The influence of irrigation and seeding rates on the yield of female components lines of corn in conditions of unstable moisture in Ukraine
¹Poltava State Agrarian University, Educational and Research Institute of Agrotechnology, Breeding and Ecology, Department of Breeding, Seed Science and Genetics, 1/3, Skovorody Str., UA36003 Poltava, Ukraine
²Poltava State Agrarian University, Educational and Research Institute of Agrotechnology, Breeding and Ecology, Department of Plant Science, 1/3, Skovorody Str., UA36003 Poltava, Ukraine
³LLC Poltava Sad, village of Rozsoshentsi, UA36000 Poltava, Ukraine
*Correspondence: shakaliysveta@gmail.com
Abstract:
In regions with insufficient rainfall or different climates, the use of irrigation systems is an important element of corn growing technology. The variation in corn yield on non-irrigated lands is 533% and 200% greater than on irrigated lands. Corn yield also depends heavily on sowing density. The optimal plant density is an unstable value. Field studies were conducted in conditions of unstable moisture in the central part of the Forest-Steppe of Ukraine, which according to agro-climatic zoning belongs to the zone of unstable moisture. The experimental design included: assessment of the characteristics of weather conditions during the years of research (2021–2023) and their impact on seed yield (factor A); determination of seed productivity of female components linesof hybrids of different maturity groups P4/440, P5/320, P6/240 (factor B); the impact of growing hybrids with and without irrigation (factor C); the effect of different seeding rates on seed yield (60, 70, 80, 90 thousand seeds per ha-1) (factor D). The test results show that during the change in corn productivity depending on genetic properties, seeding rate and irrigation, the late-ripening hybrid P4/440 was characterized by the highest grain yield when grown under irrigation, with a seeding rate of 90 thousand similar seeds per ha-1 a decrease in the seeding rate from 90 to 80, 70, 60 seeding rate thousand seeds ha-1 was accompanied by a decrease in the yield of seeds of female components lines: in the early-ripening hybrid P6/240 – by 0.31, 0.63 and 1.10 t ha-1 or 5.7, 11.5 and 20.1%, in the mid-ripening hybrid P5/320 – by 0.59, 1.08 and 1.42 t ha-1 or 9.8, 17.9 and 23.5%, in the late-ripening hybrid P4/440 – by 0.39, 0.74 and 1.28 t ha-1 or 6.0, 11.4, 19.8%. The greatest influence on the formation of yield is the irrigation factor – 53%. Genetic properties influenced 28%. gradual increase in the yield of seeds of female components lines of culture when increasing the seeding rate from 60 to 70 thousand seeds ha-1 (by 0.01 t ha-1) and reaching a maximum at a rate of 80 thousand seeds ha-1 (by 0.05 t ha-1). But with an increase in the seeding rate to 90 thousand ha-1, the seed yield sharply decreased by 0.13 t ha-1. The highest yield in variants without irrigation was observed when using the minimum seeding rate – 60 thousand seeds ha-1. A gradual increase in the seeding rate without irrigation
led to a negative result, in particular, a decrease in the average yield for corn hybrids by
0.07–0.31 t ha-1 or 1.8–7.9%. Hybrids reacted differently to the seeding rate and cultivation on rainfed and irrigated land. Early ripening hybrid P6/240, mid-ripening P5/320 and late-ripening P4/440 hybrids formed the highest seed yield when grown under irrigation with a seeding rate of 90 thousand seeds ha-1. When grown without irrigation, the best conditions for the formation of plant components and high yield were noted at the lowest seeding rate of 60 thousand seeds ha-1. The minimum seeding rate ensured the production of seeds with a high mass of 1,000 seeds.
Key words:
corn, female components lines, hybrid, irrigation, seeding rate