Yield and Quality of Naturally Colored Cotton Fiber Fertilized with Phosphorus Rates in the Brazilian Semiarid

Cultivating naturally colored fiber cotton has excellent potential for the Northeast of Brazil. However, its cultivation in the semiarid occurs with low use of technology and inputs in soils with the low phosphorus content. This work evaluated the productivity and fiber quality of naturally colored cotton cultivars under phosphorus fertilization in the Brazilian semiarid region. The experimental design was randomized blocks, with treatments arranged in split plots and four replications. The five P doses were allocated in the main plot, and four cotton cultivars were in the subplots. Variance analyses were performed for the characteristics evaluated in each agricultural harvest. Tukey test was used to compare the averages for cultivars and agricultural harvests. Increased P availability increased productivity and fiber quality of naturally colored cotton cultivars. Maximum fiber yield was obtained at 240; 240; 199.11, and 60 kg ha(-1) in the first crop, respectively. The maximum fiber length was reached at 80.86 kg ha(-1) in the BRS Verde cultivar. The maximum uniformity was obtained with the 138.49 kg ha(-1), and the cultivar BRS Topazio obtained greater uniformity. Fiber strength increased with the application of P2O5.