Interaction of acetyl-CoA carboxylase enzyme inhibiting herbicides with auxin herbicides on ryegrass

Rubens Antonio Polito,Rafael Dysarz,Anderson Luis Nunes,Larissa Pasqualotto,Rafaela Cinelli,Tamara Heck

doi:10.1590/0103-8478cr20200462

Abstract

ABSTRACT: This study aimed to evaluate the antagonistic effect of the mixture ofacetyl coenzyme-A carboxylase (ACCase) enzyme inhibiting herbicides and auxin herbicides in Lolium multiflorum and to determine mechanisms to mitigate this possible effect. The first experiments were conducted by associating the herbicide clethodim (108 g a.i. ha−1), quizalofop-p-ethyl (54 g a.i. ha−1), and clethodim + quizalofop-p-ethyl (108+54 g a.i. ha−1) with 2,4-D (1005 g a.e. ha−1) or triclopyr (720 g a.e. ha−1), in addition to the sole application of the respective graminicides. Another experiment included clethodim (54; 81; 108; 162; 216 g a.i. ha−1), quizalofop-p-ethyl (27; 40.5; 54; 81; 108 g a.i. ha−1), and clethodim + quizalofop-p-ethyl (54+27; 81+40.5; 108+54; 162+81; 216+108 g a.i. ha−1) mixed with 2,4-D (1005 g a.e. ha−1), or triclopyr (720 g a.e. ha−1), in addition to the control treatments without herbicide application. In the second experiment, herbicides clethodim (108 g a.i. ha−1), quizalofop-p-ethyl (54 g a.i. ha−1), and clethodim + quizalofop-p-ethyl (108+54 g a.i. ha−1) in combination with the herbicides 2,4-D (1005 g a.e. ha−1) or triclopyr (720 g a.e. ha−1)had malathion (1000 g a.i. ha−1) or glyphosate (720 g a.e. ha−1) mixed, in addition to the sole applications of the graminicides. The herbicide clethodim + quizalofop-p-ethyl did not present an antagonistic interaction with the auxin herbicides, and obtained 85% weed control. To obtain control similar to the sole application of this graminicide, the dose of the herbicide clethodim needs to be increased by 20%. However, the mixture of the herbicide quizalofop-p-ethyl with 2,4-D and triclopyr affects the ryegrass control. The use of strategies that increase the absorption of ACCase herbicides or the inhibition of P450 enzymes are ways to mitigate the antagonistic effect caused by the association of the two auxin herbicides.

Highlights

Ryegrass (Lolium multiflorum) is an annual weed that has natural reseeding capacity, and it is present in wheat, maize, oats, and barley crops (KASPARY et al, 2014)
With respect to the formulated mixture of clethodim + quizalofop-p-ethyl, the auxin herbicides had a negative effect only at 21 and 28 days after application (DAA) (Figures 2A and 2B), with no differences between the auxins corresponding to the level of antagonism
The formulated mixture of clethodim + quizalofop-p-ethyl obtained better performance over ryegrass control when associated with auxin herbicidesthan other graminicides

Summary

Introduction

Ryegrass (Lolium multiflorum) is an annual weed that has natural reseeding capacity, and it is present in wheat, maize, oats, and barley crops (KASPARY et al, 2014). The control of this weed was mainly conducted with the use of glyphosate herbicide that inhibits the EPSPS enzyme. The use of herbicides inhibiting the enzyme acetyl coenzyme-A carboxylase (ACCase) has become the best option. The death of the plant occurs because these herbicides inhibit the action of the ACCase, which participates in the biosynthesis of fatty acids, blocking the production of phospholipids that act on plant growth constituting the formation of membranes (DE OLIVEIRA Jr., 2011)

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Conclusion