PROCESSING tomato growers have been urged to treat crops with the pesticide dimethoate to guard against a Queensland fruit fly outbreak.

Already facing the prospect of crop damage from thrip and viral and bacterial diseases at higher than normal levels across northern Victoria and southern NSW, growers have been warned fruit fly could become an issue during harvest.

"To ensure all fruit can be readily harvested and moved for processing, it is recommended that all growers adopt a preventative pesticide spray program ASAP," an article in the latest industry newsletter said.

"It has been predicted once again that Victoria is currently facing one of the worst seasons for Queensland fruit fly outbreaks.

"Current quarantine zones have been declared around recent outbreaks in most of Victoria's key fruit-producing regions. If an outbreak occurs in the processing tomato production region, the movement of your fruit for processing could be hampered."

The Australian Pesticides and Veterinary Medicines Authority last October announced a 12-month suspension of the use of dimethoate on a number of food crops, including fresh tomatoes, owing to potential short-term dietary risks.

But dimethoate can still be used on processing tomatoes, with a minimum withholding period of 21 days in NSW, and 35 days in Victoria.

The only other product registered against fruit fly for use in tomatoes is trichlorfon, which costs about $90/ha for two applications, compared with $17.25/ha for dimethoate.

The APVMA is expected to complete further assessments on dimethoate this year.

Australian Processing Tomato Research Council industry development manager Liz Mann said this year's crop forecast was for about 223,000 tonnes.

"Crops at this stage appear to look good, with growers hoping that the rest of the season will provide favourable growing and harvest conditions."

Source - http://www.weeklytimesnow.com.au/