termination of the cover crop, above ground biomass samples are taken from a 1-m 2 area. These samples are used to determine forage yield (winter pea and other), and forage nitrogen and phosphate content for the winter pea portion. Fertilizer treatments are four fertilizer N levels (0, 30, 60, and 90 lb/a). Nitrogen treatments are broadcast applied as NH 4 NO 3 (34-0-0) prior to planting of grain sorghum. Phosphate is applied at a rate of 40 lbs P 2 O 5 in the row at planting. Grain sorghum plots are harvested to determine grain yield, moisture, test weight, and grain nitrogen and phosphate content. The sorghum plots are fallowed until the plot area is planted to wheat in the fall of the following year. The fertilizer treatments are also applied prior to planting of wheat.

Winter Pea/Grain Sorghum
Winter pea cover crop and grain sorghum results were summarized in the Field Research 2000 Report of Progress 854, pages 139-142. The grain sorghum yields were similar to the wheat yields in the long term N rate study. The first increment of N resulted in the greatest change in yield and the yields tended to peak at the 60 lb/a treatment regardless of the presence or lack of winter peas.
Grain sorghum yields for 2002 are presented in Table 9. These yields reflect the later planting date (June 22). The growing season in 2002 favored the later planted summer crops. These emerged after the June 15 hail storm and were not as mature for the August wind storm, thus they had less lodging and stock damage resulting in less secondary tillering and sucker heads. This allowed the main head to fill and produce a quality grain.

Winter Wheat
The fall of 2000 was wet, this after a very hot and dry August and September. Thus, the planting of wheat was delayed until November 24, 2000. Along with the wet fall, temperatures were also warm allowing the wheat to tiller into late December. January and February both had above normal precipitation which carried the wheat through a dry March. April, May and June were slightly below normal in precipitation and temperature. Wheat plots were harvested June 29, 2001.
Wheat yields were reported in Field Research 2002 (KSU Report of Progress 893, pg. 117) and data are not presented in this report. Wheat yields reflect the winter pea treatments as well as the reduced yields in the grain sorghum for the no-pea treatment plots. Test weight of the grain was not affected by pea or fertilizer treatment but was influenced most by rainfall at harvest time. This was also true for the percent nitrogen in the seed at harvest. Weed pressure is a particular concern with this rotation. The April termination pea plus 90 lb/a N treatment had significantly more weeds than any of the other treatments. Except for this treatment there were no differences noted for weed pressure.
As this rotation continues and the soil system adjusts it will reveal the true effects of the winter cover crop in the rotation. It is important to remember that in the dry (normal) years the soil water (precipitation) during the growing season most likely will not be as favorable as it was in 1999 and the water use by the cover crop will be the main influence on the yield of succeeding crop.

Introduction
Kansas State University Department of Agronomy has been involved in research in the south central region of Kansas for several decades. In 1999 the department began conducting research at the Wellington Area Test Farm. This is a 50-acre block owned by the First National Bank of Wellington. At the same time the department started placing research plots on farmer-owned land south of Argonia. Soils at the Wellington location consist of Bethany silt loam (Bb). These soils have a 1 to 3 percent slope, are well drained, but slowly permeable soils formed on old alluvium and loess. Other Bethany silt loam (Ba) soils on this location are similar to the Bb soil but have slopes of 0 to 1 percent. The other soil on the Wellington site is a Tabler silty clay loam (Ta) 0 to 1 percent slope. These soils are moderately well drained, but very slowly permeable, making them less than ideal for research. Soils at the Argonia locations are primally Bethany silt loams.
Research at Wellington and Argonia locations consists of variety tests with corn, grain sorghum, soybean, and cotton. Other studies include a soybean date of planting by maturity group study; a study of grain sorghum planting rate; and an evaluation of cotton herbicide and date of planting.

Summary
Four soybean varieties each from a different maturity group were planted at four dates in both Sumner County and at the South Central Field, Hutchinson. Averaged over groups, yields were highest for group II and III varieties for late April and early May planting dates in 1999 and 2000. Due to the extreme temperatures recorded in July 2001, the late June and July planting dates had higher yields than the early plantings. The 2002 date of planting study at Argonia was lost due to adverse weather conditions and poor weed control. At Hutchinson, the first two planting dates were severely affected by hail on June 15. This resulted in soybean from these planting dates maturing after the third planting date.

Introduction
The planting window for soybeans in the south central region of Kansas is quite wide and the large selection of varieties in various maturity groups can increase that window. If growing conditions are favorable, early planting of an early maturing (group II) bean can produce yields that exceed those of late planted beans regardless of their maturity group. Thus, selection of maturity group by planting date can allow the farmer considerable flexibility in scheduling spring planting of various crops. Several factors influence the selection of maturity group and variety, including soil type and moisture, potential rainfall and the possibility of a killing freeze in the fall before the crop is mature. The objective of this study was to evaluate soybean from different maturity groups planted across a range of dates.
This study was funded in part by the Kansas Soybean Commission.

