A dual tank precision sprayer to evaluate the interaction of 2,4-D choline and quizalofop-p-ethyl for control of volunteer corn in corn

Abstract

Quizalofop-p-ethyl (QPE) can control glufosinate/glyphosate-resistant corn (Zea mays L.) volunteers in corn resistant to aryloxyphenoxypropionates (Enlist corn). Mixing QPE with broadleaf herbicides such as 2,4-D choline can be antagonistic. A new precision sprayer with a dual tank/boom system can apply two herbicides simultaneously through separate nozzles, potentially reducing chemical antagonism. The objective of this study was to evaluate the interaction of QPE + 2,4-D choline applied via single tank or dual tank/boom system for controlling glufosinate/glyphosate-resistant corn volunteers in Enlist corn. Bin-run glufosinate/glyphosate-resistant corn was planted at 54,000 seeds ha⁻¹ to mimic corn volunteers. At 14 days after application (DAA), the dual tank/boom application of QPE (39 g a.i. ha⁻¹) and 2,4-D choline (1064 g a.e. ha⁻¹) achieved 85% volunteer corn control, compared to 70% control with single tank mix. The single tank application of QPE + 2,4-D choline was 7%–26% antagonistic until 28 DAA. Conversely, dual tank application of QPE and 2,4-D choline was additive. Although dual tank application of QPE and 2,4-D choline did not have transient antagonism (14 DAA), it was otherwise eliminated by 28 DAA using the higher rate of QPE (77 g a.i. ha⁻¹) in the tank mix. By 28 DAA, volunteer corn control was ≥92% across all treatments, with similar corn yield and no crop injury. The results suggest that a dual tank/boom system provided better volunteer corn control at 14 DAA; however, control was similar when using a higher rate of QPE (77 g a.i. ha⁻¹) with 2,4-D choline in tank mix at 28 DAA.