Wheat Bulb fly plant invasion started

By Jo Palmer

08 february 2012

This weeks Dow AgroSciences Pestwatch report shows that Wheat Bulb fly egg-hatch is still progressing in East Anglia and Lincolnshire and that there has been some initial plant invasion at the Suffolk and Lincolnshire sites.  There has been no egg-hatch at the Yorkshire site or in Scotland as yet.  It is anticipated that egg hatch will progress even more rapidly once the cold snap is over.

Issued weekly by Dow AgroSciences and ADAS, Pestwatch reports on the results of soil sampling at a number of sites across the UK and provide advice on the timely application of the soil insecticide Dursban WG (chlorpyrifos). Weekly information can be accessed at http://www.dowagro.com/uk/cereal/pest.htm . Week-ending the 2nd February 2012, Wheat Bulb fly egg-hatch in Suffolk was reported to be 38.5%, in Cambridgeshire/Hertfordshire on mineral soils was 28.3%, North Lincolnshire (a new site for 2012) on mineral soils 7.43% and in Cambridgeshire on organic land was 29.1%.

Sarah Hurry of Dow AgroSciences explains that fields at risk, particularly in East Anglia and Lincolnshire, may need treatment with Dursban WG at the first opportunity as tiller survival is important.  “This application should be active for 5 to 6 weeks on mineral soils. Dursban WG can be applied to frosty ground, but should not be tank-mixed.Avoid applications to frozen soil where rain could result in run-off to water courses.”

An interval of 14 days needs to be observed between applications of Dursban WG and GF-2070 or Broadway Star, regardless of weather conditions. For approved formulations of iodosulfuron-methyl-sodium and mesosulfuron-methyl, a longer interval of 4 weeks is required for crop safety reasons.