Biometric indices of soybean varieties depending on the application of fertilizer, growth regulators and moisture-retaining agent

Abstract

Purpose. To reveal the peculiarities of growth and deve­lopment of soybean varieties depending on the application of organic fertilizers, plant growth regulators and moisture-retaining agent in the conditions of the Forest-Steppe of Ukraine and determine their biometric indices. Methods. Soybean varie­ties ‘Ustia’, ‘Kano’ and ‘Hieba’ were included in the study. A month before soybean sowing, moisture-retaining agent (hydrogel Aquasorb) was introduced in the zone of the future row as 10-cm strips at a dose of 300 kg/ha. Organic fertilizer Parostok (grade 20) was applied twice: at the 3–5 leaf stage and at the 9–11 leaf stage. Growth regulators Vermystym D and Agrostymulin were introduced at the budding stage. Results. The positive effect of the use of growth regulators on the overall increase in the height of soybean plants was revealed. In particular, when using Vermystym D in ‘Ustia’ variety, their height increased by 0.7–3.0 cm, Agrostymulin – by 0.2–3.7 cm. At the same time, the use of growth regulators contributed to some increase in the number of flowers per plant: the variety ‘Ustia’ – by 0.1–1.0 pcs.,‘Kano’ – by 0.0–1.0 pcs., ‘Hieba’ – 0.0–0.8 pcs. When using growth regulator Vermystym D, the number of beans on plants of ‘Ustia’ variety grew by 0.4–1.0 pcs., with the introduction of Agrostymulin – by 0.3–2.2 pcs., in ‘Kano’ – by 0,0–1.1 and 0.3–1.4 pcs., for the variety ‘Hieba’ – by 0.3–1.1 and 0.6–1.9 pcs. respectively. In combination with other factors, the use of growth regulators was effective. Conclusions. On average, over the years of research, the maximum number of grains in ‘Ustia’ variety was formed under the condition of plant nutrition with Parostok fertilizer and the use of growth regulators Vermystym D (36.2 pcs.) and Agrostymulin (35,5 pcs.). The application of Parostok fertilizer contributed to an increase in the height of attachment of the lower bean in ‘Ustia’ variety by 0.6–2.4 cm, in ‘Kano’ and ‘Hieba’ – by 1.0–2.4 and 0.4–1.7 cm respectively. In the case of growth regulators use, no significant changes in this indicator were recorded. The maximum mass parameters of 1000 seeds for the varieties ‘Ustia’ and ‘Kano’ were obtained in the combined use of hydrogel Aquasorb, organic fertilizer Parostok and Agrostymulin growth regulator – 160.3 and 166.8 g, respectively, for ‘Hieba’ variety with using the growth regulator Vermystym D – 193.7 g.