Indole-3-butyric acid, an alternative to GA3 for bunch quality enhancing of table grape Vitis vinifera L. cv. Superior Seedless

PUGLIESE, B.; GUZMÁN, Y.; PACHECO, D.; BOTTINI, R.; TRAVAGLIA, C.; AVENANT, J.A.; AVENANT, E.; BERLI, F.

REVISTA DE LA FACULTAD DE CIENCIAS AGRARIAS DE LA UNIVERSIDAD NACIONAL DE CUYO

UNIV NACIONAL CUYO

Lugar: Mendoza; Año: 2022 vol. 54 p. 163 - 174

0370-4661

Gibberellic acid (GA3) is the most widely used plant growth regulator to thin out bunchesand increase berry size in seedless table grapes, but there is evidence of its negative effects,including loss of fertility and malformations of the rachis. This study analyses the effects ofapplying the auxin indole-3-butyric acid (IBA), as a novel alternative, on fruit yield, bunchstructure, anatomy and postharvest quality of cv. Superior Seedless. The application ofIBA and GA3 at different phenological stages (15 cm shoot length, full bloom, fruit set andpea-size berry) and doses (2, 20 and 50 ppm) were compared in a two-growing seasonexperiment. Spraying IBA at full bloom or fruit set, improved bunch weight by increasingthe size and weight of the berries, correlating with the promotion of rachis vascular tissues.Bunches treated with IBA retained a greater number of berries at harvest without generatingcompactness, since the elongation of the rachis internodes and lateral shoulders were alsopromoted. In addition, IBA augmented postharvest quality of bunches by reducing rachisbrowning and increasing berry firmness. These results suggest that the use of IBA is abeneficial technology to improve bunch structure and quality in seedless grapes.