Vitis labrusca grapes are widely cultivated in some countries such as Brazil and the United States, especially for juice production. ‘Isabel’ is one of the main cultivars because of its high production and disease tolerance, but the juice is deficient in color. The objective of this study was to evaluate the effect of timing and concentration of (S)-cis-abscisic acid (S-ABA), a specific isomer of abscisic acid applied to ‘Isabel’ grapes, aiming to increase anthocyanin accumulation and to improve juice quality. The trial was conducted on two consecutive seasons (2011 and 2012) in a commercial vineyard located in Maringa, PR, Brazil. The vines were trained in an overhead trellis system and spaced at 4.0 × 1.0 m. The statistical model used was a randomized block design with four replications and five treatments: control; S-ABA at 200 mg·L−1 at 7 days after veraison (DAV); S-ABA at 400 mg·L−1 at 7 DAV; S-ABA at 200 mg·L−1 at 7 DAV + 200 mg·L−1 at 15 days after the first application (DAFA); and S-ABA at 400 mg·L−1 at 7 DAV + 400 mg·L−1 at 15 DAFA. There were no significant differences between treatments in relation to berry or cluster size or weight. S-ABA application resulted in increased anthocyanin concentrations in both berries and juices, mainly when 400 mg·L−1 was applied. Sensory analysis also revealed the efficiency of this plant growth regulator to promote better acceptance of grape juices. Thus, a single application of S-ABA at 400 mg·L−1 at 7 DAV is sufficient to increase the anthocyanins concentration of ‘Isabel’ grapes, improving the acceptance of juice by consumers.
Renata Koyama, Adriane Marinho de Assis, Lilian Yukari Yamamoto, Wellington Fernando Borges, Rogério de Sá Borges, Sandra Helena Prudêncio and Sergio Ruffo Roberto
Renata Koyama, Ronan Carlos Colombo, Wellington Fernando Silva Borges, João Pedro Silvestre, Ibrar Hussain, Muhammad Shahab, Saeed Ahmed, Sandra Helena Prudencio, Reginaldo Teodoro de Souza and Sergio Ruffo Roberto
The application of S-ABA enantiomer to clusters of poor pigmentation cultivars can improve grape color. The aim of this study was to assess whether S-ABA applied to clusters of the new hybrid ‘BRS Melodia’ seedless grape can improve its color characteristics and to evaluate the consumer acceptance. The following treatments were evaluated: Control; S-ABA at 200 mg·L−1 7 days after veraison (DAV); S-ABA at 400 mg·L−1 7 DAV; S-ABA at 200 mg·L−1 7 DAV + 200 mg·L−1 21 DAV; and S-ABA at 400 mg·L−1 7 DAV + 400 mg·L−1 21 DAV. To apply the treatments, clusters were sprayed using a backpack sprayer until runoff. The exogenous application of S-ABA significantly improves the color of berries of ‘BRS Melodia’ seedless grape, particularly at a concentration of 400 mg·L−1 in two applications, at 7 DAV and 21 DAV, resulting in clusters with greater consumer acceptance through visual-sensory analysis. Regardless of concentration or application timing, there was no change in the physicochemical characteristics of the berries or clusters, nor in the number of shoots per cane or clusters per shoot in the season after its application.