Acetolactate synthase and acetyl coenzyme A carboxylase inhibiting herbicides in Avena fatua

Abstract

Avena fatua is a very important weed in wheat worldwide. This also occurs in the Mexicali Valley, BC., where acetolactate synthase- and acetyl coenzyme A carboxylase-inhibiting herbicides are used to control this grass. In the search for the best alternative for the producer, this research aimed to estimate the efficiency of these two groups of herbicides to control Avena fatua. The trials were carried out during the 2021-2022 autumn-winter cycle in three ejidos in said Valley (República Mexicana, Nayarit, and Sombrerete). The experiments included herbicides representative of each group. Acetolactate synthase was composed of iodosulfuron, flucarbazone, and pyroxsulam and acetyl coenzyme A carboxylase was integrated by fenoxaprop and pinoxaden. The experiments were arranged in randomized complete blocks with four replications. An analysis of variance was carried out for weed control and density and crop yield; the effectiveness of herbicides was measured using a non-linear regression model. Weed control efficiency and weed index were estimated. The results indicate that the best group of herbicides was acetyl coenzyme A carboxylase. For example, in the projection of the level of damage, in the República Mexicana experiment, we have fenoxaprop= 77.16+0.78*DAA-0.009*DAA^2, that is, the damage to the weed increases slightly over time, at least until the 56 DAA. On the contrary, mesosulfuron loses efficiency of 6.41% daily in the second stage of the evaluated period: 138.20-6.41*DAA+0.07*DAA^2. In efficiency at the same site, fenoxaprop has 83.15% and Iodosulfuron only 37.5%.