‘Crimson Seedless’ is a table grape cultivar that often fails to develop adequate red color in Mediterranean climates. Application of abscisic acid (S-ABA) may be an aid for improving color, but its potential effects both on the overall quality and S-ABA concentration of the berry should be also considered. We tested two concentrations (200 and 400 mg/L) and different times of application (from one week after veraison up to nine days before harvest) of a commercial formulation of S-ABA (ProTone) in order to verify the effect on harvestable bunches, color, chemical characteristics, metabolic profile and S-ABA concentration in the berry. It was found that either the application of S-ABA at 400 mg/L one week after veraison or the application of S-ABA at 400 mg/L one week and four weeks after veraison positively affected the berry skin color shifting the hue (h◦) from 20 to a more red-violet hue (h◦=11-12). In general, the application of S-ABA, with the exception of the late treatments, enhanced coloration of the berries and increased the amount of harvestable bunches at the first pick because promoted the skin coloring process. S-ABA did not affect the berry firmness but reduced the berry detachment force. Nevertheless, the values remained sufficiently high and the general quality of the bunch was not compromised. Ripening parameters (°Brix, pH, titratable acidity) were not affected by S-ABA applications and even the primary metabolites profile was not influenced by the treatments, as ascertained by multivariate statistical analyses [Principal Component Analyses (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA)] applied to Nuclear Magnetic Resonance (NMR) data. The S-ABA concentration in the berry, when treatments were performed around veraison, was within the natural range for grape (10-400 ng/g f.w.), whereas when late treatments were applied (few days before harvest) the concentration was higher (more than 1000 ng/g f.w.). The best results for yield, quality and S-ABA concentration in the berry were observed for the treatments performed few days after veraison at the dose of 400 mg/L. This study gives new information about the positive effects of S-ABA on color with not particular change in the metabolic profile of the berry.
|Titolo:||Application of Abscisic Acid (S-ABA) to ‘Crimson Seedless’ Grape Berries in a Mediterranean Climate: Effects on Color, Chemical Characteristics, Metabolic Profile, and S-ABA Concentration|
|Data di pubblicazione:||2013|
|Digital Object Identifier (DOI):||10.1007/s00344-012-9316-2|
|Appare nelle tipologie:||1.1 Articolo in rivista|