Studies were begun in 1951 to develop a method of fumigating individual retail packages of beans or cowpeas on the packaging line by adding a small measured amount of fumigant to the filled package just prior to sealing. This was done to prevent infestation developing from insect eggs accidentally included in the package. An automatic dispenser was used to apply the measured dosage to each package. Thirteen fumigants were tested in laboratory tests on 1-pound cellophane bags and cardboard cartons. Six of the fumigants were tested on a packaging line under commercial conditions, and cellophane bags were used. Effective dosage of these selected fumigants ranged from 0.2 to 0.3 ml. per bag under packaging-line conditions at costs for the fumigant ranging from 23 to 49 cents per ton of commodity. Taste tests demonstrated no change in the flavor of cowpeas, and pilot tests with industry members revealed no adverse customer reaction.