THE EFFECT OF THE COMBINED USE OF BIOAGENTS AND PLANT ADAPTOGEN ON THE PRODUCTIVITY AND OIL CONTENT OF SPRING RAPESEED ON LEACHED CHERNOZEM AND GRAY FOREST SOIL

The article presents the results of field experiments conducted in 2017-2019 on two types of soils in the Republic of Tatarstan (leached chernozem and gray forest soil) to assess the effects of combined use of bioagents based on Bacillus spp. bacteria (RECB-95 B and RECB-50 B) and plant adaptogen (extract from millet seedlings) on the productivity of spring rapeseed of the Gedemin variety. The study included pre-sowing seed treatment and foliar top dressing of vegetating plants in the phase of 3-4 pairs of leaves. It was found that the complex use of drugs significantly improved the structural elements of the crop: the number of productive pods increased to 40 pcs./ plant on chernozem and 37 pcs./ plant on gray forest soil, the number of seeds in the pod increased to 27 and 23, respectively, and the number of unproductive pods decreased to 2 pcs./ plant. The maximum yield increase was achieved in the RECB-50 B variant with adaptogen: 1.05 t/ha (54.9%) on chernozem and 0.70 t/ha (53.8%) on gray forest soil. The gross oil harvest increased to 1,246.1 kg/ha (+57.2%) and 894.0 kg/ha (+47.5%), respectively. A synergistic effect was revealed between the complex of Bacillus strains and biologically active substances of the adaptogen, which was especially pronounced on less fertile gray forest soil. The relative yield increases on both types of soils turned out to be comparable, which indicates the high efficiency of biological products under stressful conditions. The main mechanism of action of the studied techniques is the stimulation of growth processes and the formation of seed yield without a cardinal change in their biochemical composition. The results demonstrate the prospects of the combined use of bioagents and adaptogens in spring rape cultivation technologies.