Fiber Quality of Colored Cotton As a Function of Potassium Fertilization in the Semi-Arid Region

Naturally colored fiber cotton is an essential alternative green and organic for the textile industry, as it does not require chemical dyeing. However, the low availability of potassium during production can directly affect the quality of the fiber. Based on this, this study aimed to evaluate the fiber quality in naturally colored cotton cultivars submitted to potassium fertilization in a semi-arid region. The experimental design was in randomized blocks, with four replications, and the treatments were arranged in split plots. In the plot, the following were allocated: five K rates (0, 60, 120, 180, and 240 kg ha(-1) of K2O); and in the subplots, the four colored cotton cultivars (BRS Rubi, BRS Safira, BRS Topazio, and BRS Verde). The results showed that K is involved in the length, uniformity, short fiber index, micronaire index, and reliability index of naturally colored cotton fibers. A longer fiber length of 30.45 mm was obtained at a dose of 240 kg ha(-1) of K2O for the cultivar BRS Topazio. In addition, a higher uniformity (84.95%) was achieved with the dose of 240 kg ha(-1) of K2O for BRS Verde. The dose of 240 kg ha(-1) of K2O reduced (8.62% and 11.28%) the short fiber index in the cultivars BRS Rubi and BRS Safira, respectively.