Spray with plant growth regulators at full bloom may improve quality for storage of 'Superior Seedless' table grapes by modifying the vascular system of the bunch

YANINA GUZMAN; MARÍA BEATRIZ PUGLIESE; CARINA GONZALEZ; CLAUDIA TRAVAGLIA; RUBEN BOTTINI; FEDERICO BERLI

POSTHARVEST BIOLOGY AND TECHNOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2021

0925-5214

The quality traits of table grape most appreciated by the consumers are berry size, bunch architecture, andfreshness appearance (especially after post-harvest cold storage). Loss of bunch freshness reduces the valueand selling potential for the market. Application of plant growth regulators (PGRs) may improve quality,particularly in seedless cultivars that naturally set compact bunches with small berries. PGRs as auxins andgibberellins are involved in fruit set, growth, development and ripening processes, including vascular tis-sues differentiation. This study aimed to determine if the combination of auxin indole-3-butyric acid (IBA)and gibberellic acid (GA3) improve quality attributes of ´Superior Seedless´ bunches. Field grown vineswere sprayed at full bloom, with 20 mg L−1IBA and 20 mg L−1IBA +10 mg L−1 GA3, to evaluate their ef-fects on bunch quality at harvest and post-harvest (after 60 d of cold storage; 0 °C and 95 % RH). IBA + GA3treatment produced looser bunches with larger berries as compared to Control. Total vascular bundle area(xylem and phloem) and rachis hydraulic conductivity were increased by IBA + GA3. As well, IBA + GA3improved rachis and berries firmness, also freshness appearance after 60 d cold storage. In conclusion, asingle spray of IBA + GA3 at full bloom improved quality and cold storage capacity of ?Superior Seedless?table grape, but it is not clear if GA3 or the combination of IBA and GA3 contributed to the observed effects.