THE INFLUENCE OF METHYL BROMIDE FUMIGATION ON THE STORAGE LIFE OF `HASS' AVOCADO

Abstract

Methyl bromide fumigation (MB) is allowed as a disinfestation treatment for fruit flies. A 2 year study was undertaken to examine the effect of MB on the storage quality of `Hass' avocado. Fruit were obtained from a commercial packinghouse in both years. In 1991, fruit were treated within 24 hours of harvest or after 1 week of 5C storage either at 21 or 30C (4 hr. aeration). In 1992, fruit were fumigated at 30C then aerated for either 2.5 or 5 hr. A comparison to a quarantine cold treatment (14 days at 1C) was included in 1992. Fruit were evaluated after 0, 2, or 4 weeks storage. In both years there was considerable variability between grower lots, however, fruit that were fumigated had higher levels of weight loss, decay, and external (1992 only) and internal discoloration after 4 wks. of storage. Neither the timing of fumigation (1991) nor the duration of aeration (1992) had a significant impact on fruit quality. Fruit held at 1C generally had less internal discoloration after 4 weeks than MB treated fruit.