A test was conducted at Lubbock, Texas to determine whether phosphine would control pink bollworm larvae in bulk cottonseed. A dosage rate of 45 aluminum phosphatide tablets per 1,000 cubic feet was used to fumigate two large stacks of bulk seed totaling approximately 160,000 cubic feet. The stacks were covered with 1. 5-mil polyethylene sheeting. The cottonseed was under fumigation for 120 hours. The results indicated that the dosage rate of 45 tablets per 1,000 cublic feet, though effective, was minimum. Consequently, a dosage of 60 tablets per 1,000 cubic feet was recommended to, and accepted by, the Plant Pest Control Division for use in pink bollworm quarantine areas.