Alternative fruit fly control for market access and to enhance IPM in eggplant
Queensland is a major supplier of eggplant to the Australian market, with the crop value estimated at around $20M annually. Over ninety percent of eggplant production is based in the Bowen, Burdekin and Bundaberg regions, which supply quality fruit to the domestic markets from March to December. The major domestic markets for Queensland eggplant are Sydney, Melbourne, Brisbane and Adelaide. Queensland fruit fly is regarded by quarantine authorities as a serious pest that can infest a wide range of commodities. And as such, any commodity regarded as a host to Queensland fruit fly is required to be treated before movement into markets such as Victoria, South Australia, Tasmania and Western Australia which are currently considered to be free of Queensland fruit fly. This project focused on gathering appropriate information to assist the future development of a new systems approach to fruit fly management in eggplant in order to enhance future market access. This research project gathered baseline data on fruit fly seasonal activity in Bundaberg, Bowen and Burdekin regions and examined the effectiveness of several alternate chemistry groups applied prior to fruit harvest. Multiple field trials and commercial fruit sampling conducted in the Bowen, Burdekin and Bundaberg production regions demonstrated that the pre-harvest cover sprays tested in this work combined with a rigorous pack-house grading processes can effectively reduced the risk of fruit fly infestation in eggplant to a low level. During the course of this project a total of 21894 fruit were collected from 5 trials on DAFF research stations and sampling from a commercial eggplant farm in Bowen. No infested fruit were recorded from fruit that was classified as commercial grade fruit. A total of 6 infested fruit were recorded from 1313 fruit that was classified as unmarketable or reject fruit from the Bowen trial site. In addition to this only a single infested fruit was recorded from the Bundaberg trials were 6394 fruit were sampled but not graded using commercial standards. The fruit fly monitoring program carried out as part of this project identified the fruit fly seasonal patterns in relation to the eggplant production period and clearly showed a ‘low fruit fly period’ from March to August. This demonstrates that eggplants grown during this period are at minimal risk of fruit fly infestation. Based on the results recorded during this project it is clear that current production systems with preharvest cover sprays (bifenthrin, abamectin and spinosad), pack-house sorting procedures and low fruit fly prevalence on eggplant farms does greatly reduce the risk of fruit fly infestation in eggplant.