Unique techniques developed in Israel for short- and long-term storage of table grapes. Issue 1 (2nd January 2016) - Lichter, Amnon
ABSTRACT: Gray mold caused by Botrytis cinerea and rachis browning due to desiccation are the two main factors that reduce table grape quality after harvest. For over 90 years treatments with the gas sulfur dioxide (SO2 ) have been in use to control decay. In Israel, two methods have been developed for grape storage: one for short-term storage and shipping, and one for extended storage of late ripening cultivars. The first is based on storage in cardboard boxes without liners, which shortens the forced air cooling time due to the reduction in packaging material. After cooling the pallets are wrapped around with linear low density polyethylene to contain the SO2 and the humidity. The second method involves storage in plastic boxes with modification of commercially available dual release SO2 pads, so that the pads release a continuous low rate of SO2 for a long period of over 4 months in cold storage. In this case as well, the pallet is wrapped on all sides in order to maintain the level of SO2 and high humidity. Moreover, for late season grapes, we established the efficacy of a postharvest disinfection treatment with ethanol in order to reduce the inoculum load before extended storage and to clean the grapes from accumulation of dust particles. These techniques allow prolonged storage for more than 3 months with minimal decay development combined with retention of grape quality.