FWI - 28th May 2015
Winter oilseed rape crops are being overwhelmed by turnip yellows virus (TuYV) this year, a new study says.
The nationwide survey, which was run by agrochem group Bayer and distributor Hutchinsons, found TuYV infection present in a mean average of 60% of winter crops.
The survey took samples from 75 plots in counties from all over England and Scotland.
The virus is a crop pathogen spread by aphids and can rob growers of up to 40% of their yield.
Bayer’s campaign manager Neil Thomson says the virus is now a major problem for growers in all areas of the UK.
“The survey results demonstrate all growers are at risk. I very much see TuYV as a hidden threat to oilseed rape growers as the symptoms are not readily recognisable and easily confused with nutrient deficiencies.”
He advises all growers to stay vigilant in late summer and early autumn and be ready to act as soon as aphids strike.
“Early infections are the most damaging so growers will need to monitor AHDB aphid bulletins and be prepared to spray as soon as they can be found in the crop.”
He adds that pyrethroids and pirimicarb sprays are ineffective because of high numbers of resistant aphid populations and recommends using a thiacloprid spray to give around two weeks protection.
A pymetrozine spray can be used later on if aphid numbers are particularly high.