One of major concerns of modern agriculture is conservation, evaluation and utilization of genetic resources of agricultural plants. The aim of this research was to evaluate the resistance of leaves and berries of table grape varieties to powdery mildew (Erysiphe necator) under field conditions. During the period 1996-2004, 32 table varieties (viz. 28 interspecific varieties and 4 varieties of Vitis vinifera) were investigated. A high resistance of leaves and berries
to powdery mildew has been proved for varieties Augustovskii, Yalovenskii Ustoichivyi, Pőlőskei Muskotály and Pleven Ustoichyvii. It was also possible to confirm a lower degree of resistance to powdery mildew in some hybrids of V.vinifera x V. amurensis. Varieties of V. vinifera showed a low degree of resistance to powdery mildew infestation.
