Wheat Bulb fly egg hatch progressing rapidly

This weeks Dow AgroSciences Pestwatch report shows that egg-hatch is progressing in East Anglia, particularly rapidly in Suffolk. There has been no change in egg-hatch in Lincolnshire and, as yet, no start to egg-hatch at the Yorkshire site.

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. Weekly information can be accessed at www.dowagro.com/uk/cereal/pest/htm. Week-ending the 26th January 2012, Wheat Bulb fly egg-hatch in Suffolk was reported to be 36.8%, in Cambridgeshire/Hertfordshire on mineral soils was 8.3%, North Lincolnshire (a new site for 2012) on mineral soils 2.3% and in Cambridgeshire on organic land was 10.9%.

Sarah Hurry of Dow AgroSciences explains that fields at risk, particularly in East Anglia and Lincolnshire, may need treatment with Dursban WG (chlorpyrifos) at the first opportunity as tiller survival will be important. “In the absence of prolonged cold weather, this application should have activity over the next 5 to 6 weeks on mineral soils. In the event of a prolonged egg-hatch, a repeat application may be required, particularly on organic soils. No start to egg-hatch at the Yorkshire site as yet suggests application timing is not such a priority in this area in the short term.”

She reminds growers that Dursban WG can be applied to frosty ground, but should not be tank-mixed. “An interval of 14 days must 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.”

Growers must also make sure that that they take all precautions to prevent drift by using low drift nozzles and an extended buffer zone when applying Dursban WG. The industry Stewardship initiative â€" Say NO to drift!- has the aim of protecting future availability and use of insecticides containing chlorpyrifos. When spraying Dursban WG for Wheat Bulb fly, growers must use a LERAP rated 3 star nozzle and adopt a 20 metre buffer zone near to watercourses or a 1 metre near to dry ditches.

For further information of Say NO to drift, please go to the web site at www.saynotodrift.co.uk where all the details are explained. On this site there is also a video to show showing spraying with low drift nozzles versus conventional flat-fan applications.

Dursban WG (75% w/w chlorpyrifos formulated as a Water Dispersible Granule) is recommended for the control of Wheat Bulb fly as well as Leatherjackets, Frit fly and Wheat Blossom Midge. For Wheat Bulb fly, two applications at dose rates of 1 kg/ha maybe applied up until flag leaf sheath extending (GS 39). It is packed in a 1 kg pack.