Assessment of resistance of grape varieties to mildew in the steppe zone of the Lower Volga region

Abstract

In the article the results of studying the peculiarities of mildew development by the macroscopic diagnostics method on the examples of 33 varieties and hybrid grapes forms in the conditions of the steppe zone of the Lower Volga Area have been reported. Indicators of the maximum infection of leaves, inflorescences and medium infection of vegetative and reproductive organs were characterized by the greatest degree of susceptibility to mildew. The degree of mildew’s distribution and development changed from year to year depending on the current year weather conditions and the features of its development in the previous year. During the seven-year period of observations three years were characterized by epiphytoties mildew. As a result of studying of grapes resistance to mildew, groups of irresistant, tolerant and resistant varieties have been distinguished.