Avaliação da eficácia de herbicidas pré e pós-emergente no controlo de infestantes na cultura de Cevada (Hordeum vulgare L.)

Abstract

Barley is a crop of great importance to the economy and contributes to food security, both for its use in human food and for its role in the animal food chain and industry. However, the occurrence of weeds represents one of the main limiting factors in its production and productivity. Due to the high destructive potential of weeds, several alternatives for their control have been used, with chemical control being particularly noteworthy. In this context, the present study was conducted at the Faculty of Agronomy and Forestry Engineering (FAFE/UEM) between June and October 2023, with the objective of evaluating the effectiveness of different herbicides in controlling weeds in barley cultivation. The experimental design used was a Randomized Complete Block Design (RCBD), with 6 treatments (control, weeding, basagran, MCPA, propanil, and pyrazolsulfuron-ethyl) and 4 replications. The variables analyzed included frequency, abundance, coverage, height, and biomass of weeds, as well as the yield of barley and its components. The data were subjected to statistical analysis using ANOVA, employing Fisher's exact test, followed by Tukey's mean comparison test, both with a significance level of 5%. The results showed that, in most of the parameters evaluated, there were no significant differences (P > 0.05), with the exception of barley height, yield, and weed biomass. In total, 13 weed species belonging to different families and genera were identified. The most prominent were: Commelina benghalensis, Cyperus rotundus, Tribulus terrestris, Gomphrena celosioides, and Portulaca oleracea. In terms of barley yield, it was observed that the treatment with propanil tended to reach a yield of 3 tons/ha. In weed control, the herbicides pyrazolsulfuron-ethyl and propanil proved effective, although the first herbicide caused a phytotoxic effect on barley in the early stages of development up to 30 days after application (DAA)(TRADUÇAO NOSSA)