Dimethoate ban sparks fruit fly fear

UPDATE: IRRADIATION could become the treatment of choice for Queensland fruit fly.

Dimethoate, a key chemical used for both pre-harvest and post-harvest control of the harmful pest, was last week suspended by the Australian Pesticide and Veterinary Medical Authority.

The APVMA ordered a 12-month ban on the use of chemicals containing dimethoate on dozens of vegetable and fruit crops, as well as ornamental plants and flowers.

The ban also prohibits its use on all food-growing plants in home gardens.

AusVeg spokesman Andrew White said the vegetable industry was considering a number of alternatives for fruit fly control.

Mr White said trichlorfon and maldison were as effective as dimethoate when used pre-harvest, but were significantly more expensive.

''For post-harvest treatment there's not really any silver bullets at this stage,'' he said.

''The effect on the industry is likely to be quite significant.

''We understand that irradiation is an emerging technology that may have some potential and that's being considered.''

Mr White said Food Standards Australia New Zealand had approved irradiation as a phytosanitary measure for lychees, mangoes and papaya.

The technology had been shown as a publicly accepted commercially viable option for mangoes exported to New Zealand, he said.

The suspension was foreshadowed in August when the APVMA issued a show-cause notice to the industry after an assessment found residues on many crops exceeded the new public health standard established in January.

Farmers can still use dimethoate on a range of horticulture produce - mostly those with inedible skins - and stock feed crops as long as they abide by instructions for use and withholding periods.

Tasmanian Farmers and Graziers Association chief executive officer Jan Davis said that suspension of dimethoate posed a "a serious biosecurity risk to Tasmania's clean and green status".

"The chemical is predominantly used in the control of (Queensland) fruit fly on the mainland," Ms Davis said.

"Tasmania is free of fruit fly and we want to keep it that way.

"The risk of a fruit fly incursion will be heightened as dimethoate is the most effective available treatment."

Australian Table Grape Association chief executive Jeff Scott said the industry would battle through this summer thanks to the registration of an alternative, trichlorfon, for use on table grapes in all states.

But that was only a stop-gap measure and Mr Scott said a cross-industry project by Horticulture Australia was needed to find alternative chemical treatments that would satisfy the APVMA and other health standards.

"It needs to happen sooner rather than later," he said.

Apple and Pear Australia communications manager Stuart Gray said dimethoate was no longer widely used in the pome fruit industry.

Mr Gray said that there were permits pending for other products, including spinetoram, but cold treatment also was an effective quarantine measure against fruit fly.

Queensland peak horticulture body Growcom has worked feverishly to encourage grower groups to address the issue.

• More information is available from the APVMA by calling (02) 6210 4749 or at www.apvma.gov.au