Procedures
Plots were established at locations throughout Kansas. Experiments reported here were conducted at the South Central Field, Hutchinson in all four years. In Sumner County they were conducted on the Wellington Area Test Farm in 1999 and on land belonging to Jeff Tracy in 2000, and Mark Tracy in 2001and 2002, both sites are located south of Argonia. Varieties planted were Midland 8280 (II), Macon (III), Midland 8410 (IV), and Pioneer (V). Seeding rate was 160,000 plants/a in 30-inch rows. Planting dates for year by location are given in Table 10. At seeding plots received 16 lb/a N and 40 lb/a P 2 O 5 in a 2 by 2 placement. At maturity the center 2 rows (30 ft x 5 ft) were harvested for yield. All treatments were replicated 4 times at all locations. The 2002 plantings at Argonia were lost to wet conditions that resulted in poor weed control.

Results
Yield data by year, location, maturity group, and planting date are given in Table 10. In 1999 and 2000 the early planted group II beans had higher yields than the other maturity groups. At later planting dates (June and July) the later maturity groups started to narrow the yield gap between the early and late groups. At Argonia in 2000 the June 8 and July 5 beans did not mature before fall rains set in and continued until such time that the beans for these two planting dates were frozen and shattered to the point that a meaningful harvest was unattainable. The July 6, 2001 planting at Hutchinson did not survive the extreme heat and dry weather of July.
This same heat hit the Argonia location but that location received approximately 5.25 inches of rainfall during the same period. At the Argonia location the rainfall and heat caused a reversal of the yields observed the previous years. In 2001 at Argonia, late planted beans had higher yields, as did the late maturity groups (Table 10). Results from the 2002 Hutchinson location reflect hail damage and delayed maturity for first two planting dates.

Summary
A study was conducted under dryland and irrigated conditions to evaluate three row spacing configurations (30 inch, 20 inch, and twin row) at two plant density levels. Low corn yields as a result of high temperature and drought stress resulted in few differences between the row spacings or the plant density treatments at three of the four locations. At the lowest yielding location, the 30 inch rows produced higher yields than the other two row spacing treatments.

Introduction
Corn row spacing and configurations continue to be of interest in Kansas. Recently, the concept of twin row configurations has gained new interest as more precise seeding methods have been developed.
Twin rows configuration consists of two rows planted close together (7.5 inch) and centered on a standard 30 inch spacing. This configuration allows for some row crop equipment to be used, especially standard corn harvesting equipment. Previous narrow row corn research indicated that in most parts of Kansas, row spacing narrower than 30 inch will not consistently increase corn yields.

Procedures
Three row spacing configurations were tested under dryland at Manhattan, KS on a Reading silt loam; at Belleville, KS on a Crete silt loam; at Powhattan, KS on a Grundy silt loam; and under irrigation at Silver Lake, KS on a Eudora silt loam. The row spacing configurations consisted of 30 inch, 20 inch and twin row. The twin row configuration has two rows that are spaced 7.5 in. apart, each set of twin rows are spaced 30 in. apart. All plots were planted with John Deere 71-Flex planter units mounted on a two-bar planter. This configuration allowed for all possible row spacings to be planted in one pass through each plot by simply moving individual planter units to the appropriate location for each configuration. A randomized complete block design with four replications was used at each location. The

Results
Corn yields were lower than expected in 2002 due to extreme heat and dry conditions throughout late June and the entire month of July. Corn yields averaged below 100 bu/a at all locations and as a result, no differences between row spacings were found at Manhattan and Powhattan (Table 1). Damage to the overhead irrigation systems at Silver Lake on June 9 delayed initial irrigation and significantly reduced yields. Despite extremely low yields (30 bu/a) at Belleville, 30 inch rows produced higher yields than the 20 inch and paired rows. This is consistent with results found in row spacing experiments conducted in 1997 at the same locations.

Introduction
The Kansas growing season is relatively short for cotton, with average growing degree-day (GDD 60 ) accumulations ranging from 2075 to 2475 in the cotton growing regions of the state. Acreage has bloomed from approximately 2,000 harvested in 1996 to over 60,000 acres harvested in 2002, with plans to plant nearly 100,000 acres in 2003. Three gins are now operating in Kansas with a fourth planned.
Results from a current study have indicated that the cotton planted between May 1 and June 15 in central Kansas will usually produce yields adequate to cover all inputs and costs. Yield levels of different planting dates are greatly influenced by the amounts and timeliness of heat and rainfall received, especially from fruiting to fiber maturity.
Thunderstorms with accompanying hail can cause damage to cotton fields ranging from yield losses to field abandonment. The objective of this research was to evaluate the response of cotton at different stages of development to defoliation by hail.

