Gout fly on the move, warn advisors
8 October 2001
Gout fly on the move, warn advisors
By Tom Allen-Stevens
CEREAL growers in the east could be faced with a new pest problem this year, a leading agrochemical warns distributor has warned.
Essex-based agronomists from Farmacy have noticed the tell-tale signs of gout fly in crops of winter wheat.
“Theyve been a problem in the south west for a long time,” the companys technical services manager Jim Butchart told FWi on Monday (8 October).
“We dont know why, but they now seem to be coming into this area and are worth taking note of. They could be on the move.”
Mr Butchart advises growers to be on the look out for white eggs laid on the underside of leaves, although yield penalties from the pest are not severe.
But there could be an increased threat from Barley Yellow Dwarf Virus (BYDV), following the higher early-drilled acreage this year.
Crops drilled in early September and protected from the carrier aphids with an imidacloprid seed dressing will now be vulnerable, says Farmacys Robert Jack.
“The dressings become diluted as the chemical has to cover a greater amount of foliar vegetation and only last about six weeks at normal seed rates,” he says.
“The earlier the crop was drilled, the bigger the threat from aphid populations. Im certainly finding aphids in crops very easily.”
With the continuing mild weather, the risk of aphid flight into emerging crops is high and he suggests prompt action to avoid severe yield and quality penalties.
“I would advise growers to apply a pyrethroid spray in any crop where they are found.”
Only those leaves emerged at the time of spraying will be protected, he warns, so repeat applications are likely to be needed for later emerging leaves.
“Most growers are used to applying one pyrethroid, but those new to early-drilling might get caught out if they dont consider a second dose.”
Such chemistry will also tackle gout fly, which is not worth spraying for on its own, says Mr Jack.
Gout fly larvae attack the base of wheat and barley crops, stunting plants at tillering and killing seedlings altogether.
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