Controle de buva (Conyza spp.) e leiteiro (Euphorbia heterophylla) com herbicidas pré-emergentes na cultura da soja

Abstract

Soybean is the most widely grown crop in Brazil, and its production has been consistently increasing over the years. The success of soybean cultivation depends on various factors, one of which is effective weed control to prevent competition for nutrients, water, and minerals. Proper crop management, with a focus on controlling weed invasions, ensures successful farming and prevents potential losses. The objective of this study is to evaluate the efficacy of pre-emergent herbicides with different modes of action in controlling weeds in soybean cultivation. The research was conducted on a private farm, with sowing taking place in November 2022 and harvesting in March 2023. The experiment employed five herbicides in a mixture, following a randomized complete block design with four replications. The herbicide applications were carried out using a backpack sprayer with CO2. The treatments used were: Metribuzin; Ammonium Salt of Glufosinate + S-Metolachlor; Flumioxazin + S-Metolachlor; (Imazethapyr + Sulfentrazone) + Trifluralin + Saflufenacil, and control. The data were analyzed using the non-parametric Kruskal-Wallis test, followed by analysis of variance with Tukey's test at a 5% significance level. The results showed that the treatments Metribuzin + Trifluralin + Saflufenacil, (Flumioxazin + S-Metolachlor) + Trifluralin + Saflufenacil, and (Imazethapyr + Sulfentrazone) + Trifluralin + Saflufenacil provided the best weed control after 70 days of evaluation for horseweed (Conyza spp.). For wild poinsettia (Euphorbia heterophylla), the treatment (Imazethapyr + Sulfentrazone) + Trifluralin + Saflufenacil exhibited higher efficacy. There were no significant differences observed among the treatments in terms of yield components.