Procedures
The response of cotton to date(s) of planting (DOP) was evaluated at the Kansas State University South Central Experiment Field near Hutchinson, KS, in the 2000 and 2001 growing seasons. The final year of the study was to be 2002. Six-row plots were planted in 30-in. rows on May 2 (DOP 1), May 28 (DOP 2), June 10 (DOP3), June 21 (DOP 4) and July 10 (DOP 5), 2002. Approximately 70,000 seeds/acre were dropped. The cotton variety planted was Delta and Pine Land 'PM 2280 BG/RR'. A starter band containing 35 lb/acre of actual nitrogen (N) and phosphorus (P) was applied as liquid over the row. A preemerge herbicide combination of 1.0 pt/acre Dual II Magnum® plus 0.6 oz/acre Staple® was applied to plots immediately after planting. Roundup Ultra Max® at 26 oz/acre was applied postemergence when cotton seedlings reached the four leaf stage, and hand weeding was used for late season weed control. The center two rows of each plot were machine harvested November 19 and yields were calculated according to .

Results
Prior to the hailstorm that altered the original objectives of this study, precipitation received ( Fig. 1) was at or above the long-term average (LTA) and GDD 60 (Fig. 2) below the LTA. Prior to the hailstorm of June 15, DOP 1 and DOP 2 cotton had seven and three fully developed leaves, respectively. Following the hailstorm, all DOP 1 and DOP 2 cotton was 95-100% defoliated with stems broken and bruised. DOP 3 cotton plants had hypocotyls just breaking the soil surface or the cotyledons had just unfurled. DOP 1 cotton populations were reduced by 50% as compared to populations in the replant (DOP 4), yet still had more surviving plants than those of DOP 2 and DOP 3. The storm had similar effects, as noted by remaining plant populations, on the less developed seedlings of DOP 2 and DOP 3.
Beginning bloom dates were approximately one week later than what was expected from previous years' results. When cotton was in full bloom and fiber development stages, timely, useable precipitation amounts were received. The number of bolls per acre is strong evidence of the timely climatic events. No differences in boll counts existed between the first three DOP regardless of the fact that differences in plant populations were reported. These boll numbers resulted in exceptional cotton yields (Table 2), similar to trends reported by Morrow and Krieg (1990). Though bolls per acre were similar, yields from DOP 2 cotton were greater than those of DOP 1. The DOP 1 plants were already beginning to develop fruiting nodes when injured 141 and had to regenerate photosynthetic area to be able to regenerate new fruiting branches, potentially slowing development of the plants. In addition, the stems that survived were injured, as evidenced by excessive scarring and branching, perhaps restricting nutrient and water flow to the bolls which resulted in reduced boll weights when compared to DOP 2 plants. DOP 1 yields were similar to those from DOP 3, which, according to Peng et al. (1989), would be the result of lighter bolls from later plantings.

Conclusions
These results indicate that when timely and adequate precipitation events, coupled with LTA levels of GDD 60 , accumulate after a severe weather event, surviving cotton populations can still produce adequate yields. Results should be interpreted with caution since they represent data from only one year at one site.

Introduction
Kansas farmers have increased cotton plantings from about 2,000 acres in 1996 to over 60,000 acres in 2002. Three gins are now operating in counties bordering Oklahoma. Custom operators do the bulk of the harvesting, and occasionally harvest is delayed by weather events and the availability of equipment. Ray and Minton (1973) reported lint yield losses of up to 18, 12 and 6.5 pounds per week if cotton was left in the field up to 1, 4 or 11 weeks, respectively, after the crop reached harvestable condition. Micronaire was not significantly affected, but fiber length, strength and reflectance were all reduced by extended field exposure. Yellowness decreased as exposure to the elements lengthened.  reported similar negative effects on fiber quality as field exposure time increased. Based on the USDA loan value, these reductions in quality translated into approximate losses of $0.06/lb (Kelley et al.) in 2002 or up to $9.50/acre (Ray and Minton) in the first week of harvest in 1973. The objective of this study was to quantify potential cotton yield, quality and income losses due to delayed harvest.

Procedures
Date(s) of harvest (DOH) effects on machineharvested cotton was evaluated at the South Central Experiment Field near Hutchinson, KS, in the 2001 and 2002 growing seasons. Four-row plots were planted in 30-in. rows on June 13, 2001, andMay 28, 2002. Approximately 66,200 seeds/ acre were dropped both years. The cotton variety planted was Delta and Pine Land 'PM2156RR' which is commonly grown in Kansas. This variety also has one of the lowest storm-proof ratings of cotton varieties commonly grown in Kansas, therefore representing a worstcase scenario for weather related losses. A total of 50 lb/acre nitrogen (N) was applied each year to the plot area. A preemerge herbicide combination was applied after planting, Roundup Ultra Max® at 26 oz/acre was applied post emergence and plots were hand weeded for late season weed control. Harvest aids were applied each year to the plots. The center two rows of each plot were machine harvested and yields were calculated similar to the methodology of . Harvest dates (Table 1) were set at 14-day intervals, weather dependant, or as soon as possible after significant precipitation events. Precipitation between harvests is summarized in Table 1. A sub-sample was taken from each plot, ginned and the fiber submitted to the International Textile Center at Texas Tech Univ., Lubbock, TX, for fiber quality analysis. Lint values were calculated using the Cotton Loan Value calculator developed by Kelley at Texas A&M (2000).

