The assessment of a complex treatment of soybean seeds with fungicides and inoculator

The Russian and foreign scientists have already proved an important role of the symbiosis of rhizobia and soybean through which plants obtain the necessary nitrogen amount from the air for effective growth and protein synthesis. At the same time, they stated the seed treatment with some fungicides suppress the rhizobia growth and lowered the formation of nitrogen-fixing nodules in fields. Now, the search of fungicides effective against pathogens but not suppressing rhizobia at joint application is actual in an agrotechnological system. In 2020-2021, we treated soybean seeds with an inoculant Hycout super soya based on a bacterium Bradyrhizobium japonicum. It did not reduce soybean plants infestation with diseases but caused additional seed yield 0.37 (2020) and 0.27 t/ha (2021) through the symbiotic activity. The combined application of fungicides and an inoculant showed their effectiveness against fusarium wilt. The soybean seed treatment with Maxim, CS, Delit Pro, CS, and Tebu 60, OE combined with the inoculant did not suppress the formation of nitrogen-fixing nodules on soybean plant roots and did not reduce their air-dry weight. The highest amount (33 and 83 pcs./plant) and weight (0.09 and 0.32 g/plant) of nodules are noted on plant roots in a variant when treated the seeds with a mix Maxim, CS + inoculant, L.