Performance of Soybean Cultivars Depends on Sowing Time and Growth Regulators

Abstract

The effects of sowing time and pre-sowing seed treatment on the individual performance of soybean (Glycine hispida) plants and the yield of morphologically different cultivars are covered. The study had a split plot design in four replications in accordance with conventional methods. The first order plots were soybean cultivars: ‘Annushka’, ‘Kobza’ and ‘Malvina’; the second order plots were sown within various timeframes (early (6–8°C), medium (10–12°C), or late (14–16°C)); the third order plots were pre-sowing treatments of soybean seeds with Humisol, Adaptophyte, Rost-concentrate, and Fundazol. In all study years, the best individual performance of soybean plants was shown by cv. ‘Malvina’ treated with Adaptophyt before sowing and sown within the medium timeframe. The greatest mean yield of soybean seeds from cv. ‘Malvina’ (the mean yield across the study years was 2.34 t/ha) was harvested when the cultivar’s seeds were treated with Adaptophyt and planted within the medium timeframe. Soybean cv. ‘Annushka’ was significantly inferior to cvs. ‘Kobza’ and ‘Malvina’ in terms of performance: the difference was 0.31 and 0.43 t/ha, respectively. The seed yield increased to a large extent, when seeds were treated with the tested agents before sowing (the gain ranged from 0.10 to 0.38 t/ha). The effect of sowing time on the performance was the smallest. Thus, it was demonstrated that it was possible to achieve stable soybean yields in the Eastern Forest-Steppe of Ukraine due to adequate selection of cultivars, adherence to optimal sowing timeframes and application of growth regulators..