The Impact of Shoot Topping Intensity on Grape Ripening and Yield of 'Chardonnay'

Abstract

In recent decades, the negative effects of climate change have resulted in the premature ripening of grapes and thus inappropriate parameters of grape maturity. The dynamics of ripening and the quality of the grapes can be influenced via the process of topping the leaf wall height. The aim of the study was to analyse the impact of shoot topping intensity on grape ripening and yield parameters. The experiment was performed on the ‘Chardonnay’ variety in 2018. In the experiment, 540 vines were included and exposed to three treatments: control – shoot topping (length 120 cm), low-topping (length 50 to 60 cm) and notopping (without topping). The parameters of grape ripening (mass of 100 berries, sugar content and total acidity in grape juice) and grape yield were measured. The results of the study indicate, that leaf wall height has a significant effect on measured parameters of grape ripening and yield (P ≤ 0.05). The earliest ripening of grapes was found with the highest leaf wall (notopping). In this treatment, the maximum mass of 100 berries was also measured throughout the ripening period. In the lowtopping treatment throughout the entire period of ripening, the mass of 100 berries was lower, sugar content (°Oe) and total acidity (g/L) were also lower in grape juice compared to control and non-topped vines. A low-topping resulted in a lower grape yield. The results showed that the shoot topping intensity can slow down the ripening of the grapes and thereby reduce the negative effects of climate change.