Yield plasticity of sunflower hybrids in the conditions of the Left-Bank Forest-Steppe of Ukraine

Purpose. To determine the level of productivity of sunflower hybrids, their stability and plasticity for cultivation in the Left Bank Forest-Steppe of Ukraine. Methods. The field experiment was performed in the conditions of the Left-Bank Forest-Steppe of Ukraine in 2016–2018. The peculiarities of plant growth and development, formation of yield of hybrids ‘Ukrainskyi F1’ (k), ‘P64LL125’, ‘P63LE10’, ‘P64F50’, ‘P64F66’, ‘P63LL06’, ‘NK Konti’ (k), ‘NK Brio’, ‘P64LE99’, ‘Laskala’, ‘Kupava’. Yield plasticity was calculated and analyzed by the Ebergard – Russell method. Results. Over the years of research, the average yield of sunflower hybrids in the Left-Bank Forest-Steppe of Ukraine varied from 2.71 to 4.04 t/ha. The lowest yield was shown by the ‘Ukrainskyi F1’ hybrid – 2.42–3.05 t/ha, the highest ‘Laskala’ – 3.79–4.26 t/ha. It was determined that in the conditions of the Left-Bank Forest-Steppe, there is no absolute predominance of medium-ripe hybrids in terms of yield. Conclusions. According to the results of the analysis of yield plasticity of sunflower hybrids, it was determined that the group of samples with high yield plasticity includes ‘Ukrainskyi F1’, ‘P64F50’, ‘P64F66’, ‘NK Konti’, ‘NK Brio’, ‘P64LE99’, ‘Lascala’ and ‘Kupava’. They respond to the improvement of the level of agricultural technology and provide the maximum yield only under the conditions of optimal factors. Hybrids ‘P64LL125’, ‘P63LE10’ and ‘P63LL06’ are more stable in response to changes in growing conditions without reductions in yield. As for the shares of the influence of the studied factors, the yield of the hybrid ‘Ukrainskyi F1’ was most influenced by the conditions of the year, ‘NK Brio’ – the sowing rate. For the ‘NK Ferti’ hybrid, the conditions of the year and the sowing rate are equally important.