Oilseed rape (OSR) seed treated with neonicotinoids cannot be planted this autumn and foliar-applied pyrethroids will now be the main treatment option to protect OSR during the first 6-8 weeks of growth from CSFB attack.
But there have been reports of knock-down resistance (kdr) to pyrethroids in CSFB in Germany and suggestions from UK growers that pyrethroids are failing against CSFB in the UK.
Commissioned by HGCA, the research will investigate the issue. They will look to see if the kdr mutatuin is present in the UK CSFB population and from that calculate resistance. Growers are asked to send in CSFB populations to Rothamsted Research.
Dr Stephen Foster of Rothamsted Research said: “As we need good samples with a high number of live beetles, we are asking growers to sample around harvest because beetles are found in large numbers at this time.
“To help growers, we have produced some simple sampling guidelines which are available from the HGCA website.
Check out the sampling guidelines
“With many more growers considering pyrethroid applications this autumn as a consequence of the neonicotinoid restriction, it is essential that we all work together to understand and manage any potential resistance threat.”
The CSFB resistance project is part of a package of research commissioned by HGCA in response to the restrictions.
Other projects include a laboratory assay to test the potential of peach–potato aphids to transmit turnip yellows virus (TuYV) and how much shot hole damage OSR seedlings can tolerate so we can make sure growers are working with the best spray thresholds for CSFB.
IMAGE: © Alan Dewar, Dewar Crop Protection