Insurance OPs a threat to farmings new image

29 June 2001

Insurance OPs a threat to farmings new image

By Andrew Blake

INSURANCE use of organophosphorus pesticides risks undermining efforts to rebuild farmings public image, according to farmers weeklys south-west barometer farmer and his agronomist.

Two recent incidents highlight their concern. In the first, George Hosford, who farms at Travellers Rest, Blandford, Dorset, was advised to apply Actellic (pirimiphos-methyl) dust to the surface of stored naked oats to tackle mites immediately before delivery.

The second relates to a large local order of Dursban (chlorpyrifos) noted by agronomist Michael Madan-Mayers. "As far as I understand it was for a blanket spray against orange blossom midge on 5000 acres," he says.

Both represent poor use of the integrated crop management techniques vital to restoring consumers faith in modern agriculture, the men believe.

Mr Hosford says the suggested anti-mite dusting for his Lexicon oats destined for France via the Superioat company took little account of growing resistance to the insecticide.

"I dont like using it, but more importantly I dont believe it does for mites. I am not prepared to use something without knowing for certain that I need it.

"As a responsible grower I dont like pouring organophosphorus chemicals on crops, stored grain or sheep. In fact Id like to see them banned so we simply dont have the choice any more.

"The problem is that naked oats seem to attract mites like a magnet and keeping them cool enough to avoid trouble in June when the weather hots up is a problem.

"But quite frankly Id rather eat mites than Actellic."

Dursban is rarely used at Travellers Rest which is quite exposed and less prone to orange blossom midge attacks on wheat than other more sheltered farms in the area. "The last time we used it was about five years ago against leatherjackets after ploughing up some grass.

"Reports that there were blanket treatments going on against midge concern me very much. Its bad for our image."

Mr Madan-Mayers agrees but admits some agronomists are tempted to play safe and ignore advisory treatment thresholds when dealing with sporadic, but potentially devastating pests like blossom midge.

His inquiries suggested Syngen-tas pyrethroid Hallmark Zeon (lambda-cyhalothrin) was a more environmentally-friendly alternative to DowSciences Dursban. "I advised people to monitor their crops as suggested, and in most cases in the end we did not need to spray. You need an awful lot of flies buzzing about to meet the thresholds for treatment."

Although Hallmark Zeon has no label recommendation against blossom midge it clearly has activity against the fly and any exposed larvae, says Syngenta technical adviser Ian Stott.

Resistance on rise

Drying and cooling is the key defence against mites and mere turning of grain is usually enough to kill 95% of any present, says the CSLs Ken Wildey. The 4g/t application rate for Actellic, a relatively low toxicity OP is also "mind-bogglingly low", he adds.

Nevertheless unsolicited feedback from farmers and laboratory tests suggest that mite resistance to the chemical is widespread, says Dr Wildey. In some populations twice the recommended field dose has been required to achieve control. "In many cases it is just not working. But if a contract stipulates that it has to be used there is little a grower can do about it."


&#8226 Mites & blossom midge woes.

&#8226 Actellic & Dursban worries.

&#8226 More ICM input necessary?

&#8226 Public image issue.

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