ADAPTIVITY OF SOYBEAN PLANTS TO EXTREME STESS FACTORS
The assessment of the compensatory ability of soybean plants to neutralize the negative consequences of hail was carried out in 2020 in the breeding field of the Armavir experimental station - the branch of the Federal Research Center VNIIMK. The purpose of the research was to estimate the value of soybean crop losses caused by massive damage to plants by hail and the prevailing unfavorable weather conditions during the rest of the growing season. The result revealed that the loss of most of the leaf apparatus (70-80%), fractures and injuries of the stems, lower plant density contributed to a significant reduction in the level of productivity of agrocenosis. The yield shortfall in the nurseries of preliminary and competitive variety testing averaged 27.6%, in the nursery of the initial material - 26.5%, in seed-growing and production areas - 25.0%. Despite external damage, the phytosanitary condition of the crops was satisfactory. Bacterial and viral infections were not observed, and fungal infections were observed in extremely limited areas. It was facilitated by arid and windy weather conditions during the growing season remaining after the hail storm. The studies have shown that the closer to the end of the growing season the soybean stalk is damaged by hail, the more negative its consequences will be. Thus, in the nursery of the initial material, the decrease in the yield of varieties of the early group of ripeness by 1.7 times exceeded the corresponding decrease in the yield of mid-season samples. Therefore, in areas of high hail hazard, farmers are recommended to sow soybean varieties of different ripeness groups for safety reasons, in order to reduce the amount of possible damage caused by hail.