2001
Consistent, untimely rainfall in 2001 delayed planting until June 13. Once planted, the crop emerged rapidly and uniformly.
In spite of timely rains the crop was heat and moisture stressed throughout the fruiting and filling periods. Yields (Table 3 and Figure 3) were unaffected for the first three harvest dates, but did decline between DOH 3 and 4. No significant yield losses were recorded between DOH 4 and 5 even though a sleet storm and a heavy, wet snow storm occurred. In the 26 days between DOH 3 and DOH 4 only a trace of precipitation fell, but high winds (wind speeds of at least 15 mph) were recorded 20 of those days and may be the cause for the lint loss. The fiber qualities affected were Rd and +b (Table 4), which increased and decreased, respectively. The effect of delayed harvest on lint yields was similar to results reported by Ray and Minton (1973).  however, reported that field weathering significantly reduced staple length, uniformity and strength on the High Plains of Texas. In our study, fiber strength was not significantly reduced, but was numerically reduced by 15-25 points after DOH 1 (Table 4), according to the Plains Cotton Cooperative Association loan rate chart. The USDA loan value fluctuated only about $0.01 per lb through the harvest season (Table 5). The value of lint lost from weathering was from $28.42-$39.95 per acre from the first three DOH, to DOH 4. Delaying harvest another 43 days cost reduced revenue another $9.26 per acre. The lint and monetary loss trends are similar to those reported by Ray and Minton (1973). When value was lost, the biggest loss was the first loss. The magnitude of yield and revenue reductions declined with delayed harvest(s) after the first big loss.

2002
Excessive precipitation and cool temperatures resulted in slow emergence and growth of seedlings. In addition, a hailstorm hit the plots at the two to three leaf stages. Final plant stands averaged about 31,700 plants/acre, barely half the targeted populations. However, above normal HU accumulation and timely precipitation resulted in exceptional lint yields (Figure 3). Gross returns from the 2002 crop (Table 5) were higher than those of 2001. Lint yields trended up in the 8 days between DOH 1 and 2, probably as the result of late maturing bolls opening. The $36.60 per acre increase in value between harvest dates is certainly appealing. The supposition that DOH 2 yields were supplemented by later maturing bolls is supported by the corresponding drop in micronaire (Table 4) as harvest was delayed. A wet snow fell between DOH 2 and DOH 3 and contributed to 33% harvested lint reductions. No differences existed between DOH 3 and DOH 4 in spite of an intense rainstorm. Two wet snows fell between DOH 4 and DOH 5, but lint yields were not adversely affected. The trend of the first significant harvest losses resulting from the first weather event and then lower to no losses from subsequent weathering events was consistent. Ray and Minton (1973) reported similar results. Only the first two DOH fiber quality characteristics will be discussed. The favorable weather during fiber development, vs that in 2001, is obvious (  (Ray and Minton,1973;, who found no change in micronaire after field weathering. Both Ray and Minton (1973) and  reported reduced fiber length and strength as a result of field weathering, but neither of those trends was measured in the two harvests of 2002.

Conclusions
When harvest date is delayed past optimum, lint yields and gross income will be significantly reduced. The higher the yield levels, the greater the magnitude of yield loss from weathering. The first major weather event had the greatest impact on yield losses with subsequent weather contributing little to the overall yield reductions. Kansas harvest season precipitation amounts were less than those in studies of other investigators, which may have resulted in "less" field weathering of fiber grown in Kansas. Consequently, fiber quality of Kansas cotton has not been reduced when harvest was delayed, contrary to the findings from Texas.

Summary
Sunflower yields under irrigation have been erratic and difficult to predict. This research was implemented to examine sunflower yield under limited or partial season irrigation to determine yield potential and economic yield. In 2001, oil type sunflowers were grown on a cooperator's center pivot irrigated field. The dryland control replicates produced 1510 lb/a, while the irrigated treatment produced 2800 lb/a with 8.3 inches of irrigation. In 2002, yields ranged from 708 lb/a dryland to over 2500 lb/a with 7.7 inches of irrigation. The 2002 yields were decreased by uncontrolled insect pressure and bird and deer predation. When yields were adjusted to remove insect damage and predation effects, the range was from 1259 dryland to over 2900 lb/a with 7.7 inches of irrigation. When stalks of the two hybrids were split and examined for insect larvae, a standard height hybrid had spotted stem weevil larvae in 50 out of 50 stalks, while a short statured hybrid had no spotted stem weevil larvae in 50 stalks. Lodging in the taller hybrid was greater than 25%, while the shorter hybrid had less than 5% lodging. With only one year's observation, it is not known whether the shorter hybrid may have some stem weevil resistance, or if this was just a random occurrence.

