The effect of climatic factors to vegetation and yield formation in soya varieties of the northern ecotype

To overcome the foodder protein deficite, grain legumes, and the soya particularly, should be used. The commonl soya varieties originate from South-East Asia, and for the northern regions the special varieties have been bred. Breeding technologies are usually based on the aboveground part traits which correlate with the productivity and other desired parameters. But in a model variety the physiological function of roots and also the donor/acceptor relations of leaves and roots should be considered. In our examintation, the development of roots and the aboveground parts in soybean was compared in the ultra early short-stem variety Mageva and the early varieties Svapa, Krasivaya Mecha, Lancetnaya, Belor, BMM 1/90 of the northern ecotype. The investigations were condudcted in Orlovskaya destrict in the years, contrasting on climatic conditions. The adaptation to water deficite was shown to occur as an increase of the root mass and absorbtion surface. A dry matter distribution between the organs of plants, its reutilization and nitrogen reutilization were estimated in the yaears with different moistening. In all varieties the growth of aboveground parts correlated with the seed yield.