Estresse salino em genótipos de algodoeiro colorido no ciclo de produção após poda.

Abstract

He cultivation of colored cotton in the arid and semi-arid regions of the Brazilian Northeast has been affected by the scarcity of good quality water, being available water with high salt content, which limits the growth and production of the crops. In this sense, the objective was to evaluate the growth and the production of two genotypes of colored cotton, during different stages of development of the plant after pruning, in conditions of low and high salinity. The experiment was conducted in a protected environment (greenhouse) of the Center for Technology and Natural Resources of the Federal University of Campina Grande, Campina Grande - PB. The treatments consisted of two cotton genotypes ('BRS Rubi' and 'BRS Safira') submitted to ten salinity management strategies, varying the water quality applied in different phases of the plant cycle, using high salinity water (9 DS m-1), alternating with water of low salt concentration (0.8 dS m 1). The experimental design was in randomized blocks, resulting in 20 treatments (2 x 10) with three replications and three plants per plot. Variables of growth and cotton production were evaluated. The data were submitted to the Fischer test, comparing the means by Scott-Knott (p <0.05) for the irrigation management strategies and Tukey's test, (p <0.05) for the cotton genotypes. Among the genotypes 'BRS Sapphire' was the most tolerant to salinity, with higher growth and yield of cotton in feather. Saline water is harmful in the vegetative and flowering stages of plants and there is no recovery even after the stress suspension, the production of the cotton plume is more affected by the salinity when applied in the vegetative phase.