Sowing terms as a way to increase yield of soybean varieties with different vegetation period
Purpose. To study of the influence of sowing terms on plant growth and development, formation of indicators of individual productivity and seed yield by soybean varieties with different vegetation period in conditions of the western Forest-Steppe of Ukraine. Methods. Field experiment, calculation and weight, mathematical statistics. Results. Weather conditions in the years of the research were characterized by high average daily temperatures against the background of uneven distribution of precipitation by phases of soybean development, which together with the studied factor had a significant impact on the growth and development of soybean plants and seed yield formation. It was found that the studied soybean varieties with different growing seasons react differently to growing conditions. The timing of sowing significantly affects the height of attachment of the lower bean, the number of beans per plant and seeds in the bean, the weight of 1000 seeds and the weight of seeds per 1 plant. However, they have almost no effect on the number of seeds in the bean. It was investigated that the soybean variety Diadema Podillya forms the highest yields at the optimal and late sowing dates, while the soybean of the KiVin, Knyazhna, Khutoryanochka and Triada varieties – at the late sowing period (second decade of May). The increase in seed yield compared to sowing in the optimal time (first decade of May) was 6.6%, 3.1%, 13.8% and 9.6%, respectively. Conclusions. Sowing terms in interaction with the weather conditions of the growing season, have a significant impact on the formation of indicators of individual productivity and seed yield of soybean varieties with different growing seasons. That is why in the conditions of climate change, uneven moisture supply during the growing season and the emergence of new varieties it is advisable to continue research to study the impact of sowing dates, in interaction with other factors, on the formation of individual productivity and yield of soybean seeds.