Fedorenko M. Improvement of the assortment of table grape varieties in Ukraine based on the assessment of a manifestation level of valuable traits in hybrid forms bred in the Institute of «Viticulture and Winemaking named after V. E. Tairov»

As a result of studying more than 50 characteristics of adaptability and productivity, genotypes with a stable, high level of manifestation of main valuable traits and exclusive properties of their berries were selected from 12 promising table grape hybrid forms. Agrobiological, phenological, immunological, and uvological characteristics of these 12 hybrid forms were studied. Extreme winter conditions in 2015 confirmed the high frost resistance and winter hardiness of new complex hybrid forms, while severe drought in recent years allowed us to objectively assess the susceptibility of plants to stress caused by the lack of soil moisture and make appropriate recommendations for their cultivation. Epiphytoties of fungal diseases (downy and powdery mildew) in 2017 allowed us to select hybrid forms with a high (not lower than relative) level of resistance. ‘Tairian’ and ‘Kalisto’ were determined as promising ones and will be used in the further breeding process. The study of the affinity of 12 scion-rootstock combinations of three promising table grape hybrid forms with four rootstock cultivars allowed to recommend grafting of new vigorous table genotypes on vigorous rootstock varieties ‘Dobrinia’ and ‘Kober 5BB’. These combinations showed the highest yields, the largest bunch and berry sizes, as well as higher adaptability due to increased plant viability. According to the results of this research, ‘Persei’ was included in the State Register of plant varieties for dissemination in Ukraine. They were propagated and transferred for testing to other grape producing regions of Ukraine.