Evaluation of pre-plant herbicides for maize (Zea mays L.) cultivation

Abstract

Objective: To evaluate the efficacy of different herbicides for weed control, prior to the establishment of maize crops (Zea mays L.).

Design/methodology/approach: An experiment was established during the SS/2022 and FW/2023 cultivation cycles. The design was completely random blocks and four repetitions with the following treatments: control, glyphosate 726 g ha^-1; paraquat 400 g ha^-1; glufosinate-ammonium 300 g ha^-1; saflufenacil 42 g ha^-1; 2,4-D amine 718.5 g ha^-1; dicamba + 2,4-D 120 + 240 g ha^-1; picloram + 2,4-D 64 + 240 g ha^-1; glufosinate-ammonium + 2,4-D 300 + 479 g ha^-1; glyphosate + 2,4-D 726 + 479 g ha^-1 and BH 03 (bioherbicide) concentration at 1%. The damage to weeds was evaluated 7, 14 and 21 days after application (DAA).

Results: The most efficient control of polote (S. eurylepis) was with glyphosate, paraquat, glufosinate-ammonium, saflufenacil, dicamba + 2,4-D, glufosinate-ammonium + 2,4-D, and glyphosate + 2,4-D, all of them with control levels equal or higher than 90%. In zacate panizo (U. reptans), the most efficient were glyphosate and paraquat, with values higher than 97%.

Limitations on study/implications: The results correspond to S. eurylepis and U. reptans as most frequent weeds. Conditions of excessive rain or wind delay the optimal application time. After sowing, early weeds can escape control.

Findings/conclusions: Glyphosate and paraquat were the most efficient herbicides during the evaluation in both agricultural cycles.