Growers can expect early aphid pressure to pose a threat to emerging spring crops in the coming weeks, after mild temperatures this winter.
Temperatures in January and February were higher than the long-term average throughout much of England, by about 1-1.5 degC, however temperatures in Scotland have been much nearer to the norm.
Mark Taylor of Rothamsted Research complies the AHDB aphid forecasts. He says: “Over the last 50 years, the mean January and February temperature has shown the strongest correlation with the timing and size of aphid migrations.”
As such, AHDB predicts aphid pests will fly two to three weeks earlier than average this spring.
Cambridgeshire agronomist Graham Richards says: “Early aphid movement is likely to pose a risk to early-drilled spring crops. The threat of barley yellow dwarf virus to cereals is something I would be most concerned about.
“Where aphid numbers are predicted to be high, I would suggest applying an aphicide to emerging spring cereals.”
Last December saw record-breaking temperatures, climbing to more than 4degC above the long-term average, making it the warmest December since 1934.
This caused increased late aphid flight activity and movement in many autumn sown crops.
Mr Taylor says: “The weather in December was extremely interesting and way outside anything experienced by the aphid forecasting team.
“We know the extreme cold snap in December 2010 had little influence on the first flights in 2011, but we wait with interest to see if the warm December causes the first flights to deviate significantly from those forecast.”
The first aphids are forecast to be caught in suction traps later this month, with the Starcross suction trap in Devon likely to supply the first evidence of aphid movement.
In addition to the suction trap network, the yellow water-pan trap network helps provide field-level aphid monitoring information in potato crops.
AHDB is calling for growers to get involved by having a trap in their fields, helps provide greater coverage across the UK.
Claire Hodge, AHDB Potatoes technical executive, says: “By signing up to our aphid monitoring service, you will receive information on the aphid species present in your area, helping you gauge the risk to potato crops.”