Ethylene dibromide fumigation of California-grown citrus: effects of fumigating unpacked, bulk fruits, or commercially packed fruits on applied dosage and residues

Two types of lemons and oranges were fumigate with ethylene dibromide (EDB): unpacked and unwaxed fruits in wooden picking boxes (bulk-treated) and commercially waxed and packed fruits in fiberboard cartons (packed-treated). By bulk-treating citrus fruits and eliminating the highly sorptive fiberboard carton material, the dosage of EDB applied was reduced by 43% (from 14 g/m super(3) to 8 g/m)) without reducing the exposure of the commondity to the fumigant. Residual EDB was found in the peel; relatively little was found in the pulp. The rate of desorption of EDB was significantly faster from bulk-treated, unwaxed fruits than from packed-treated, waxed fruits. The rate of desorption was also significantly faster from fruits stored at 18 degree C than from those stored at 6 degree C.