Winter-hardy sweet cherry cultivars and forms of Nikita Botanical Gardens
In the Steppe Crimea the formation of archesporial tissue in the anthers of sweet cherry begins in the autumn, when the air temperature declines to 10-16°C. Flower buds stay in this stage all winter and have the highest winter hardiness at that time. But a short-term provocative thaw in the winter period can become a reason of significant damage of flower buds. We analysed the damage of sweet cherry flower buds as a result of critically low-freezing temperatures in January 2015 (-26°C). The aim of research was a selection of the winter hardiness sources for use in breeding and advancement in other climatic regions. The study included 29 cultivars mainly breeding of Nikita Botanical Garden and 36 intraspecific hybrid forms. Among 29 cultivars Drogana Zhyoltaya and Zarya Vostoka had received the least damage (no more than 28%). A significant degree of damage (among cultivars average 64%) could be a result of the warm winter period before the temperature dropped to a critical value. Among studied hybrids 4 forms had received significantly less damage of flower buds (no more than 21%) compared with control cultivars: 300 (9%), 453 (17%), 537 (21%), 602 (21%). Forms of early and medium ripening had received the average damage of flower buds at 67-69%, and forms of late ripening no more than 40%.
Tarasova, E.V. (2019). Winter-hardy sweet cherry cultivars and forms of Nikita Botanical Gardens. Acta Hortic. 1242, 931-936
winter hardiness, damage, flower buds, low temperatures