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Purpose.To reveal the adaptive potential of stem lettuce varieties (Lactuca sativaL. var.angustanaIrish) according to the parameters of yield, ecological plasticity, stability and adaptability in the conditions of the Western Forest-Steppe of Ukraine. Methods.The stability and plasticity of stem lettuce yield was evaluated according to S. A. Eberhart and W. A. Rassel method. Soil and climatic conditions of the research area were generally favorable for lettuce growth and development. Research methods: field, laboratory and statistical. Results.Stem lettuce varieties showed different duration of the interfacial period of germination – technical ripeness: for ‘Pogonych’ variety it was 35 days, which made it possible to collect marketable products 6 days earlier than in the control. ‘Cobra’ variety showed the largest leaf area (13 109.12 m2). The value of the yield index of the rosette of leaves and stems over the years of research was in the range of 53.2–57.0 t/ha. Variety ‘Pogonych’ showed the highest rates of Yp.p. and Yd. – 74.0 and 7.8 t/ha, respectively. The stem lettuce varieties had a high coefficient of agronomic stability > 70%. ‘Tseltus’ variety showed the highest value of the index of environmental conditions (bi= 1.07), which indicates its high sensitivity in the conditions of the Western Forest-Steppe of Ukraine. ‘Pogonych’ variety demonstrated ecological plasticity. Conclusions.‘Pogonych’ stem lettuce variety showed ecological plasticity, stability and tolerance to stressful environmental conditions in the Western Forest-Steppe of Ukraine, but it was less adaptive to the constant limits of soil and climatic parameters of environmental factors. High homeostaticity was inherent in all studied varieties, which had a higher, than 70% coefficient of agronomic stability, namely: ‘Pogonych’, ‘Cobra’ and ‘Tseltus’. |
