New restrictions on the insecticide dimethoate may reduce the availability of blueberries in Australia as growers adjust their fruit fly management strategies. The Australian Pesticides and Veterinary Medicines Authority (APVMA) has suspended the use of dimethoate due to concerns about safe exposure limits.
Aman Lehl, who produces blueberries, raspberries, and blackberries at Corindi Beach on the New South Wales Mid North Coast, said dimethoate was the only product that directly controlled larvae already inside the fruit. "Dimethoate was the only chemical that was known to actually kill the maggot that was inside the fruit," he said. "Everything else can target different stages, like the adults that are flying around, but nothing really targets that maggot that's already infested the fruit."
Manufacturers are able to apply for variations to their registration that would allow growers to use the product if they maintain a 14-day interval between application and harvest. Lehl said the requirement is impractical. "In the summer, it's just too long, you're going to have overripe fruit, you're going to be losing your fruit anyway."
He noted that the impact on yields will depend on seasonal fruit fly pressure. "Fruit fly pressure varies from one season to the next, so in a season with high pressure, the alternative strategies aren't all that successful. In those years, it's quite possible that it could have a massive impact on yields."
Growers are now looking to alternative methods such as lure traps and bait sprays. Lehl said an adjustment period is expected. "Growers will be nervous, but growers have to adapt to a hundred challenges. Every season is always something new, growers know how to adapt, and this won't be any different." He added that prevention will become more important. "Many growers have already been doing that for the past eight to 10 years and relying minimally on dimethoate anyway. As long as they can keep the fruit fly away, it won't have an impact on fruit quality."
Lehl said he does not expect any decline in quality on the market. "If growers get an infestation, that fruit's not marketable, so the consumer won't see that bad quality fruit."
The New South Wales Food Authority stated that routine sampling and compliance checks continue. A spokesperson said a recent joint review with the NSW Environment Protection Authority "showed there is no evidence that blueberries are unsafe to eat." The authority recommends washing fresh fruit and vegetables with cool tap water before consumption.
Source: ABC News
