Background: Neonicotinoid seed dressings on oilseed rape were banned in the European Union (EU) from December 2013. A survey of > 200 farms was conducted in England in the 2014/15 and 2015/16 seasons to assess the impact of the ban on changes in crop area, crop losses to cabbage stem flea beetle (CSFB), insecticide use and the economics of oilseed rape production.
Results: The area of oilseed rape grown fell in both seasons, with CSFB identified as the third most important reason for the decrease. Crop losses to CSFB were 3% and 5% in the respective seasons, with clear variation by county. There were clear differences in the crop area treated (1.14 vs 0.77 million ha) and the number of insecticide applications per crop (2.0 vs 1.4) to combat CSFB in 2014/15 and 2015/16, respectively. Within the derogation area counties there was a clear reduction in the number of applications per crop when neonicotinoid-treated vs non-treated seed was used (1.0 vs 1.9), respectively.
Conclusion: Increasing resistance to pyrethroid insecticides in combination with the neonicotinoid seed dressing ban is likely to have significant impacts on the viability of growing oilseed rape in England particularly where CSFB activity/risk is high. © 2018 Society of Chemical Industry.
Keywords: cabbage stem flea beetle (Psylliodes chrysocephala); financial cost; insecticide; neonicotinoids; oilseed rape (Brassica napus L.).
© 2018 Society of Chemical Industry.