Dependence of the yield of soybean varieties and the elements that make it up on the weather conditions of the Amur region

The article presents the results of assessing the dependence of the onset and duration of the growth and development phases of soybean varieties, yield and the main elements that make it up on air temperature and precipitation in years with different meteorological conditions. The purpose of the research is to establish the influence of the hydrothermal regime on the onset of phenological phases and the duration of interphase periods, the formation of yield and elements that determine the productivity of soybean varieties in years with different meteorological conditions. The research was conducted at the Far Eastern State Agrarian University in the southern agricultural zone of the Amur Region under humid conditions in 2017 and 2019 and in excessively humid 2018. The objects of the research are soybean varieties included in the State Register of Breeding Achievements of the Russian Federation for the Far Eastern (12) Region: early-ripening Lidiya and mid-season varieties Umka and Persona. It was revealed in an excessively humid year: the interphase period of seedlings-third trifoliate leaf in soybean varieties is 3-4 days longer than in a wet year. The period of the third trifoliate leaf-flowering is 4-5 days longer in an excessively humid year. Under conditions of strong humidification, the flowering-bean formation period increases. The phase of bean formation-seed filling is reduced in dry conditions, and increased in humid ones. The studied varieties provide the highest yield - 1.96 t/ha in humid years, while under excessively humid conditions it is 0.69 t/ha less. At HTC = 2.25, soybeans have the lowest seed yield - 1.28 t/ha, with its decrease by 0.3, it increased by 51.5%, and with a decrease of 0.42, it increased by 53.9%. On average, the Umka variety yielded a high productivity of 1.93 t/ha, which was 0.26 t/ha higher than the Lydia variety and 0.34 t/ha higher than the Persona variety. The range of its variation was 0.54 t/ha for the Umka variety, 0.58 for Persona, and 1.18 t/ha for Lydia. There was a significant variation in the main productivity elements between the varieties (20.5-23.3%). The relationship between the productivity, its elements, and the HTC for the Lydia variety was a strong negative relationship during the germination-flowering period (r = - 0.89 - - 0.95), and an average negative relationship during the flowering-bean formation period (r = - 0.63 - - 0.69). A similar dependence is found for the Persona variety, first (r = - 0.70 - - 0.80), then an average negative (r = - 0.59 - - 0.67). For the Umka variety, as for Persona, a negative strong (r = - 0.77 - - 0.89) and average (r = - 0.67) relationship with the hydrothermal coefficient at the beginning of plant growth and development was established.