High pressure air for pest removal from kiwifruit

Insect removal from kiwifruit is important for improving access to overseas markets. Insect removal from kiwifruit by physical treatments such as high pressure washing is hugely successful but kiwifruit packing is carried out “dry”. Therefore, one potential option is the use of ‘air-knife’ blowers to remove insects. A system with air-knives from the sides and top that was mounted over a single-lane Compac grader was able to remove over 90% of artificially inoculated diapausing two-spotted mites (≈ 85/fruit). The difference in pest levels between untreated ‘Hayward’ kiwifruit fruit naturally infested with a wide range of insects (n=2194) and fruit exposed to air-knives (n=2204) was: mealybug 100%, beetle/weevils 91—100%, oribatid mites 93%, tuckerellid mites 98%, unidentified mites 88% , booklice 86%, thrips 74— 100%, Collembola 63%, cockroaches 100%, spiders 43%, scale insects 40%. Air-knives had no noticeable effect on ‘Hayward’ or ‘Zesy002’ (Gold3) fruit quality. These results indicate that air-knives using a high air-flow/low-pressure system can effectively remove high rates of “mobile” insects and first-instar scale insects, and can probably be implemented logistically and economically from a commercial perspective.