Developing ethyl formate treatment for disinfesting pipfruit

Abstract

Mealybugs, scale insects, thrips and apple leafcurling midge (ALCM) on packed New Zealand apples are a concern for export markets, and there is interest in 'soft'technologies to remove insects in postharvest treatments. Ethyl formate (EF) is a Generally Recognised As Safe (GRAS) plant volatile compound, which was used in trials to reduce pest incidence on apples to acceptable rates for export markets. A treatment of 0.3% EF (+CO2) for 1 h controlled 99% of onion thrips and latania scale, and 0.81% EF (+CO2) for 1 h controlled obscure mealybug. Treatment concentrations and times required to control ALCM (4.94% EF for 4 h) was beyond the apple quality tolerance level. Further research is required to determine apple quality tolerance levels, other market access pest EF concentration mortality responses, sorption rates of different apple cultivars and effect of temperature on pest mortality and fruit responses.