Keywords
Abstract
The effect of plant growth regulators Gibberellin, Zircon and Epin-extra on mechanical composition of the bunch, cropping capacity and sugar content in the juice of berries of three table grape varieties in the conditions of Pridnestrovie was studied. The influence of physiologically active substances on changes in the bunch weight, number of berries per bunch and cropping capacity depending on the meteorological conditions of the year was determined. It was found that in the more humid conditions of 2019 (HTC of 1.0), the bunch weight increase in experimental variants in comparison with the control plants was from 24.5% to 43.5% in ‘Zolotoy Don’ grape variety, and from 48.4% to 81.0% in ‘Velika’ grape variety. In the less moisture-rich 2020 (HTC of 0.6) this exceeding was at the level of 53.3%-110.3% and 17.7%-41.7%, respectively. An increase in the bunch weight of grape varieties treated with plant growth regulators is mainly observed due to an increase in the number of berries. It was found that two-fold treatment of plants with physiologically active substances leads to a significant decrease in the berry index and an increase in the index of grape bunch structure. The best variant for two-fold treatment of plants is Zircon, 0.6 ml/l, - for ‘Zolotoy Don’ variety; Epin-extra, 3.2 ml/l, - for ‘Velika’ grape variety in more humid conditions of 2019, resulting in the increase in cropping capacity of bushes by 46,7% and 81.1%, respectively. In the arid conditions of 2020, the treatment of ‘ Zolotoy Don’ variety with Epin-extra at a concentration of 3.2 ml/l and ‘Velika’ variety with Zircon, 0.6 ml/l, was the most effective, increasing the yield by 1.5-2.0 times compared to the control.