Shoot Load Effect on Grapevine Productivity and Vigor

Abstract

The research was carried out in order to determine the effect of the number of shoots in the structure of bushes on their fruitfulness and annual growth, plant yield and grape quality. The work was carried out using generally accepted methods in viticulture in 2019-2021 in Rostov region. The scheme of the experiment involved the study of the following norms for loading bushes with shoots: 30, 35, 40, 45 pcs/bush. The experiment was carried out on own root plantations of phylloxera-tolerant grape variety Pervenets Magarach, planted in 1986. The feeding area of one plant is 4.5 m2 (planting pattern is 3 m × 1.5 m), the shape of the bushes is a two-sided horizontal cordon with a spare sleeve and a restoration knot (semi-covering). According to fruitfulness (95 and 94%), variants with a load of 30 and 35 shoots/bush, respectively, were identified; fruiting coefficient (K1) in both variants is 1.69. According to the size of the crop, a variant with 45 shoots per bush was selected - 17.0 t/ha with the highest quality of berry juice (mass concentration of sugars 17.9 g/100 cm3, titratable acids - 8.4 g/dm2. In the change in the content of sugars and titratable acids in the yield according to the variants of the experiment, no regularity was revealed, the difference in the value of this indicator is not significant. In terms of the productivity of one vegetative shoot, plants were noted in the variant with 40 shoots in the structure of the bush (178 g).The length of the shoots decreased with an increase in their number per plant from 90 4 cm in the variant with a load of 30 shoots to 82.2 cm in the variant with the maximum number of shoots in the experiment (45 shoots). No pattern was noted in the change in the diameter of the shoots, no significant difference was found between the options. The proportion of shoot ripening had an inverse relationship with their numbers on the plant.