Evaluation of exclusion netting for insect pest control and fruit quality enhancement in tree crops

Various types of net canopies are now widely utilised for a range of horticultural crops in Australia to provide protection from birds, bats, hail, wind, frost and sunburn damage. However, to date, there has been very limited use of netting to provide additional protection from insect pests. Fruit flies (Bactrocera spp.) are major economic and quarantine pests in many parts of Australia requiring rigorous preharvest and postharvest control treatments to be applied to susceptible crops to meet market access requirements. This research demonstrated that exclusion netting (full enclosure - 2mm mesh) could provide the benefits of conventional net protection as well as effective control of fruit flies in low-chill stone fruit, a highly susceptible crop. Environmental and crop growth parameters under exclusion netting and under conventional bird and bat netting were measured. Exclusion netting increased maximum temperatures by 4.4°C and decreased minimum temperatures by 0.5°C. Although exclusion netting reduced irradiance by approximately 20%, it enhanced fruit devel¬opment by 7-10days and improved fruit quality by increasing sugar concentration by 20-30% and by increasing colour intensity by 20%.