Impact of Different Levels of Drought Stress on Yield and Yield Components in Some Cotton (Gossypium hirsutum L.) Cultivars

This study aimed to assess the yield and yield components of various cotton cultivars under different levels of drought stress. In the experiment, three irrigation treatments (I-100, I-75, and I-50) and three cotton cultivars were included. Analysis of the two-year data showed that water treatments significantly affected all traits except the number of seeds per boll. Full irrigation treatment (I-100) had higher values for seed cotton yield, plant height, number of monopodial and sympodial branches, number of nodes of first fruiting branches, number of nodes, HNR, number of bolls, boll weight, seed cotton weight per boll, and 100-seed weight than those of other water stress applications. Depending on the water stress applied, yield losses of 25.60% in I-75 and 54% in I-50 were observed compared to full irrigation. As a result of the application of water stress (I-75 and I-50), plant height, the numbers of monopodial branches, sympodial branches, first fruiting branches, nodes, and bolls were reduced, and boll weight (g), seed cotton weight per boll (g), and 100-seed weight decreased, while ginning percentage was increased; number of seeds per boll was not affected. These results also revealed that there were significant differences among cultivars (Kartanesi, Stoneville 468 and FiberMax 832) in terms of many investigated traits. The Stoneville 468 and Kartanesi cultivars were found to have superior values for yield and ginning percentage. According to the results of a two-year study, water stress negatively affected cotton yield and yield components. By demonstrating how specific cotton cultivars uniquely respond to deficit irrigation, this study offers novel baseline data and practical cultivar recommendations to mitigate agricultural productivity losses under climate change. Based on the results of the study, it was concluded that drought stress is a limiting factor for successful cotton production.