Postharvest quality and health of kiwifruit ‘Hayward’ affected by Pseudomonas syringae pv. actinidiae

Abstract

Pseudomonas syringae pv. actinidiae (Psa) is the causal agent of bacterial canker of kiwifruit. The presence of Psa could affect the postharvest quality and health of fruit, which depends on the physiological state of the fruits and the techniques used for storage. In order to evaluate the effects of the presence of the pathogen on postharvest quality, the fruits from 12 orchards of Actinidia deliciosa 'Hayward', affected or not by Psa, were examined. Firmness, total soluble sugar (TSS), titratable acidity (TA) and postharvest rots were measured in different storage conditions, such as normal and controlled atmosphere, at three time points: at harvest, after 90 days storage, and in shelf life (after 120 days storage). The experiments were performed for two years. A further pre-storage treatment with 1-MCP was applied to evaluate the effects on fruit quality and storage. Significant differences between healthy and diseased samples were found for all the parameters analyzed. Fruits coming from diseased orchards showed lower firmness and TA values and higher TSS compared to healthy fruits. The fruits from diseased plants were much more susceptible to Botrytis rot. The results confirmed that the presence of Psa in orchards is associated to lower shelf life of kiwifruits and higher incidence of postharvest rots.