Although fumigation with phosphine is a simple technique, results, in terms of insect mortality, are often unsatisfactory. This is because complete insect control can only be achieved if an insecticidal concentration of phosphine is maintained for a sufficient length of time. Where multiple fumigations with phosphine have failed to meet these criteria insect resistance to phosphine has become established. This bulletin describes the formulations, equipment, application techniques and safety considerations required to achieve satisfactory fumigation results
