The Turkestan region is a cotton-growing zone in South Kazakhstan, but also the northernmost cotton-growing area in the world. Annually, medium-staple cotton (Gossypium hirsutum L.) cultivation occurs on 115,000–125,000 ha, with 80,000–85,000 ha grown in the Districts of Maktaaral and Zhetysay, Kazakhstan. This region is highly susceptible to salinity, drought, invasion of dangerous pests (cotton budworm, beet borer, spider mites, and aphids), and diseases (fusarium blight [wilt] and gummosis). An extremely high salt content and aridity in the arable soil are the main limiting factors of that region, hence, genotype selection through genetic principles is the most effective and economical way to reduce their negative impacts on vegetation. Therefore, the research on developing resistant cotton cultivars suitable for such soil and climatic conditions is most relevant. Considering the above situation, assessment of newly developed high-yielding cotton cultivars with fiber quality of types III–IV for tolerance to heat and drought, salinization, and pests and diseases ensued during 2019, 2020, and 2021 at the Agricultural Experimental Station of Cotton and Melon Growing, Atakent, Kazakhstan. Their promising cotton genotypes resulted from strains developed through intraspecific and interspecific diallel hybridization. The newly developed eight cotton cultivars, grown on more than 92% of the hectarage in the Southern region of Kazakhstan, are PA-3031, PA-3044, M-4005, M-4007, M-4011, Bereke-07, Myrzashol-80, and M-4017.
Medium-staple cotton (Gossypium hirsutum L.), salinity, drought, insect pests and diseases, seed cotton yield, fiber quality traits
Long-time and extensive breeding work developed highly productive cotton cultivars of medium-staple size, grown only for 118–122 days, with a high rate of boll retention and opening, fiber yield (38.0%–39.4%), and fiber quality of type IV-IV that meets the requirements of the textile industry. In the cultivars’ testing program, promising cotton cultivars, i.e., Maktaaral-4003, Maktaaral- 4006, Maktaaral-4015, and Maktaaral-4017, excelled the standard cultivar in almost all the parameters. These cotton genotypes are sources of economically valuable traits widely used in longterm hybridization programs.