Efficiency of pre-sowing treatment of soybean seeds with bioinoculants at different treatment terms

Purpose. To study the influence of the timing of pre-sowing seed treatment with bioinoculants on soybean productivity. Methods. Field, quantitative, monolith method, mathematical and statistical one. Results. The influence of the timing of seed treatment with microbial preparations Rizoline, Anderiz, Histik, Rizoaktiv on the symbiotic apparatus formation, individual and seed productivity of soybeans was analyzed. The highest efficiency of bioinoculants was observed when treating seeds on the day of sowing. The number of nodule bacteria increased from the use of Rizoline by 106%, of Anderiz – by 108%, of Histik – by 64%, of Rizoaktiv – by 87%; the mass – by 32, 22, 17 and 18%, respectively. Extending the period before sowing weakened the positive effect of bioinoculants on the formation of the symbiotic apparatus. The largest number of nodule bacteria was recorded when using Anderiz, the largest mass – when using Rizoline. The highest individual plant productivity was formed when seeds were treated on the day of sowing, while its decrease was noted with an increase in the interval. Seed inoculation with biological preparations increased the yield: 40-45 days before sowing – by 7-10%, o19-21 days – by 10-16%, on the day of sowing – by 13-19%. The best yield increase (+0.23, +0.36, +0.43 t/ha) was provided by Anderiz at all treatment terms. Conclusions. It was established that seed treatment with bioinoculants at different times contributed to the optimization of symbiotic, individual and seed productivity of soybeans. The highest seed productivity was formed when seeds were treated on the day of sowing. The most effective was pre-sowing seed treatment with the bioinoculant Anderiz with the bioprotector Rhizosave. The increase in seed yield was 0.43 t/ha (20%) when treated on the day of sowing, 0.36 (16%) after 19-21 days, and 0.23 t/ha (10%) after 40-45 days.