Optimization of winter wheat sowing dates to climate change in the steppe zone of Ukraine

Abstract

In the dry steppe zone of Ukraine, the adaptation of winter wheat cultivation technology to climate change is an urgent issue. In particular, cultivars and sowing time are among the cheapest and most effective technology elements aimed at increasing the resistance of winter wheat plants to abiotic and biotic stresses. Therefore, the purpose of the study is to determine the effect of sowing time of different cultivars on the formation of winter wheat plant productivity. Based on the data of weather conditions in the pre-sowing, sowing and winter periods of the crop, a comparative analysis of temperature for 2013-2018 and 2019-2023 was carried out. Based on the results of field studies, the optimal sowing dates of modern winter wheat cultivars were determined, which resulted in higher yields. The research was conducted in the natural and climatic conditions of the Southern Steppe of Ukraine in the Mykolaiv Raion of Mykolaiv Oblast during the growing seasons 2018/2019 - 2022/2023. It was determined that plants had a longer duration of autumn vegetation (79-44 days) in 2021, while the shortest (44-10 days) - in 2022. It was determined that the shift of sowing dates of the studied cultivars by every 10 days (from September 20 to October 20), plant height decreased by 3.1-10.9% depending on the cultivar. On average, in 2019-2023, the highest yield of winter wheat grain was formed by the Duma Odeska cultivar (6.88 t/ha) when sown on October 10, and the lowest yield was formed by the Ozerna cultivar (5.56 t/ha) when sown on September 20. Thus, the best conditions for the formation of winter wheat grain yields were formed when sowing on October 10 (5.00-7.85 t/ha), and the worst - on September 20 (4.50-6.28 t/ha), depending on the variety and year of research. On average, by sowing date, the highest grain yields were formed by Duma Odeska in 2019 (7.22 t/ha), 2022 (6.12 t/ha) and 2023 (7.96 t/ha), and Ozerna in 2020 (5.20 t/ha) and 2021 (6.21 t/ha).