Peculiarities of pea yield formation under application of measures to increase tolerance to drought stress in the Right Bank Forest Steppe of Ukraine

Abstract

Purpose. To establish regularities in the formation of the yield and quality of pea seeds under the application of measures to increase the crop tolerance to drought stress in the zone of unstable soil moisture of the Right Bank Forest Steppe of Ukraine. Methods. Field research was carried out in the Uladivske-Liulyntsi Experimental Breeding Station of the Institute of Bioenergy Crops and Sugar Beet of the National Academy of Agrarian of Sciences (Vinnytsia Region, zone of unstable soil moisture of the Right Bank Forest Steppe of Ukraine) in 2015−2019. Pea of the ‘Yulii’ variety was grown according to the scheme of a four-factor field experiment with the use of Aquasorb (200 kg/ha), soil treatment with the mycorrhizal biopreparation Mycofriend (1 l/ha), seed treatment with plant growth regulator Kelpak SC (3 l/t) and foliar application of microfertilizers Biovit (7 l/ha, BBCH 14) and Freia-Aqua Bean (1.5 l/ha, BBCH 14). Aquasorb moisture retainer was applied under early spring cultivation with Amazone ZA-TS 3200 spreader. Results. On average, 6.4 beans were formed per plant; of them 5.3 with seeds. At the same time, the best option was with seed treatment with Kelpak SC growth regulator, introduction of moisture-retaining polymers Aquasorb and mycorrhizal biopreparation Mycofriend into the soil, followed by treatment of plants with microfertilizers Biovit or Freia-Aqua Bean, which contributed to the formation of 6.2–6.3 filled beans per plant. At the same time, in the case of using additional elements of agricultural technology, the percentage of filled beans increased to 85−86 (77.5% in the control). On average over the years of research, seed treatment with the growth regulator Kelpak SC, application of Aquasorb and the mycorrhizal biopreparation Mycofriend to the soil, followed by the treatment of plants with microfertilizers Biovit or Freia-Aqua Bean contributed to the formation of pea yield at the level of 5.55 and 5.57 t/ha with the yield of crude protein of 1.43 t/ha, fat 0.09 t/ha, and starch 2.28 and 2.65 t/ha, respectively. Conclusions. Among the factors influencing the formation of pea yield, the largest share has year (31%), especially in the treatments without the application of hydrogel. Application of hydrogel determined 29% yield increase, growth regulator 19%, mycorrhizal biopreparation 11%, and micro fertilizers 9%.