The study of early maturity of soybean collection material

The soybean early ripeness plays very important role in the crop production in the conditions of the short growing season of the Moscow Region. It depends on genetic factors, growing conditions, features of weather conditions during the growing season. The study of traits of early maturity (vegetative, generative periods, vegetation period, interphase development periods) was conducted on the soybean collection material, which are 190 varieties and lines of Russian and foreign breeding of various origins, very early and early ripening groups in the Moscow Region. Collection samples were tested in different climatic conditions of 2015-2016, which made it possible to carry out a study of the influence of weather conditions on the degree and rate of maturation of vegetative and generative plant organs. We described the variability and duration of the following periods of soybean development: "sprouting-flowering", "flowering-maturation", "sprouting-ripening". The duration of the vegetation period is given in the sums of active temperatures. We determined the variability of the interfacial periods of soybean development: from sowing to mass sprouting, from mass sprouting to the beginning of budding, from the beginning of budding to the beginning of flowering, from the beginning of flowering to the beginning of the formation of beans, from the beginning of the formation of beans to the beginning of technical ripeness, from the beginning of technical ripeness to mass biological ripeness. We indicated specific features, dependence on the weather conditions, the average indicators, compliance with the average annual climatic indicators. We found the most early-ripening soybean varieties and breeding lines (SAT=1520-1710°C) in conditions of 55° N. It was found that soybean collection samples are characterized by low variability of the vegetative, generative and vegetative periods. The interphase periods of development also tended to weak variability, excepting the periods "from the beginning of budding to the beginning of flowering" and "from the beginning of flowering to the beginning of the formation of beans", which should be considered in breeding practice.