Introduction
Interest in irrigated sunflowers is increasing in western Kansas as effects of decreasing irrigation well productivity, depletion of the Ogallala aquifer and rising fuel prices become more evident. Due to the relative newness of sunflowers as an irrigated crop, there is a scarcity of current research data on sunflower response to irrigation. There is even less information on the effectiveness of limited irrigation of sunflowers. Anecdotal reports from producers on sunflower response to irrigation range from "no better than dryland" to "fantastic". In an effort to better define sunflower response to irrigation and  (Table 6). All 2002 plots received a 1.5 in. irrigation on 18 June and 5 July to ensure adequate moisture for germination and establishment. Thereafter, control treatments were rain-fed dryland while the limited irrigation treatments were scheduled to maintain soil water content above 40 % using the KanSched irrigation scheduling software (Kansas State University) and data from the weather station on the Colby research station. Two identical irrigated treatments were maintained until 3 Sept. when the late irrigation treatment was given 1 in. more water (Table 8). Triumph 545A (standard height) was used both years, while Triumph 567DW (semi-dwarf) sunflowers were added to the 2002 trial, which was seeded on 18 June 2002 at a final population of 17,500 plants/a. This was less than desired (24,000plants/a) due to extreme drought and grasshopper pressure. Both years, plots were fertilized for a 3000 lb/a yield goal according to soil test results. Both years, stand counts were made in early July and 17.5 feet of two rows were hand harvested in each replicate in late Sept. and threshed in a stationary threshing unit approximately 2 weeks later.

2001
Sunflower populations were uniform across all irrigation treatments. Precipitation from May 1 through harvest was 10.85 in., which produced 1510 lb/a average dryland yield, while the average irrigated sunflower yield was 2780 lb/a with 8.35 in. of additional water (Table 7). The limited irrigation yielded 152 lb/a for each inch of irrigation. Irrigated replication 2 yielded only 390 lb/a less than the other irrigated replications due to non-uniform plant spacing (bunching and skips) even though the population was 21,000 plants/a. Gross returns, based on a $9.80/cwt cash price plus premium for oil content, were $162.02/a for dryland and $298.29/a for irrigation. The dryland yield in this plot was about 200 to 300 lb/a more than average in the area this year, which would indicate that the amount and timing of rainfall was quite beneficial to yield and oil content.

2002
Sunflower populations were uniform across all irrigation treatments, but had uneven spacing between plants characterized by four to five 2 ft skips per 100 ft of row. Precipitation, irrigation, grass-based evapo-transpiration (ET) and sunflower ET amounts are reported in Table 8. Yields and gross returns are reported in Table 9. The cumulative ET for this crop location was calculated by KanSched software (KSU) as 28.84 in., which is 8.6 to 9.7 in. more than the combined rainfall and irrigation amounts. The soil at planting time was too dry to allow penetration of a steel rod probe. The soil moisture content prior to irrigation is assumed to near permanent wilting point within the top 3 ft of soil. After 3 in. of irrigation just after planting, which all plots received, the steel rod probe penetrated to a depth of 42 to 46 in. It is estimated that the soil profile from 3 to 6 ft contained as much as 3 in. available water for crop growth. The 2002 growing season was about 5°F hotter than average and precipitation was 5 to 7 in. less than average.
The plots were not sprayed for insect control. While head moth damage was slight, stem weevil, Cylindrocopturus adspersus(LeConte), and stem borer, Dectes texanus (LeConte), pressure was heavy. Hybrid 545A had more than 25 % lodging and the majority of pith eaten away in the lower 2 ft of stem. Hybrid 567DW had less than 5 % lodging and relatively little of the lower stem pith eaten. Notably, examination of 50 stems of each hybrid revealed no spotted stem weevil larvae in 567DW compared to about 25 per stem in 545A (data not shown). Soybean stem borer larvae were found in both hybrids equally. Hybrid 545A matured about 10 days earlier than 567DW, which may have been a result of the differences in stem weevil pressure. Also, deer and bird predation of 25% in 545A and 10% in 567DW was recorded. Again, the difference in maturity date could account for the predation difference. The lodging difference could be partially due to maturity, partially due to less insect damage to the interior of the stalk and partially due to less mechanical wind force on the shorter hybrid. Also, the stalk diameter of 567DW was slightly larger than that of 545A. Yields were adjusted to account for lodging and predation to show the true irrigation effect (Table 9). Hybrid 545A's oil content was about 46.0 %, while hybrid 567DW's oil content was about 37 %. Hybrid 567DW has not been noted for above average oil content. Gross returns, based on a $12.75/cwt cash price (27 Nov. 2002) plus premium for oil content, or on $13.50/cwt for bird seed quoted the same day are reported in Table 9. These prices were higher than long-term averages; however, 2003 NuSun contracts are available locally for $11.50/cwt or more. Seed yield response to irrigation is reported in Figure 4 and ranged from 125 lb/a in. to 199 lb/a in., based on adjusted seed yield.
The adjusted dryland yield of 545A was similar to the average yield in the KSU dryland sunflower variety plots, located less than a half mile away, while 567DW yielded similar to the best yielding hybrid in the KSU variety plots. The differences in lodging and as-harvested versus adjusted seed yields underscore the importance of controlling stem pests. It is not known whether hybrid 567DW has a physiological or morphological resistance to stem weevil and the observations of one site-year are not sufficient to draw conclusions, but it is a possibility that needs further investigation. Recent research (Charlet, et al., 2001) shows 600 to 1100 lb/a seed yield increase for one insecticide application to control stem pests. Part of that increase is due to decreased lodging, but part is due premature death of plants caused by insect damage and associated diseases vectored by the insects. Thus, it is possible that the best adjusted yields reported in this study could have been 300 to 500 lb/a better with timely insect control. Seed yield was reduced by as much as 450 lb/a due to less than desired population and skips and doubles in row in 2001, and could have been reduced for the same reason in this plot, but there was no control to aid documentation. The adjusted seed yields could have possibly been 600 to 1000 lb/a higher and such yields have been seen in 2001 and 2002 in the NWREC irrigated NuSun sunflower performance trials and other trials in the area.   397.04B 1 Range in diameter in inches of 10 consecutive heads at a random location in plot. 2 Gross income based on cash price of $12.75/cwt (27 Nov., 2002) + oil premium of 2% price increase/each 1% oil above 40%, or bird seed price quote for the same time of $13.50/cwt denoted 'B', whichever produces the greatest gross income. 3 Yield adjusted to compensate for lodging and predation to better evaluate effect of irrigation. Lodging was 25%(545A) or 5%(567DW) and predation was 25%(545A) and 10%(567DW).

