Fruit growing
and viticulture of South Russia

Annotation

In the 2016-2017 the etiology of �summer� grape rots affecting Muscat Blanc grapes in conditions of the Southern coast of Crimea studied. These rots are becoming more and more important economically and can lead to the loss of up to 80% of the ripening harvest. It has been demonstrated that this phenomenon is a complex one and is caused by the development of such species as Botrytis cinerea Pers., Guignardia baccae (Cav.) Jasz., Aspergillus niger Tiegh., Rizopus nigricans Ehr., Cladosporium herbarum (Pers.) Link, Penicillium sp. It was established that sour rot prevails in the structure of berry rots affecting grapes by the harvest time (the third decade of August and the first and second decades of September). We studied how various affecting Muscat Blanc grapes berry rot pathogens depend on the temperature regime and berry juice sugar content. A strong correlation was established between the intensity of oidium development and damage to the grapes caused by thrips and the level of sour rot development. Laboratory and field experiments provided data on the biological effectiveness of modern specialized fungicides in controlling the development of grape rot pathogens. Fungicides application proved insufficient in preventing harvest loss of Muscat Blanc grapes from sour rot. To effectively control this disease, it is necessary to develop a separate set of measures, including those aimed at improving the mechanical strength of the grape berry skin, prevent oidium and herbivore thrips damage to the epidermis during berry growth, limit the development of fruit flies during the ripening of grapes.