Sussex grower David Taylor is planning to drill his winter wheat two weeks later than usual next autumn as he farms in a hot spot for an aphid-spread virus and a key seed dressing will then be banned.
He uses the neonicotinoid seed treatment clothianidin (Deter) on his farm in the South Downs just four miles from the sea as he is in a high-risk area for Barley Yellow Dwarf Virus (BYDV).
Yield losses from BYDV in winter wheat can be as much as 60%, and with the banning of neonicotinoid seed treatments, the only control will come from pyrethroid insecticide sprays.
Many growers, including Mr Taylor, are planning to delay drilling to limit their crops’ exposure to aphids and also destroy weedy stubbles or “green bridges” where aphids can harbour before attacking newly emerged cereals.
“We will try and delay drilling for as long as possible and also probably use a pyrethroid spray to control any aphids,” he told Farmers Weekly.
However, the scope to drill later is limited by the heavy clay caps on his downland farm and the need to get crops established before the winter’s hard frosts and eastern winds arrive.
This autumn Mr Taylor drilled 85ha of winter wheat and 45ha of winter barley between 20 September and 2 October, while next year he will delay drilling to the first half of October but he is not keen to drill after mid-October.
His crops are often through the ground in 10 days in mild autumns so he may be looking to use a pyrethroid at the two-leaf stage if the risk from aphids is high.
Avoiding pinched grains
He grows the milling wheat variety Zyatt, so is keen to avoid pinched grain from BYDV, which could downgrade his milling premium. The variety yielded 9t/ha in last summer’s dry weather against a long-term farm yield of 9-10t/ha.
Mike Thornton, head of crop production at agronomy group ProCam, says the neonic seed dressing gives about five to six weeks protection for crops, so without this product different tactics will be needed.
“There will be more attention placed on avoiding green bridges by using stubble cultivations and the use of glyphosate,” he said.
Mr Taylor farms around 500ha at Housedean Farm between Brighton and Lewes, and as well as 130ha of winter cereals, he grows oilseed rape, spring barley and grassland for a suckler herd.