The influence of irrigation, row space, and plant density on the yield of cotton Gossypium hirsutum (L.) in the conditions of the Southern Steppe of Ukraine

Abstract

Goal. To determine the effectiveness of irrigation of early ripening medium-fiber cotton of Pidozerskyi 4 variety in the conditions of the Southern Steppe of Ukraine. Methods. Field, laboratory, statistical. Results. On cotton crops grown in non-irrigated conditions, the total water consumption from the 0–100 cm soil layer was 2210–2587 m3/ha. This indicator increased with a decrease in the width of rows and sowing rates and significantly depended on precipitation during the growing season and soil moisture reserves. As for irrigated areas, the total water consumption here was higher by 585–752 m3/ha (2962–3172 m3/ha). The highest coefficient of water consumption was for irrigation — 1164.3 m3/t, for growing cotton with a row spacing of 60 cm and a seed sowing rate of 250,000 seeds/ha, and the minimum — 898.4 m3/t in non-irrigated conditions with a row spacing of 90 cm and sowing rate of 350,000 pieces/ha. When growing cotton with different widths between rows and the rate of seed sowing, an increase in the yield of raw cotton from the use of irrigation was observed. Conclusions. Vegetation irrigation compensates for the insufficient amount of moisture in dry years for the formation of a higher yield of raw cotton. Irrigation conditions with a row spacing of 60 cm and a seed sowing rate of 300,000 seeds/ha enable plants to fully realize their genetic potential and produce the maximum yield of raw cotton — 3.07 t/ha. On average, the factor under the influence of agrotechnical cultivation measures, the yield of cotton under irrigation increased by 20.1% compared to options without irrigation. 1250 m3/ha for 70% NV should be considered as the optimal irrigation rate for early maturing medium-fiber cotton of the Pidozerskyi 4 variety in the Southern Steppe of Ukraine.