Componentes morfoagronômicos de algodão colorido sob diferentes doses de adubação mineral

Abstract

Cotton is a fiber of great global importance, essential for the textile industry. In Brazil, colored cotton production, especially in the Northeast region, is emerging as a sustainable alternative to dyeing white fiber, a practice that can generate environmental impacts and health risks. Therefore, adequate nutritional management is essential to ensure fiber productivity and quality while minimizing soil damage. This study aimed to evaluate the effect of different mineral fertilizer doses on the morphoagronomic characteristics of two colored cotton cultivars in the Brejo region of Paraíba. The experiment was conducted in a dryland system in the experimental area of the Federal University of Paraíba (UFPB), Campus II, in the city of Areia, Paraíba state. A randomized block experimental design in a 2 x 4 factorial scheme was used, with two colored cotton cultivars (BRS Jade and BRS Rubi) and four fertilizer doses (0%, 50%, 100% and 150% of the recommendation), with three replicates. Plant height, height of insertion of the first fruiting branch, stem diameter, number of fruiting branches per plant, number of bolls per plant and productivity were evaluated. Analysis of variance revealed that, among the cultivars, there were significant differences (p < 0.05) for the height of insertion of the first fruiting branch and number of fruiting branches per plant, in addition to a significant difference (p < 0.01) for productivity. Regarding fertilization, significance (p < 0.05) was observed for the number of fruiting branches per plant and productivity, as well as significance (p < 0.01) for plant height and fruiting branch insertion height. The dose corresponding to 100% of the nutritional recommendation was as effective as the 150% dose, which did not result in significant gains in colored cotton production in the semiarid region of Paraíba. The cultivar BRS Jade showed greater vegetative vigor and productivity than BRS Rubi.