THE IN-TRANSIT SHIPBOARD FUMIGATION OF SOYBEANS WITH PHOSPHINE PROBED2-3 METERS DEEP

Soybeans loaded in three holds of a bulk dry-cargo ship were fumigated with phosphine using Detia bags. Gas penetrated well to 12 to 15 m co ntrolling caged maize weevils Sitophilus zeamais, confused flour beetl es Tribolium confusum as well as the lesser grain borer Rhyzopertha do minica; however, at depths beyond 15 m to 23 m many insects survived w here the concentration times time (CxT) products were low. Mean temper atures did not change in the grain mass except in areas close to the w alls of the holds. Regardless of where grain samples were taken follow ing fumigation, residues of phosphine in soybeans remained well below 0.1 mg/kg.