Interrelations between traits productivity and adaptability of soybean cultivars at different weather types in conditions of Russia south

Using biometrical analysis of results obtained from 7-year ecological trial of soybean varieties (VNIIMK, Krasnodar) there is stated the following: • ·The achievement of leaf area index 4.2 m2 m-2 is a limit for seed yield increase when precipitation sum increases in a period before bean formation; the exceeding of this value leads to seed yield decrease in summer drought; • ·The reducing of leaf area of different soybean genotypes crops from 6.5 to 1 m2 m-2 is compensated by seed yield per 1 m2 of leaves increase to such degree that seed yield per hectare do not change at an average; therefore the breeding for transpiration reduction without productivity potential decline is possible; • Harvest index, leaf xeromorphy estimations and, in limited degree, early ripening also belong to criteria for soybean plant and family selection for summer drought resistance.