Adaptation of cotton varieties to irrigated and rainfed lands in the south of Russia

Purpose: adaptation of early-ripening cotton varieties to irrigated and rainfed lands in the south of Russia. Materials and methods. The studies were conducted in 2022–2023. The objects of the studies were the medium-fiber cotton varieties Phoenix and Favorit. Biometric and phenological observations and yield records were carried out. Statistical processing of the obtained data was carried out according to the methodology of B. A. Dospekhov. Results. When cultivating cotton under irrigated conditions, the best biometric and economically valuable indicators were obtained in a medium-dry year in the Phoenix variety during the ripening phase: plant height – 105.4 cm, dry biomass – 7.38 t/ha, raw cotton weight of one boll – 5.45 g, fiber yield – 38.9 %. Research on the cultivation of cotton under rainfed conditions in the Stavropol Territory has shown that the highest height (61 cm) and the number of bolls (7.4 pcs.) were obtained in 2022 in the Phoenix variety. The Favorit variety should be singled out for its economically valuable traits. Conclusions. In Rostov region, when cultivating the Phoenix and Favorit cotton varieties under irrigation, the highest raw cotton yields were obtained in the moderately dry year of 2023 – 16.70 and 13.35 q/ha, respectively, against 8.20 and 4.70 q/ha in the very dry year of 2022. Research in the Stavropol Territory without irrigation showed that the maximum yield was obtained in 2023 when cultivating the Favorit variety – 19.5 q/ha. The Phoenix variety showed the yield lower by 2.2 q/ha in 2022 and in 2023 lower by 1.9 q/ha than the Favorit variety