Influence of meteorological conditions on ripening of grape shoots in south areas of Western Siberia

Abstract

Introduced grape varieties were studied in the south of Western Siberia in order to identify the effects of unfavourable factors of the growing season on the ripening of grape shoots. Weather conditions in the south of Western Siberia during the vegetation periods 2012-2017 were characterized by large fluctuations in water and temperature conditions; there were sharp changes not only in different years, but also during one season. Compared with long-term average data, a significant increase of relative air humidity and the amount of precipitation was noted from May to September. In 2016-2017 sharp changes of the amount of precipitation by months were marked (dry June, over-moistened July). The most unfavorable weather conditions for grape crop were the conditions of the growing season of 2013 with excessive rainfall (410.3 mm), very low average monthly air temperatures in May, June, July, September and the sum of active temperatures (2031.7°C). Under the influence of meteorological conditions, the terms of the beginning of the studied phenological phase changed very significantly over the years (30-62 days). Shoots ripening in years with favourable weather conditions (2012, 2015) began from July 14-August 1, with unfavorable (2013, 2017) — September 11-15. In one grape variety, insignificant variability of the degree of the studied character was revealed by years, in two — medium, in eight — high. Shoots ripened better in warmer and less humid 2012 (66.8-94.1 %) and in 2015 (58.4-92.5 %). Varieties with very poor ripening (33.0-46.9 %) Arkady, Kodryanka, Tomaysky are unsuitable for cultivation under production conditions and recommended for cultivation in amateur gardens with additional shelter. Varieties with maximum ripening of shoots on average over the years were selected from the American group White Pearls, Latvian Pink (83.1-84.9 %), Amurian Adel, Vaskovsky Souvenir, Hasan Bousa (65.5-79.3 %).