Vida Alone and in Tank Mixtures for Spring Kochia Control in Fallow

No herbicide treatment provided more than 50% kochia control at Garden City, KS, or 80% kochia control at Hays after the first week of application. At Garden City, KS, treatments of Vida (pyraflufen) plus glyphosate and 2,4-D or dicamba, glyphosate alone, or glyphosate plus 2,4-D or dicamba provided greater than 89% kochia control. At Hays, glyphosate alone or with 2,4-D, and Vida plus dicamba alone or with glyphosate had greater than 85% control of kochia.


Introduction
Vida is a protoporphyrinogen oxidase (PPO) inhibitor (Group 14) herbicide that includes compounds such as Cobra (lactofen), Flexstar (fomesafen), and Ultra Blazer (acifluorfin).This class of herbicides causes cell membranes to burst leading to rapid tissue death.Cell rupture happens so quickly that very little translocation to root or meristematic tissues occur.This can dramatically reduce the ability of this class of herbicides to kill weeds.Therefore, it was the objective of this study to tank mix Vida with herbicides that translocate better such as glyphosate, 2,4-D, and dicamba.

Experimental Procedures
Two experiments were conducted in western Kansas to evaluate Vida alone and in tank mixtures for early spring kochia control in fallow.Locations included the Kansas State University Agricultural Research Center near Hays, KS, and the Southwest Research-Extension Center near Garden City, KS.Application, environmental, and weed information are given in Table 1.Herbicides were applied using a tractor-mounted sprayer delivering 20 GPA at 30 psi at Garden City or a backpack sprayer at Hays delivering 15 GPA at 32 psi.Soil at Hays was a Roxbury silt loam with 2.7% organic matter and pH 7.9.Garden City soil was a Ulysses silt loam with 3.4% organic matter and pH 7.9.Plots were 10 × 32 feet (Hays) or 10 × 35 feet (Garden City) and arranged in randomized complete blocks with four replications.Visual kochia control was determined on May 17, June 2, and June 16, 2017, at Garden City; dates were 5, 21, and 35 days after treatment (DAT), respectively.At Hays, visual kochia control was determined on June 9, June 23, and July 7, 2017; dates were 7, 21, and 35 DAT, respectively.

Results and Discussion
By 7 DAT, no herbicide treatment provided more than 50% kochia control at Garden City or 80% kochia control at Hays (

Figure 3 .
Figure 3. Vida 2.0 oz/a plus glyphosate 22 oz/a and ammonium sulfate 2%, 34 days after treatment at Garden City, KS.

Table 2 )
. At Garden City, treatments of Vida plus glyphosate and 2,4-D or dicamba, glyphosate alone, or glyphosate plus 2,4-D or dicamba provided the best kochia control at 21 and 35 DAT (89 to 97%).Glyphosate alone or with 2,4-D, and Vida plus dicamba alone or with glyphosate controlled kochia 85 to 91% at Hays by 21 DAT, and only Vida plus dicamba with or without glyphosate controlled kochia more than 80% by 35 DAT.

Table 2 .
Vida alone and in tank mixtures for spring kochia control in fallow at two