EFFICACY OF PREPARATION RISOTORPHINE APPLICATION IN GRASS PEAVINE CULTIVATION TECHNOLOGY
To improve mineral nutrition, yield capacity and quality of legumes while preserving soil fertility, it is necessary to use inoculants. Field experiments were conducted in 2015-2017 on the basis of North-Caucasus research institute of mountain and foothill agriculture of Vladikavkaz scientific center. Experiments were laid in 4-fold replication. The plot area was 17 m<sup>2</sup>. The plots location is randomized. Method of sowing is wide-row (row spacing is 45 cm), seeding rate - 0,8 million viable seeds/ha. The risotorphine inoculation of grass peavine seeds significantly stimulated the development of symbiotic apparatus. The number of nodules per plant in the flowering phase after inoculation increased 2,1-2,4 times. The most effective was application of phosphate-potassium fertilizers in the rate P<sub>45</sub>K<sub>45</sub> together with the risotorphine treatment. The dynamics of the nodules weight per plant had a similar trend. The area of leafy grass peavine reached its maximum values in the flowering phase - 19,6-30,4 thousand m<sup>2</sup>/ha depending on the variety and variant. Most leafy plants had variants with the joint application of bacterial preparation P<sub>45</sub>K<sub>45</sub>. The risotorphine application was effective for all variants. The preparation effect was more while its joint application with phosphate-potassium fertilizers. Plants of these variants formed the largest number of both beans and seeds on grass peavine plants - 11,6-12,9 and 30,6-32,8 pcs./plant, respectively. The largest seeds were formed by variety Racheyka - weight of 1000 grains within 196,7-240,5 g. The risotorphine application both on the natural fertility background and with different doses of phosphate-potassium fertilizers contributed to the highest yield increase in both tested varieties - 0,67 t/ha.