Doses e épocas de aplicação de cloreto de mepiquat em algodão colorido brs topázio

Abstract

Colored cotton is a genetic material still little cultivated in Brazil, having advantages such as the color of the fiber, which remains until the final product, so it is not necessary to use chemicals to dye it and promoting textile production with less environmental impact. However, it is a material that, in general, has low fiber quality and low productivity. It is up to the research to work on the improvement of the characteristics of the referred genetic material and that consequently would stimulate the increase of its cultivation. The objective of this study was to evaluate the growth and development of BRS Topázio cotton as a function of the application of the mepiquat chloride growth regulator at different doses and times. The experiment was conducted in a greenhouse at the Federal Rural University of Pernambuco, Serra Talhada Academic Unit (UFRPE-UAST). A completely randomized design was used in a 5x2 factorial arrangement, with 3 replications, 5 doses of mepiquat chloride (0.0; 0.07; 0.14; 0.21; 0.28 L ha-1) were applied at two different times (30 and 60 days after the emergency). Plant height, internode length, stem diameter, leaf area, number of nodes, number of bolls, number of flowers, number of apples, insertion height of the first flower bud, insertion height of the first flower were studied. , cottonseed mass, fiber mass, stone mass, aerial fresh matter mass, aerial dry matter mass, root fresh mass, root dry matter mass, total fresh matter mass and total dry matter mass. For data analysis we used the statistical software Sisvar 5.6, in which the results were submitted to analysis of variance and regression analysis. The variables, plant height, leaf area, stem diameter, node number, internode length, number of flowers, apple number, number of bolls, shoot fresh matter, root fresh matter, total fresh matter, shoot dry matter, total dry matter, root dry matter, fiber production, stone production and stone cotton production, responded to the effects corresponding to different doses and application times. The variables insertion height of the first flower and the insertion height of the first flower bud were not significantly influenced by mepiquat chloride. BRS Topázio cotton presents higher sensitivity to mepiquat chloride when applied at 30 DAE;