Effectiveness of predecessors at growing winter rye (Secale Cerealе L.) in the conditions of Northern Steppe of Ukraine

Topicality. Nowadays, the relevant issue is the influence of predecessors on the grain productivity for the modern varieties of winter rye depending on the sowing dates and mineral nutrition, the study of which allows to reveal the biological potential of plants to a fuller extent and to significantly increase the yield of this crop in the Northern Steppe zone of Ukraine. Purpose. To study features for formation of grain productivity of modern winter rye varieties depending on the predecessors against the background of different sowing dates and the level of mineral nutrition in the soil and climatic conditions of the Northern Steppe. Materials and Methods. In the 2018–2021, the studies were conducted on the basis of Experimental Farm “Dnipro” of State Enterprise Institute of Grain Crops NAAS in four-factor field trial. Winter rye of Pamiat Khudoierka and Stoir varieties were sown after spring barley and sunflower against the background of different levels of mineral nutrition of plants in three terms: early (September 5–10), optimal (September 20–25) and late (October 5–10). Results. According to the research results, a significant influence of predecessors on the winter rye yield was established. The highest level of yield was obtained for the Stoir variety, which was sown in the period from 20 to 25 September. At the same time, on average over the years of research, the highest yield was observed in variants with nitrogen feeding plants on freeze-thawed soil: after spring barley – 6.47 t/ha, after sunflower – 5.03 t/ha. The Pamiat Khudoierka variety also provided the highest yield in these variants of the experiment – 6.17 and 4.72 t/ha, respectively. However, the difference in yield between varieties, taking into account the maximum indicator, depending on the predecessors was respectively 0.30 and 0.31 t/ha. Conclusions. Conclusions. According to the results of the research, it was found that sowing of winter rye after spring barley and sunflower in the most optimal terms, namely September 20–25, and the applying 45 kg a.i./ha nitrogen in early spring, ensured the formation of the highest yield in the Stoir variety, which was 6.47 and 5.03 t/ha, respectively. Keywords: winter rye, predecessor, varieties, sowing dates, feeding crops, yield