Seleção de linhagens de algodoeiro em condições de sequeiro no agreste paraibano

Abstract

Cotton is a crop of great importance for semi-arid regions, as it has a certain tolerance to drought. Rainfed cotton farming becomes a significant strategy used by producers in the region to generate employment and income. That said, the objective of the present work was to select cotton genotypes tolerant to water stress in the Agreste of Paraiba. 20 cotton lineages were evaluated in trials conducted at the Empaer Experimental Station, in the city of Alagoinha-PB, in 2021 and 2022. The variables evaluated were: seed cotton yield, fiber yield, fiber percentage, length, uniformity, short fiber index, resistance, elongation, micronaire index and reliability index. Individual and joint analyzes of variance, Scott-Knott mean grouping test and the selection index proposed by Mulamba and Mock were performed. The evaluated materials present a high coefficient of genotypic determination for all analyzed traits, demonstrating the presence of variability, with the possibility of desirable genetic gains. The variables length, uniformity, short fiber content, strength and reliability index show averages within the standard required by the textile industry for all strains. The traits with the most expressive selection gains are fiber yield (8.62%) and seed cotton yield (6.83%). The lines selected as the most promising are: BRS 286(T), CNPA SA 2019 – 204, CNPA SA 2019 – 115, CNPA SA 2019 – 185, CNPA SA 2019 – 206, as they present better performance for most yield traits and fiber quality, being indicated to form new populations in the cotton improvement program. Among the selected materials, the first three lineages stood out in the year 2021, which presented very low water availability. In view of this, they may present even more promising results for the semi-arid region, requiring further studies.