Title : Application timing and concentration of abscisic acid to improve color of new hybrid ‘BRS Isis’ table grape in double cropping pattern
BRS Isis’ is new hybrid colored table grapes grown in Brazil. However, the lack of a pink and uniform color of berry skins is observed when this cultivar is grown in warm climates, with double cropping pattern, the high temperatures may inhibit anthocyanin accumulation. The endogenous plant growth regulator, abscisic acid (S-ABA), the concentration of which increases in grape berry skins at the onset of maturation (veraison), seems to be involved in the regulation of anthocyanin accumulation. Recently, an ef?cient S-ABA production method developed so that it can be used on crops, which led to the evaluation of different concentrations applied at or around veraison to colored table grapes. Thus, a trial was carried out during two consecutive seasons in a commercial vineyard of ‘BRS Isis’ table grape trained on an overhead trellis system, located at Marialva, Paraná state, Brazil. A randomized block design was used with five treatments and four replications, with five vines per plot. 1) Control (no application); 2) S-ABA at 200 mg L-1 at 7 days after veraison (DAV); 3) S-ABA at 400 mg L-1 at 7 days after veraison (DAV); 4) S-ABA at 200 mg L-1 at 7 days (DAV) + 200 mg L-1 at 14 days after first application (DAFA); and 5) S-ABA at 400 mg L-1 at 7 days (DAV) + 400 mg L-1 at 14 (DAFA). The exogenous use of S-ABA does improve the color of new hybrid ‘BRS Isis’ grapes, especially when it is applied twice, i.e., 400 mg L-1 7 days after veraison and 400 mg L-1 14 days after first application. Regardless of the concentrations or application timing, there is no alteration in the berries physical characteristics.