Unique techniques developed in Israel for short- and long-term storage of table grapes

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.

KEYWORDS:

• Botrytis
• postharvest
• table grapes
• Vitis vinfera

Acknowledgements

The studies reported in this article were performed with the help of many people, some of whom are joint authors of the referenced papers. Special thanks to Tali Grapes, Guy Rozenfeld, Eyal Raban, and the many growers who helped in the studies.

Disclosure statement

No potential conflict of interest was reported by the authors.