The Tolerance of Imported Commodities to Fumigation with Methyl Bromide1

Abstract

In laboratory tests (1956–66) of various imported commodities, honeydew melons from Chile tolerated fumigation with methyl bromide at 64 mg per liter for 2 hours when the temperature was near 5.6 or 12.8 and the atmospheric pressure was normal (NAP), but some were injured by a rate of 48 mg per liter for 3.5 hours or 64 mg per liter for 3 hours at 12.8-14.4. Insect mortality tests with adults of confused flour beetles, Tribolium confusum Jacquelin duVal, which were inserted into the centers of the melons indicated methyl bromide penetration was slow but substantial. Seeds of Vicia faba L. tolerated 128 mg per liter for 7 hours NAP at 5.0 and 64 mg per liter for 2.5–4 hours at 660-mm sustained vacuum and 22.8–5.6. The Royal variety of apricots from the Union of South Africa tolerated fumigation NAP with 56 mg per liter for 2 hours at 23.3 or for 3 hours at 8.3, and the Barlenka, Waltham Cross, and Alphonse varieties of grapes tolerated 80 mg per liter NAP for 2 hours at 23.3 or 8.3. Also, varieties Emperor and Almeria grapes from Chile tolerated commercial fumigation under tarpaulin with 64 mg per liter for 2.5 hours at 4.4–6.1, and Rosaki grapes from Crete tolerated cold treatment for 12 days at 1.1 preceded by 2.5-hours fumigation with 48 mg per liter at 12.8 or preceded or followed by 56 mg per liter at 5.6. The keeping quality of Almeria grapes from Spain was poor after they received cold treatment for 16 days at 2.2 upon arrival, preceding or following similar fumigations.