Phosphine fumigation to disinfest kiwifruit
Global use of phosphine as a fumigant has increased in response to the need to replace methyl bromide, and with the improved formulations, ECO2FUME® and VAPORPH3OS®. Phosphine is registered as a postharvest fumigant on kiwifruit in New Zealand and has been used commercially to reduce the risk of detecting live pests. Scale insects, mealybugs and diapausing twospotted spider mites were exposed to a range of phosphine treatments. A 48-h low temperature (1.7-4.6°C) fumigation (6408-3311 ppm) achieved 100% mortality of all life stages of oleander scale insects, while a 12-h exposure killed all longtailed mealybug life stages. A 36-h low temperature (2.5-3.3°C) fumigation (4332-2712 ppm) treatment achieved 100% mortality of all greedy scale insect life stages. A 48- to 96-h treatment (3600-1200 ppm) at 1-15°C caused 91.3-100% mortality of diapausing twospotted spider mite adults. Use of phosphine as a commercial treatment for kiwifruit is discussed.