Irrigation treatment
Lbs./A inch 545A 567DW Figure 1. Seed yield response to irrigation of two sunflower hybrids. Yield response values are based on adjusted seed yield and assume no water available in the top three feet of soil and 3 in. water available in the three to six foot deep profile and 5.3 in. water use to develop plant prior to seed development. All treatments received 9.39 in. rain from 12 May '02 until 24 Sept. '02 and 3.0 in. irrigation for stand establishment. Treatment R-7 received an additional 6.6 in. irrigation. Treatment R-8 received an additional 7.7 in. irrigation.

Introduction and Procedures
An experiment was conducted near Manhattan, KS on a Reading silt loam soil with 2.5% organic matter and a pH of 5.7 to evaluate broadleaf weed control in winter wheat. Hybrid '2137' hard red winter wheat was seeded at 70 lb per acre on October 8, 2001. Precipitation of 0.9 inch was received within 1 week after planting, resulting in uniform germination and emergence of the crop and weeds. Fall postemergence (FP) treatments were applied to 3-to 4-leaf and 2-to 5-tiller wheat, and 1-to 4inch bushy wallflower and field pennycress rosettes on November 15 with 68 F, 68% relative humidity, and clear skies. Dormant (DOR) treatments were applied to tillering wheat, and 1to 3-inch rosettes of bushy wallflower and field pennycress on February 20 with 45 F, 41% relative humidity, and partly cloudy skies. Spring postemergence (SP) treatments were applied to fully tillered wheat, 3-to 4-inch tall bushy wallflower and field pennycress, and cotyledon to 1-leaf wild buckwheat on April 9 with 66 F, 43% relative humidity, and mostly clear skies. Treatments were applied with a CO 2 backpack sprayer delivering 20 gpa at 25 psi through XR8002 flat fan spray tips to the center 6.3 ft of 10-by 20-ft plots. The experiment was a randomized complete block design with three replications. Wheat injury was evaluated December 6 and April 16. Weed control was visually estimated on May 13. Wheat was harvested on June 27.

Results
Several fall postemergence treatments caused stunting that was apparent through early spring, but disappeared over the remainder of the season. Field pennycress infestations were light, and control was excellent with all treatments. Most treatments provided good control of bushy wallflower. Spring postemergence treatments that included Finesse, Amber, or Rave tended to give the highest wild buckwheat control. Wild buckwheat control with Rave and Finesse was lower with fall postemergence than dormant or spring postemergence applications, probably because of dry conditions in the fall. Wheat yields were erratic and not related to weed control. Although there were no visible injury symptoms, wheat yields with Starane plus Finesse treatments were less than the untreated check.

