This work was an attempt to evaluate the trunk girdling effect on different periods to hasten the maturation of 'Rubi' table grape in the northwest of Parana state, Brazil. The following treatments were studied: Control without girdling; Girdling when total soluble solids (TSS) of berries ranged from 5-6 ºBrix; Girdling when TSS of berries ranged from 7-8 ºBrix; and Girdling when TSS of berries ranged from 9-10 ºBrix. A randomized block design with four treatments and five replications was used as an statistical model, and each plot was composed by one plant. Girdling consisted of removing a narrow ring of bark entirely round of the trunk using a double-bladed 3.1 mm knife, 1.5 m far from the ground. Total soluble solids and titratable acidity (TA) were evaluated weekly through berries samples collection, from the establishment of the experiment up to its harvesting. Through regression analysis, it was estimated the advanced fruit ripening period of each treatment considering the index of maturity TSS/TA = 20. The highest period of advanced fruit ripening was observed when girdling was realized when TSS of berries ranged from 5-6 ºBrix, i.e., 8 days. There was no difference in relation to the cluster and berry physico-characteristics between treatments.
Vitis vinifera; grapevine; soluble solids; titratable acidity
