USING LEVELS OF KIWIFRUIT SEPALS AND STEM ENDS COLONIZED BY BOTRYTIS CINEREA TO PREDICT GRAY MOLD IN STORAGE

A field-monitoring method involving colonization of fruit sepals and stem ends by Botrytis cinerea has been developed that can predict the incidence of kiwifruit Botrytis gray mold in cold storage.
The method simply consists of sampling 60 fruit from vineyards 4 months after fruit pollination, plating their sepals or stem ends in petri plates containing acidified potato-dextrose agar, and recording the incidence of Botrytis colonization.
The incidence of B. cinerea colonizing the sepals or stem ends collected 3 or 4 months after fruit pollination is a good predictor (r ≥ 0.95) of the levels of Botrytis decay after 3 and 5 month storage.
Preharvest spray(s) with vinclozolin (Ronilan 50WP) one and/or two week before harvest, respectively, significantly reduced postharvest gray mold after 5 months storage only in a vineyard with more than 6% incidence of gray mold while preharvest sprays were not needed when the incidence of gray mold was lower than 6%. The developed method for predicting Botrytis gray mold in storage can be used to make decisions on the need for preharvest sprays, sorting during storage, re-packing, marketing, and shipping fruit.

III International Symposium on Kiwifruit

T.J. Michailides, D.P. Morgan

https://doi.org/10.17660/ActaHortic.1997.444.108