Introduction and Procedures
An experiment was conducted near Manhattan, KS on a Wymore silty clay loam soil with a cation exchange capacity of 18.4, 2.8% organic matter, and a pH of 5.8 to compare glyphosate products and additives for efficacy. Two rows each of velvetleaf, common sunflower, sorghum, and corn were planted as assay strips across each replication into conventionally tilled seedbed on June 8, 2002. Postemergence treatments were applied to 4 to 6 leaf (4-6 inch) velvetleaf, 8 leaf (6-8 inch) sunflower, V5 (8-10 inch) sorghum, and V5 (14 inch) corn on June 24 with 81 F, 50% relative humidity and clear skies. Treatments were applied with a compressed air, tractor mounted sprayer delivering 15 gpa at 18 psi through TT11003 flat fan spray tips to the center 10 ft of the plots, and perpendicular to the direction of the assay strips. The experiment had a randomized complete block design with three replications and 15-by 25-ft plots. Plant response was visually evaluated on July 23.

Results
Weed escapes were most common and occurred primarily in the tractor wheel tracks. Weed control was similar among all glyphosate formulations applied at equal acid equivalent rates and with a source of ammonium sulfate. Weed control with glyphosate was less if no ammonium sulfate source was included in the treatment. Class Act NG is an adjuvant from Agriliance that includes nonionic surfactant, fructose, and ammonium sulfate. Array is a guar based adjuvant from Rosens that reduces drift potential and provides a source of ammonium sulfate.

Introduction and Procedures
An experiment was conducted near Manhattan, KS on a Reading silt loam soil with a cation exchange capacity of 10.6, 3.2% organic matter, and a pH of 5.8 to compare glyphosate weed control programs and application timing with conventional weed control programs. 'Asgrow 3302' Roundup Ready soybeans were seeded 1.5 inches deep at 150,000 seeds per acre into conventionally tilled seedbed with adequate soil moisture on May 30, 2002. Preemergence treatments were applied to the soil surface following planting. Postemergence treatments at 3 weeks after planting (3 WAR) were applied to 2-trifoliate soybeans, 1 to 12 inch Palmer amaranth, 1 to 6 inch velvetleaf, 1 to 6 inch sunflower, and 4 to 8 inch ivyleaf morningglory on June 20 with 87 F, 42% relative humidity and mostly clear skies. Postemergence treatments at 4 weeks after planting (4 WAR) were applied to 3-trifoliate (8 inch) soybeans, 2 to 20 inch Palmer amaranth, 4 to 12 inch velvetleaf, 12 to 16 inch sunflower, and 4 to 12 inch ivyleaf morningglory on June 26 with 83 F, 65% relative humidity and mostly clear skies. Postemergence treatments at 5 weeks after planting (5 WAR) were applied to 4-trifoliate (12 inch) soybeans, 6 to 32 inch Palmer amaranth, 12 to 18 inch velvetleaf, 24 to 28 inch sunflower, and 6 to 18 inch ivyleaf morningglory on July 3 with 75 F, 89% relative humidity and cloudy skies. Treatments were applied with a compressed air, tractor mounted sprayer delivering 15 gpa at 20 psi through TT11003 flat fan spray tips to the center two rows of the four 30-inch row plots. The experiment had a randomized complete block design with three replications and 10-by 25-ft plots. Palmer amaranth, velvetleaf, and common sunflower were evaluated on August 20. Ivyleaf morningglory was evaluated July 23. Soybeans were harvested on October 21.

Results
None of the herbicides caused important injury to soybeans. Adequate moisture was present at planting to stimulate an early flush of weeds.
However, minimal early season precipitation resulted in poor activation and weed control from preemergence treatments. Early weed emergence combined with warm weather stimulated rapid early season weed growth. By 4 weeks after planting, weeds were already up to 20 inches tall. Consequently, Flexstar plus Fusion treatments at 4 WAR were not very effective. Postemergence treatments, especially Flexstar plus Fusion realistically would have been applied earlier than 4 WAR due to the large weed size. Even though preemergence treatments were not very effective for early season Palmer amaranth control, sequential programs with Touchdown gave better control than Touchdown alone. Velvetleaf control with glyhosate was good, but declined as application date was delayed. Touchdown and Roundup treatments gave complete control of common sunflower (cultivate) at all application times. Sequential Touchdown or Roundup applications gave the best ivyleaf morningglory control. Soybean plots that were deemed too weedy to harvest were assigned a zero yield. Soybean yields were low and variable due to the dry conditions during the first 2 months of the growing season.
Highest soybean yields occurred with sequential treatments of Touchdown or Roundup at 3 and 6 WAR, and sequential treatments of a preemergence herbicide followed by Touchdown at 4 WAR. Soybean yields with a single Touchdown treatment at 4 WAR were lower than sequential Touchdown or Roundup, or PRE fb Touchdown at 4 WAR treatments. Soybean yields tended to decrease as Touchdown applications were delayed from 4 WAR to 6 WAR with or without a Boundary PRE foundation treatment. However, sequential treatments with Boundary fb Touchdown always tended to be better than comparable Touchdown alone treatments. Boundary and/or Flexstar plus Fusion treatments had poor soybean yields due to the poor weed control.   No Treatment 0 LSD (5%) 11 9 6 14 7 a / = sequential application; COC = Crop Oil Plus petroleum oil with 17% emulsifier from Farmland Industries applied at 1% v/v; 28%N = 28% UAN liquid nitrogen fertilizer applied at 2.5% v/v; AMSU = ammonium sulfate applied at 2% w/w or 17 lb/100 gal spray. b PRE = preemergence; WAR = weeks after planting. c Paam = Palmer amaranth, Vele = velvetleaf; Cosf = common sunflower; Ilmg = ivyleaf morningglory.

