LOQUAT FRUIT PHYSIOLOGICAL DISORDERS: CREASING AND RUSSETING
Incidence and causes of fruit physiological disorders were studied in Zaozhong No.6 and Changhong No.3 loquat. Russeting and skin creasing were the major disorders in both cultivars, while purple spot fruit were hardly found during the throughout fruit development. Zaozhong No.6 was more susceptible to russeting than Changhong No.3, and the fruit developed from late blooms in relatively higher temperatures were more susceptible than the fruit from early bloom. Zaozhong No.6 displayed a higher incidence of russeting (20%) than Changhong No.3 vs (7.5%). In Zaozhong No.6, "late" fruit had a higher incidence (25.9%) of this disorder than the "early" fruit (17.2%). In Changhong No.3, russeting incidence was 3.4% in the "late" fruit and 10.3% in "early" fruit. "Early" fruit had more cell layers and smaller skin cell size in the skin than "late" fruit in both cultivars, suggesting that skin cell size and cell layers, which are both affected by the duration of cell division, were associated with the incidence of russeting. Creasing affected 40% preharvest fruit in Zaozhong No.6, and the incidence was more severe in the "early" fruit than in the "late" fruit. Creasing was found to be a symptom caused by formation of abscission zone between the fruit base and the peduncle. Skin creasing was rarely seen in Changhong No.3, but fruit drop was severe. The incidence of skin creasing and drop, which were both caused by abscission, was coincident with spring flushing in both cultivars. With the maturation of spring shoots, the incidence of creasing and drop decreased. Hence, spring flushing might be the main cause of creasing and dropping before harvest.
Wang, L., Wang, H.C., Hu, Y.L. and Huang, X.M. (2007). LOQUAT FRUIT PHYSIOLOGICAL DISORDERS: CREASING AND RUSSETING. Acta Hortic. 750, 269-274
loquat, fruit disorder, fruit drop