Wheat Bulb Fly

Wheat Bulb Fly

Final Report: 2nd March 2012

In support of product stewardship of Dursban* WG, Dow AgroSciences in conjunction with ADAS, will be monitoring Wheat Bulb fly egg-hatch and subsequent plant invasion. This helps farmers comply with needs to accurately assess risk and thus optimize spray timings.

Results of the HGCA-funded survey of Wheat Bulb fly egg numbers in England show 20% of fields sampled are above 250 eggs/m². In Scotland from sampling conducted by Scottish Agricultural Colleges, the risk is considered to be low-moderate; here 30% of fields had Wheat Bulb fly populations that exceeded 100 eggs/m².

From this survey, fields in the main risk area have been selected which have high or very high egg numbers present. Progression of egg-hatch will be monitored weekly between now and mid-February.

Results

Egg-hatch is progressing now at all sites. The SAC have also confirmed egg-hatch at similar levels in Scotland, to those Yorkshire.

There is plant invasion of Wheat Bulb fly in East Anglia and Lincolnshire, although all larvae are still at first instar.  There is no plant invasion yet in Yorkshire.

What does this mean for you?

It is now too late for an egg-hatch spray in East Anglia and Lincolnshire. In the North and in Scotland, for at risk fields, apply Dursban WG at the first available opportunity as tiller survival will be very important.

In the absence of egg counts for specific fields, risk assessments for treatment must be made on basis of locality, previous cropping, drilling date, plant population, tillering and soil type. Use Risk Assessment Charts to identify fields at risk.

Be prepared to apply Dursban WG at 1.0 kg/ha in 200 to 1,000 litres per hectare of water.

In the event of a prolonged egg-hatch a repeat application of Dursban WG may be required, particularly on organic soils.

If necessary, Dursban WG can be applied to frosty ground but should NOT be tank mixed.  Do not apply to frozen soil where rain could result in run-off to water courses.

Equity* also has recommendations for Wheat Bulb fly.

Learn more about Dursban WG.

Learn more about Equity.

Use low drift nozzles and extend buffer zones to preserve Dursban WG use!

When spraying Dursban WG or Equity for wheat bulb fly:

• Use LERAP – low drift – three star nozzles

• AND adopt a 20 metre no-spray buffer zone (1 metre for dry water bodies)

Have a look at the video on www.saynotodrift.co.uk/arable/ of spraying with these nozzles versus conventional flat-fan applications.

Use plant protection products safely. Always read the label and product information before use. For further information including warning phrases and symbols refer to label.

Dursban and Equity are trademarks of Dow AgroSciences LLC. All other brand names are trademarks of other manufacturers for which proprietary rights may exist.

Dursban WG contains chlorpyrifos. Equity contains chlorpyrifos.