Морозо- та зимостійкість перспективних сортів абрикоса (Prunus armeniaca L.) в умовах правобережної підзони Західного Лісостепу України

Abstract

In the winter-spring period of 2019-2020 the researches were carried out on the territory of the Institute of Horticulture of the National Academy of Agrarian Sciences (IH NAAS) of Ukraine (the Kyiv region) under the field and modeled conditions in order to determine the influence of variable temperatures on the frost resistance and winter-hardiness of five apricot cultivars bred in Crimea (Nikitsky Botanical Garden). Cv Siaivo of IH NAAS was used as the control. The varieties estimation in the natural conditions showed that they were characterized with high winter-hardiness and frost resistance in all the variants of the experiment in the orchards. During the relatively cool winter of 2018/2019 with the minimum temperature -14,2°C the damage of the shoots tissues and buds were by almost two times more severe (all the strains) than in the nearly frostless winter of 2019/2020. When testing in the laboratory under t -25 °C the difference in the cultivars damage by years was not considerable, its general level being higher than in the winter period of 2018/2019 (in the control freezing was not utilized). At the same time under a temperature of -30 °C percent of the damage of most of cvs (5 out of 6) was higher in the winter of 2019/2020. That showed the importance of the cold influence on the plants preparation to the effect of low temperatures. The usage of such temperatures as -30 °C established the critical level of their influence on the varieties, especially on such tissues as the top and generative buds of the one-year increment. In the field conditions under the effect of the critical temperatures, namely: after the long thaw the plants could lose crop at all as their generative buds did not endured significant air temperature fluctuations which took place in the winter period of 2019/2020. However, with the proper management the trees could be restored after the stress influence, the crop losses being rather substantial though. It was the strain Vynoslivyi that appeared the most frost resistant and can be applied in breeding as one of the parental forms and grown in sufficiently great industrial volumes.