СИМБІОТИЧНА ПРОДУКТИВНІСТЬ ГОРОХУ ПОСІВНОГО ЗАЛЕЖНО ВІД ВПЛИВУ МІНЕРАЛЬНИХ ДОБРИВ ТА РЕГУЛЯТОРІВ РОСТУ В УМОВАХ ЛІСОСТЕПУ ЗАХІДНОГО

The article presents the results reached in our study of the influence of mineral fertilizers and growth regulators on symbiotic capacity of field pea in the conditions of Western Forest-Steppe. Experimental part was carried out during 2016-2018 on the field of the TPC Podilya at the SAEUP, the typical black soil, characterized as deep, low-humus, and heavy gravel on forest-like loams. The results indicate that the productivity of field pea largely depended on the effective interaction of the host plant and nodule bacteria. Application of phosphorus-potassium fertilizers and small doses of nitrogen fertilizers improved the biological fixation of nitrogen. Spray application of growth regulators at the budding-flowering phase continued the functioning of the red pigment of synthesized leghemoglobin in the nodules. The positive effect of mineral fertilizers and growth regulators on the symbiotic potentials of field pea plants was confirmed. The total symbiotic potential characterizes the state of legume-rhizobium symbiosis. The duration of active functioning of nodules on pea roots and their ability to fix biological nitrogen during the growing season define the magnitude of the active symbiotic potential. During the growing season, the total symbiotic potential indicators were the highest for the Chekbek variety and amounted to 13.1 thousand kg*days/ha (after application of N30P30K45 with the Vympel growth regulator). After application of the same combination of mineral fertilizer and growth regulator, the Gotovsky variety demonstrated - 10.6 thousand kg*days/ha, the Fargus variety – 10.0 thousand kg*days/ha.