Realization of the biological potential of the yield of conditioned seeds of white annual sweet clover under different methods of soil cultivation and the action of biological preparations

Abstract

Goal. To determine effective agrotechnical and biological factors for the realization of the biological potential of the yield of conditioned seeds of white annual sweet clover in the conditions of the Southern Steppe of Ukraine. Methods. The following methods were used in the research: field (to establish the patterns of growth and development of plants in natural conditions); visual-phenological (to fix the dates of onset and duration of interphase periods); measuring weight (for morphophysiological analysis and determination of biometric indicators and seed productivity); mathematical-statistical (to verify the obtained data using analysis of variance and evaluate the reliability of the results). Results. The study was conducted in 2023–2025 on the experimental field of the Institute of Climate Smart Agriculture of the NAAS, which was located within the land use of the Odesa State Agricultural Experimental Station of ICSA NAAS (Odesa oblast) on the southern heavy-clay chornozems. It was found that all the factors in the experiment influenced the yield of conditioned seeds of white annual sweet clover, among them the most (80.59%) — factor A (method of basic tillage). Against the background of various methods of basic tillage, from 0.546 t/ha (disking to a depth of 12–14 cm) to 0.689 t/ha (plowing to a depth of 27–30 cm) of conditioned seeds were obtained. Factor B influence (biologic treatment) was 15.79%. Depending on the selected biological product, an average of 0.584–0.655 t/ha of conditioned seeds was obtained. The effect of factor C (phase of plant development) in the experiment was the smallest (2.10%), which on average contributed to the production of 0.615–0.633 t/ha of conditioned seeds. Conclusions. Optimization of agrotechnical measures (the method of basic tillage, foliar feeding of plants with biological preparations in different phases of development) for growing white annual sweet clover made it possible to increase the yield of conditioned seeds of the culture in the conditions of the Southern Steppe of Ukraine. The maximum values of the yield of conditioned seeds (0.734 t/ha), the yield of conditioned seeds (89.48%), and the reproduction rate (73.39%) were obtained with 2-time treatment of annual white clover plants in the phases of the beginning of branching and budding with the preparation PMK-U «Universalnyi» against the background of plowing to a depth of 27–30 cm.