Responsiveness of alfalfa varieties to inoculation by nodule bacteria

Five new strains of alfalfa nodule bacteria and production strain 445a were evaluated. The high activity of a new strain III isolated from a suspension washed from alfalfa seeds of European origin was revealed. Pre-sowing inoculation with strain III increased the productivity of alfalfa plants of Pastbishchnaya 88 and Taisiya varieties by 23–44% and 18–61% in three out of six mowing. The positive effect of pre-sowing inoculation with new strains I, II, IV, V on the height (+4.7–9.5 cm) of Pastbishchnaya 88 plants in the third, fourth and fifth cycles, in the summer (June–August) was noted. The effect on height in plants of the Taisiya variety is not noted. The efficiency of symbiosis in the summer period during inoculation with strains I, II, IV, V was 105–127% in the Pastbishchnaya 88 variety and 101–150% in the Taisiya variety. A positive, high, linear correlation dependence of the productivity of alfalfa plants of Pastbishchnaya 88 and Taisiya varieties on their height was revealed.