EFEITO DO CLORETO DE MEPIQUAT NO DESENVOLVIMENTO E RENDIMENTO DA CULTURA DO ALGODOEIRO EM HIDROLÂNDIA - GO

Abstract

Cotton exhibits an indeterminate growth habit, which can favor excessive vegetative development and compromise the balance between vegetative and reproductive structures. In this context, the use of plant growth regulators constitutes an important strategy for managing plant architecture. This study aimed to evaluate the effect of the commercial dose and reduced doses of mepiquat chloride on the vegetative development and yield of the cotton cultivar FM 911GLTP. The experiment was conducted in a greenhouse at the Instituto Federal Goiano – Campus Hidrolândia, GO, between March and September 2025, in a completely randomized design with four treatments and six replicates. The treatments corresponded to the absence of the regulator and the application of 100%, 50%, and 25% of the recommended dose of PIX HC. Five foliar applications were carried out, starting 30 days after emergence, at seven-day intervals. Vegetative and reproductive characteristics were evaluated, as well as lint and seed masses and yields. The data were subjected to analysis of variance, and the means were compared using the Scott-Knott test at a 5% probability level. Mepiquat chloride significantly reduced plant height and the number of nodes, and delayed the opening of the first boll. No significant differences were observed for stem diameter, number of vegetative and reproductive branches, number of open bolls, and lint and seed masses. The 25%, 50%, and 100% doses did not differ from each other regarding the control of plant height and number of nodes, demonstrating that, under the experimental conditions, the reduced doses showed similar efficiency to the commercial dose in controlling vegetative growth. Studies under field conditions are necessary to determine the most agronomically appropriate dose.