The Exogenous Application of Abscisic Acid Induce Accumulation of Anthocyanins and Phenolic Compounds of the ‘Rubi’ Grape

The abscisic acid (ABA) is related to the formation of certain polyphenols, such as anthocyanin, improving the nutritional and commercial quality of the red grapes. In this study, we verified whether the exogenous application of S-ABA favors the accumulation of anthocyanin, the total phenolic compounds and the antioxidant activity of the ‘Rubi’ grape. The experiment was performed during the cycle 2014/2015 with the ‘Rubi’ vine (Vitis vinifera L.) grafted in the rootstock 420-A. The experimental design was composed of randomized blocks, with four treatments and six blocks, in a total of 24 experimental parcels, constituted of one plant each. We used the S-ABA isomer in different concentrations and times of application, 400 mg·L-1 S-ABA in the beginning of the ripening (BR); 400 mg·L-1 at BR + 200 mg·L-1 at 25 days after first application (DAFA); 400 mg·L-1at BR + 400 mg·L-1 at 25 DAFA; besides the control (0 mg·L-1). After 40 days of the first application, the samples were harvested and we verified that the S-ABA induced the accumulation of anthocyanins and total phenolic compounds in the ‘Rubi’ grape. From these results we can recommend two applications of S-ABA, 400 mg·L-1 at BR + 200 mg·L-1 at 25 DAFA.