Determination of Susceptibility of Some Hybrid Grapevine Genotypes to Powdery Mildew

The purpose of this study was to identify grape genotypes resistant to powdery mildew to reduce pesticide use in vineyards. A total of 70 hybrid genotypes from Narince x Regent and Narince Kishmish Vatkana crosses, along with four grape varieties (Narince, Regent, Kishmish Vatkana, and Isabella), were evaluated for their susceptibility to powdery mildew. Inoculations were carried out under controlled greenhouse and laboratory conditions between 2021 and 2022. The study assessed the severity of infection by measuring mycelium and sporulation density on the leaves. Results showed significant variation in susceptibility, with genotypes exhibiting differences in infection severity, ranging from resistant (Regent) to highly susceptible (Narince). Genotypes NRG-7, NRG-146, NRG-174, NRG-195, NRG-196, NRG-197, and NRG-200, as well as cultivars Regent, Kishmish Vatkana, and Isabella, showed resistance to the disease, while Narince was highly sensitive. These resistant genotypes have potential for use in organic farming, offering an opportunity to reduce fungicide applications and enhance sustainable viticulture practices.