Evaluation of yield, fiber and seed quality of white and colored cotton (gossypium hirsutum L.) grown under different irrigation levels

This study was conducted in 2024 at the Experimental Field of Application Center of Çukurova University to evaluate the effects of different irrigation levels on yield, fiber quality, and crude seed protein and oil content in white- and colored-fiber cotton cultivars. The experiment was arranged in a split-plot design with three replications. Three cotton cultivars of Gossypium hirsutum L., including one white-fiber and two colored-fiber varieties, were used as plant material. Irrigation treatments were applied using a drip irrigation system at full irrigation (100%) and deficit irrigation (50%) levels. This study investigated the effects on various traits, including yield, ginning efficiency, fiber fineness, fiber length, fiber strength, fiber elongation, fiber uniformity, short fiber content, fiber maturity, yarn quality index, seed oil content, and seed protein content. Irrigation levels significantly affected only seed cotton yield and seed protein content, while no significant effects were observed on other traits. Cultivar effects were significant for seed cotton yield, ginning efficiency, fiber length, fiber strength, short fiber content, fiber uniformity, yarn quality index, and seed oil content. The interaction between irrigation level and cultivar was significant only for fiber fineness. Although the effects of irrigation levels were not statistically significant, deficit irrigation tended to increase some fiber traits while decreasing others compared to full irrigation. Under deficit irrigation, fiber length decreased by 0.37 mm, fiber fineness increased by 0.18 units (undesirable), fiber strength increased by 0.70 g/tex (favorable), fiber elongation increased by 0.1% (favorable), short fiber content increased by 0.27% (undesirable), fiber uniformity decreased by 0.4% (undesirable), and seed oil content decreased by 1.3%.