Influence of inoculant seed treatment and foliar fertilization on the duration of vegetation and interphase periods of soybean cultivars

Abstract

Offering new soybean varieties to agricultural producers necessitates research on their adaptation to certain soil and climatic conditions of cultivation. Therefore, the sign of the length of the vegetation period is crucial for growing soybeans in specifc soil and climatic conditions. The studies carried out in 2019–2021 have shown a signifcant dependence of the length of the vegetation period on weather conditions. Thus, the weather conditions in 2021 caused the longest vegetation period for soybean varieties, and the weather conditions in 2020 determined the shortest vegetation period for this legume. It was found that with the introduction of N 30P60K60 the shortest vegetation period was in the precocious variety of soybean Samorodok and it lasted 101 days. The longer vegetation period was in the precocious soybean cultivar Rogiznyanka and lasted with an average of 113 days. Early maturing soybean cultivars Orpheus and Triada had an average vegetation period of 112 and 122 days. For the middle early maturing varieties of Eurydice and Arrata the vegetation period lasted 113 and 127 days, respectively. In medium-ripe varieties Azimuth and Aurora the vegetation period lasted 118 and 121 days, respectively. Pre-sowing seed treatment with Rhizoactive extended the vegetation period of the Samorodok soybean cultivar by one day, and the Rogiznyanka, Triada, Orpheus, Arrata, Eurydice, Azimuth and Aurora soybean varieties by two days. On average, over the three years of research, it was found that in the Western Forest-Steppe conditions against the background of N30P60K60 application, seed treatment with Rhizoactive and Fulvohumin foliar fertilization, the Arrata soybean cultivar had the longest vegetation period with the duration of 130 days. Thus, varietal characteristics made the most significant factor influencing the duration of soybean vegetation in the research. At the same time, inoculation of seeds with Rhizoactive and foliar fertilization of crops with Fulvohumin changed the duration of the vegetation period of the studied soybean varieties by only 1–3 days. The studied varieties differed signifcantly in the initiation and rate of growth and development phases of soybean plants. Since the degree of compliance of growth and development factors with the optimal value varies signifcantly depending on the phenological phase, it is advisable to grow several varieties of different maturity groups in order to achieve stable soybean production. Key words: soybean, cultivar, vegetation period, fertilizers, Rhizoactive, Fulvohumin.