Abscisic acid (ABA) plays a major role in promoting ripening in sweet cherry, a non-climacteric fruit. Exogenous application of ABA has been performed to study fruit ripening and cracking, but this growth regulator is not used for commercial production. To determine the potential of this growth regulator to improve sweet cherry fruit quality, ABA canopy spraying was assayed in four cultivars. Canopy spraying of S-ABA significantly: (1) enhanced sweet cherry fruit color in ‘Glenred’, ‘Lapins’ and ‘Bing’ cultivars, but not in ‘Royal Rainier’ (a bi-colored cultivar), and (2) decreased fruit size and firmness in ‘Lapins’, ‘Bing’ and ‘Royal Rainier’. Seasonally reproducible effects were seen in ‘Lapins’ (mid/late-maturing) but not in ‘Glenred’ (early-maturing). Canopy spraying of nordihydroguaiaretic acid (NDGA) decreased color and increased fruit size in ‘Lapins’, but not in ‘Glenred’. Direct application of ABA on fruits attached to the tree, without application to the foliage, increased ‘Lapins’ fruit color without reducing size. These results suggest a localized fruit response to exogenous ABA application on fruit color development, but that a decrease in fruit size may be due to the effects of exogenous ABA on the tree canopy foliage.
Effect of Cold Treatment as a Post-Harvest Treatment for Killing Immature Stages of the Peach Fruit Fly, Bactrocera zonata (Diptera: Tephritidae) and its Effect on Fruit Quality of Pomegranate
