Postharvest quarantine treatments of methyl bromide fumigation (MB) or a combination of MB and cold storage are allowed for the Mediterranean Fruit Fly (Ceratitis capitata) and other fruit flies. A study was undertaken to address the effect of MB on the fruit quality of `Hass' avocados. Fruit were obtained from two growers at a commercial packinghouse three times during the 1991 season. Fruit were fumigated at 21C or 30 C within 24 hours after harvest or after 1 week of storage. Fruit were evaluated after 0, 1, 2 or 4 weeks of storage at 5 C. Fruit quality was determined by flesh firmness, days to ripe, ease of peeling, weight loss, external discoloration, flesh or vascular discoloration and the presence/absence of decay. There was considerable variability between grower lots, however fruit that were fumigated had higher levels of weight loss, vascular or flesh discoloration and decay after 4 weeks of storage. The timing of fumigation had little effect on fruit quality. Generally, fruit which were fumigated at 30 C had less damage. These results suggest that `Hass' avocado could withstand MB as long as the fruit is marketed within 2 weeks of harvest.
M. L Arpaia, L. G. Houck, P. Hartsell, S. L. Ontai and J. S. Reints Jr.
J.L. Smilanick, F. Mlikota, P.L. Hartsell, J.S. Muhareb and N. Denis-Arrue
`Ruby Seedless', `Red Globe', and `Prima Red' table grapes were fumigated with the treatment schedule of the USDA-Animal Plant Health Inspection Service recommended for the control of mealybugs. Methyl bromide was applied at 64 g·m-3 (4.0 lb/1000 ft3) for 2 h at 16.1 to 18.3 °C (61 to 65 °F). The grapes were in commercial packages typical for each cultivar. After fumigation and 30 min of aeration, the grapes were stored 2 to 4 weeks at 5 °C (41 °F) and their quality assessed by evaluation of cluster rachis condition, shatter, berry cracking, decay, berry color, internal browning, bleaching injury, and firmness. None of the table grape quality parameters was significantly influenced by methyl bromide fumigation.
R.T. Hinsch, C.M. Harris, P.L. Hartsell and J.C. Tebbets
California nectarines [Prunus persica (L.) Batsch. var. nectarina (Ait) Maxim.] packed in single-layer corrugated fiberboard boxes were fumigated with methyl bromide (MB) at a rate of 48 g·m-3 for 21 hours at 21C and normal atmospheric pressure and a 50% load (v/v) as a quarantine treatment for codling moth (Cydia pomonella L.). When the boxes were loosely stacked with spaces between them or tightly stacked and forced-air fumigated, concentration multiplied by time (C × T) relationships were > 68 g·m-3·h-1, which is recommended for efficacy. Tightly stacked boxes that were not forced-air fumigated had C × T products <68 g·m-3·h-1. Organic bromide residues were <0.001 μg·g-1 and inorganic bromide residues were < 7.0 μg·g-1 after 3 days. A trace to slightly phytotoxic response was observed in `Summer Grand' and `Fantasia' nectarines in 1989 but not in 1990.
P.L. Hartsell, C.M. Harris, P.V. Vail, J.C. Tebbets, J.M. Harvey, V.Y. Yokoyama and R.T. Hinsch
Residues and the toxic effects of methyl bromide (MB) were determined in fumigation tests with six cultivars of nectarine [Prunus persica (L.) Batsch. var. nectarina (Ah.) Maxim.]. `Fantasia', `Firebrite', and `Summer Grand' were treated in wooden field bins in a commercial facility, whereas `May Fire', `May Glo', and `May Diamond' were fumigated in smaller fiberglass chambers. The treatment of 48 g MB/m3 for 2 hours at 21C and normal atmospheric pressure with a load factor of 50% (179 kg·m-3) was that proposed for quarantine eradication of the codling moth (Cydia pomonella L.). The appearance of the fruit, as well as the soluble solids content, were not affected by the MB fumigation; however, ripening of `May Grand' and `Firebrite' was delayed slightly. Sorption of MB was 55%. Desorption rates of organic bromide were not significantly different among the six treated cultivars; all fruits contained <0.001 μg·g-1 after 7 days of storage at 2.5C. Inorganic bromide residues in all treated fruits were <8.0 μg·g-1.