Joy and Venus seedless grape cultivars in the lower Don Region

Abstract

In 2018-2022, a series of studies was conducted in the experimental plots of the Novocherkassk branch of Potapenko All-Russian Scientific Research Institute of Viticulture and Winemaking (Novocherkassk, Rostov Oblast) using conventional viticulture methods and GOSTs. A comparative study of the Joy grape, a new promising resistant seedless cultivar of the University of Arkansas (USA), and the Venus grape, one of the first seedless cultivars of the same institution, was carried out. The growing characteristics included the following: uncovered, unwatered, grafted, Berlandieri×Riparia Kober 5B rootstock, 3.0×1.5 m planting scheme, fan-shape formation on the middle stem. Agrobiological indicators, phenological observations, productivity, chemical and technological data, as well as tasting evaluations of fresh and dried grapes, are presented. During the study period, the preservation of buds in the Joy and Venus plants was 78.3 % and 80.1 %, respectively. Although the indicators of shoot fruitfulness and fruiting ratio were high in both cultivars, Joy showed a higher average weight of bunches and berries compared to Venus (311 and 282 g; 3.1 and 1.6 g, respectively). The yield was 13.8 t/ha and 12.4 t/ha, respectively. Both cultivars proved to be highly resistant to major grape diseases; in 2021, Joy grape bunches were slightly affected by mildew at the level of 2.5 points. The mass concentration (average for the study period) of sugars in Joy and Venus plants comprised 20.2 g/100 cm3 under the titratable acidity of 6.8 g/dm3 and 19.3 g/100 cm3 under the titratable acidity of 7.3 g/dm3, respectively. The conclusion is made that the studied cultivars present interest for cultivation as table wine and raisin varieties in areas with sufficiently moderate climate due to their high yield and seedless characteristics. These cultivars are recommended for possible expansion of vine plantations and further use in breeding.