The management of phytopathogens plays a decisive role in the sustainable development of agriculture, especially in viticulture. A particularly serious impact is recorded in the development of pathogens of the vine, especially of powdery mildew (Uncinula necator (Schwein) Burrill). In addition to measures promoted by modern agricultural biotechnologies the particular interest are the epiphytic microorganisms, which populate the leaf surface of plants, constituting complex heterogeneous habitats from various extended communities and numerous transients from various systematic entities. Through effective management and control of plant diseases, crop losses can be reduced and the quality and quantity of agricultural products can be improved. The article includes the analysis of the role of different biotic and abiotic factors, which change the relationships within these communities, as well as the adaptation processes of some entities of epiphytic and phytopathogenic microorganisms on the leaf surface of the vine.
