The adaptability of summer apple varieties to climate changes in the Right-Bank Forest-Steppe of Ukraine

Abstract

Goal. To investigate new varieties of the apple of summer ripening and highlight those that have high adaptability to the conditions of Right-Bank Forest-Steppe of Ukraine in the period of the warming climate and may provide products of high consumer quality. Methods. Summer apple varieties (Papirovka (K), Early Gold, Mantet, Prystin) were studied in the period from 2011 to 2018 in the Kyiv region in the rain stand of the initial strain investigation. The stand was planted in 2010 with one-year trees on the rootstock 54–118 with the use of a planting scheme 4×3 m. Agrometeorological elements recorded during this period in the DAVIS station were also analyzed. Methods used: field, laboratory, comparison, statistical, generalization. Results. It is established that the tendency of growth of the heat supply of the vegetation period in the Kyiv region maintains stability in the last 8 years. The sum of active temperatures (389°C), which for many years fixed on the day of the ripeness of the apples the control variety Papirovka, significantly increased. The analyzed period was characterized by a lack of rains and frequent repetition of stress-factors. Under these conditions, the terms of blooming of the generative buds, beginning of flowering, ripeness of the fruits outrun the long-term average terms on 15±5, 12±4, and 16±7 days respectively. The studied varieties differed in resistance to bio- and abiotic factors (8.5–9.0 points) and were characterized by high early maturity (2nd–3rd year), non-stable fruiting, and different rates of increase in yields of trees in a young planting. Plants of variety Early Gold were more resistant to stress-factors of late-spring and summer periods in the Right-Bank Forest-Steppe. They annually formed intermediate or high fruit yield with the best consumer quality. Conclusions. Early Gold is a promising summer variety suitable for production tests in the Forest-Steppe of Ukraine. It is highly adaptive to the increased heat supply of the vegetation period and lack of rain. It can generate high-quality produce in conditions of significant climate change.