Introduction and Procedures
An experiment was conducted near Assaria, KS on a Crete silt loam soil with 2.4% organic matter and a pH of 5.4 to evaluate several herbicide treatments in different spray carrier solutions for Japanese brome control in 'Jagger' hard red winter wheat seeded October 1, 2001. Fall postemergence (FP) treatments were applied to 3-to 4-leaf and 3-tiller wheat, and 1-to 3-leaf Japanese brome on November 2 with 63 F, 38% relative humidity, and clear skies. Spring postemergence (SP) treatments were applied to multiple tillered wheat and Japanese brome on March 30 with 50 F, 37% relative humidity, and mostly clear skies. Treatments were applied with a CO 2 backpack sprayer delivering 20 gpa at 25 psi through XR8002 flat fan spray tips to the center 6.3 ft of 10-by 30-ft plots. The experiment was a randomized complete block design with three replications. Wheat injury was evaluated November 14, April 12, and May 8. Japanese brome control was evaluated on May 8 and May 23.

Results
Application of Maverick, Olympus, or Everest with liquid nitrogen fertilizer as carrier resulted in wheat foliar burn, which was greater with fall than spring treatments, and increased with fertilizer carrier concentration. However, crop response was temporary and new growth was unaffected. All fall treatments provided excellent Japanese brome control, which generally was better than comparable spring treatments. Olympus and Everest gave better Japanese brome control than Maverick with spring applications. Japanese brome control with spring applications of Maverick was higher when applied with liquid nitrogen carrier than water only carrier. Scattered downy brome in the plot area generally was not controlled as well as Japanese brome, especially with Olympus treatments.

Introduction and Procedures
An experiment was conducted near Manhattan, KS on a Reading silt loam soil with 2.5% organic matter and a pH of 5.7 to evaluate winter annual grass control and imidazolinone resistant wheat tolerance to Beyond and competitive treatments. Cereal rye, downy brome, and cheat seed were broadcast in strips across each replication and incorporated prior to establishing the experiment. An experimental Clearfield-resistant hard red winter wheat variety from ApriPro was seeded at 70 lb per acre on October 8, 2001. Precipitation of 0.9 inch was received within 1 week after planting, resulting in uniform germination and emergence of the crop and weeds. Fall postemergence (FP) treatments were applied to 3-to 4-leaf and 2-to 5-tiller wheat, 2-to 4-leaf and 1-to 3-tiller cheat and downy brome, and 3-to 5-leaf and 2to 5-tiller rye on November 15 with 66 F, 70% relative humidity, and clear skies. Spring postemergence (SP) treatments were applied to multi-tillered wheat, cheat, downy brome, and rye on March 28 with 68 F, 35% relative humidity, and clear skies. Treatments were applied with a CO 2 backpack sprayer delivering 20 gpa at 25 psi through XR8002 flat fan spray tips to the center 6.3 ft of 10-by 20-ft plots. The experiment was a randomized complete block design with three replications.
Wheat injury was evaluated March 3 and May 15. Winter annual grass control was visually estimated on June 7. Wheat was harvested on June 26.

Results
Fall and spring applied Beyond caused general stunting to Clearfield wheat. Wheat injury was much higher with Beyond plus Finesse than with Beyond alone. Maverick, Olympus, and Everest also caused minor injury symptoms on wheat. Fall applied Beyond provide excellent control of downy brome, cheat, and rye. The addition of Clarity to Beyond tended to reduce downy brome and rye control compared to Beyond alone. Weed control with Beyond was lower for spring than fall treatments, especially for rye and downy brome. Cheat control with Olympus and Everest was excellent with both fall and spring treatments. Fall applied Maverick also provided excellent cheat control, but control was slightly lower with spring treatments. Downy brome control with Maverick, Olympus, and Everest was less than cheat control. Downy brome control tended to be slightly higher with Maverick than Olympus. Downy brome control was poor with Everest. All treatments provided good control of bushy wallflower (data not presented). Wheat yields generally corresponded to weed control and crop tolerance.