CONTROLE QUÍMICO DE Spermacoce verticillata EM PRÉ-SEMEADURA DE SOJA

Abstract

In Brazil, Spermacoce verticillata is a growing problem in soybean crops, as it is a weed that is difficult to control and tolerant to glyphosate. The objective of this work was to evaluate the best alternative for chemical control of shrubby false buttonweed at different stages of development. The experiment was carried out in a greenhouse, at the research station of the Gapes group in Rio Verde, Goiás, with a completely randomized block design in a 12x3 factorial scheme (12 treatments and 3 weed stages) with four repetitions. Visual control assessments were performed according to the visual scale of plant injury at 7, 14, 21, 28 and 35 days after application (DAA), and on that last date, the dry mass of the aerial part and the height of treated plants were also measured. The objective was to evaluate 6 formulated herbicides, isolated and in association with glufosinate-ammonia salt and 1 control, totalizing 12 treatments. It is concluded that the shrubby false buttonweed is a weed that is difficult to control, especially in more advanced stages of development. Pre-sowing soybean management is extremely important. It is also essential for management in the early development stages, with Protox-inhibiting herbicides being responsible for presenting better performance in all evaluated stages.