Effectiveness and selectivity of herbicides applied under preemergence conditions in weed management for coffee crops

Abstract

The coffee plant is sensitive to weed competition, which negatively affects its growth and development. Thus, the proper and safe use of herbicides is extremely important for weed management to allow the crop to develop its maximum productive potential. The objective of this study was to evaluate the control efficacy of different herbicides under pre-emergence conditions and assess their selectivity for coffee crops. Two experiments were carried out in the field, in randomized block designs, with four replicates and eight treatments, totaling 32 experimental plots. The treatments were: unweeded control; weeded control; sulfentrazone + diuron 1.4 L ha -1 ; sulfentrazone + diuron 1.7 L ha -1 ; sulfentrazone + diuron 2.0 L ha -1 ; sulfentrazone + diuron with indaziflam 1.4 + 0.15 L ha -1 ; respectively, indaziflam 0.15 L ha -1 ; and oxyfluorfen + chlorimuron 3.0 L ha -1 + 0.08 kg ha -1 , respectively. The treatments were applied prior to the emergence of weeds in a directed spray between the crop rows. Evaluations of weed control in the area, phytotoxicity to the crop, branch length, and internode distance of coffee were conducted at 30, 60, 90, and 120 days after treatment application (DAA). In general, all treatments guaranteed greater than 80% efficacy up to 60 DAA. After this, some treatments suffered reductions in efficacy, and did not guarantee satisfactory control up to 120 DAA. For Digitaria nuda, the most effective treatments were those that contained indaziflam alone or in combination with sulfentrazone + diuron, and oxyfluorfen + chlorimuron for 60 DAA. In both experiments and the two species analyzed, the indaziflam treatments guaranteed efficacy percentages above 80%, even at 120 DAA. All treatments were equally selective for the coffee plants under the conditions evaluated.

Herbicide mixtures for post-emergence control of horseweed in coffee interrow

“…Contudo, maior lucratividade pode ser alcançada com aumento da produtividade ou redução nos custos de produção, ou mesmo pela otimização das atividades da cadeia produtiva, por exemplo, o adequado manejo das plantas daninhas (RONCHI et al, 2005) Nas últimas décadas, o controle das plantas daninhas tem sido frequentemente realizado por meio da aplicação de herbicidas, como medida eficiente e econômica para diminuir sua incidência e proliferação (FIALHO et al, 2012). Contudo, um dos maiores desafios no manejo de plantas daninhas é evitar a seleção de biótipos resistentes aos herbicidas, sendo necessário alterar constantemente as práticas utilizadas no controle de plantas daninhas, visando evitar ou retardar o aparecimento de plantas daninhas resistentes (CHRISTOFFOLETI, LÓPEZ-OVEJERO, 2003;GONÇALVES NETTO et al, 2021).…”