Wheat Bulb fly - Update for Spring 2012

Saddle Gall Midge Survey - Calling all agronomists and farmers!

Advice for Blackgrass control with GF-2070 during December/January

Kerb Flo - Apply Now

This edition's FAQs:

- I've used Spitfire for volunteer bean control.  Can I come back with another application next spring? 

- Which ALS herbicides can follow GF-2070?

Picture courtesy of ADAS

Results of the HGCA-funded survey of Wheat Bulb fly egg numbers show 20% of fields sampled were above threshold with egg populations greater than 250 eggs/m².

A total of 41 fields were sampled in at-risk areas in England. Key points:

• 20% field above threshold of 250/m² compared to long-term mean of 23%
• Mean egg population is 179 eggs/m²
• 26 sites sampled in Eastern England.  Of these sampled fields:
  • 4% are in the very high infestation category (>500 eggs/m²)
  • 19% are in high or very high infestation category
  • 65% are in the moderate, high or very high infestation category
• 15 sites sampled in Northern England. Of these sampled fields:
  • 20% are in high infestation category
  • 60% are in the moderate or high infestation category
    • Watch out here! This is similar to last year (a bad year) and higher than in 2009/10 when the equivalent figure was 47% and is in marked contrast to 2007 when all sites were in the low category

Sampling conducted by Scottish Agricultural Colleges of 50 fields has found 30% had Wheat Bulb fly populations that exceeded 100 eggs/m². Key point:

• The risk for Scotland is low – medium

Treatment advice

• Treatment is recommended if the threshold of 250 eggs/m² is exceeded
• A lower threshold of 100-250 eggs/m² is appropriate for late November drilled crops (or in Scotland those drilled mid-October onwards) or winter-drilled wheat or spring wheat and barley crops

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.

Dow AgroSciences in conjunction with ADAS, will be carrying out Pestwatch monitoring of Wheat Bulb fly egg-hatch and subsequent plant invasion once again in 2012. This helps farmers comply with needs to accurately assess risk and thus optimize spray timings. High risk sites will be selected in Eastern and Northern England and the results of monitoring will be published in Pestwatch reports from mid-January onwards.

Dursban* WG provides good control of Wheat Bulb fly and protects crops from attack.

• Wheat Bulb fly can be a devastating problem
• Attacked crops are unlikely to yield their full potential
• Badly attacked crops could need re-drilling 
• Carry out a Risk Assessment on all crops believed to be at risk
• Dursban WG applications at egg-hatch eliminates the pest before it damages plants
• Dursban WG has a residual life in the soil which means that most larvae will be controlled as they hatch over a period of time

Equity* also has recommendations for Wheat Bulb fly.

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

Dow AgroSciences continue to invest in quality formulations of chlorpyrifos which can be relied upon by farmers. Not only is chlorpyrifos, the active ingredient in Dursban WG, vital in the control of Wheat Bulb fly, but is an important insecticide used for control of a wide range of key pests in many different crops.

Protecting the crop protection products we have available today is more important than ever. Dursban WG (chlorpyrifos) is the latest product to come under scrutiny from regulators.  A new ‘risk assessment’ for chlorpyrifos, under its routine EU/UK review, means that the existing label no-spray buffer zones adjacent to watercourses are no longer considered sufficient protection for aquatic organisms by the Chemicals Regulations Directorate (CRD). The criteria cannot be met by introducing larger buffer zones alone, meaning that low drift nozzles are now a necessity. An industry stewardship initiative – ‘Say NO to drift’ – has been unveiled by Dow AgroSciences, makers of Dursban WG, as part of a consortium with the two other chlorpyrifos approval holders.   The aim of this campaign is to protect the future availability and use of chlorpyrifos by advocating that it can be used with minimal risks to water provided 20m buffers are used in conjunction with a LERAP rated three star low drift nozzle. It is hoped that by demonstrating to regulators that as these nozzles are in widespread use and being used at the correct settings to deliver drift reduction then it should be possible to retain the product.

Learn more about “Say NO to Drift” for chlorpyrifos campaign.    

Details of LERAP rated three star low drift nozzles are available at: https://secure.pesticides.gov.uk/SprayEquipment/equipmentsearch.asp 

Learn more about Dursban WG

Learn more about Wheat Bulb fly     

Refer to the Dursban WG Wheat Bulb fly Risk Assessment Chart

Always check the Cereals Pestwatch pages for the most recent bulletins.

Refer to the HGCA website for more detailed information on this year’s survey. 

 A number of agronomists and farmers have seen saddle gall midge damage in the last two years predominantly in wheat. Cases have been noted across the entire country mainly in central England but also in Scotland, often in or adjacent to continuous cereals, but not exclusively.

In order to help ADAS, AICC, Dow AgroSciences, HGCA and NIAB TAG understand the full extent of the problem and decide the best way forward, Dow AgroSciences is co-ordinating a survey on behalf of this group and your help would be much appreciated.

Complete the Saddle Gall Midge Survey.

Weather conditions have definitely taken a dip with air and soil temperatures falling. Periods of prolonged frosts are anticipated to continue especially for the north and west. Therefore conditions for the optimum efficacy with autumn applications of ALS chemistry are reducing.

This does not mean that all grassweed management is over now until next spring, as there maybe opportunities if the weather turns mild again – which it often does in a typical UK winter and the advice below would apply:

• Typically UK winters often have mild periods during which blackgrass growth continues putting on an increasing number of leaves and tillers by the spring
• These mild periods do present an opportunity to continue to use GF-2070 to control the blackgrass
• Despite the very cold winter last year a break in the cold weather occurred during the latter half of January:
  • Applications of pyroxsulam products during this period provided equivalent control to those in November
  • The use of a herbicide programme helps with managing the growth of the blackgrass during the winter reducing its size and providing some flexibility on spring timing

Therefore:

• During mild growing conditions in the winter where clear active growth is evident at the time of the application take the opportunity to control the blackgrass with GF-2070
• Where contact materials are not going to be applied during mild conditions, then ‘top up’ the residual chemistry to help manage the blackgrass and reduce its size come the spring

After a warm, dry autumn conditions in oilseed rape crops are suitable for maximising the activity from treatments with Kerb* Flo.

If field conditions allow, applications of Kerb Flo should be made, taking particular care to avoid contamination of watercourses.

• The activity of propyzamide, the active ingredient in Kerb Flo, is maximised under cooler soil conditions, i.e. at this time of year
• Propyzamide is a residual herbicide with root uptake that requires even distribution in the soil profile
• Treating large advanced crop canopies is a concern for many. Ideally where crops have a well-established canopy, wait until winter die-back has started, to allow applications to reach the soil surface. However, where this is not possible, product degradation of Kerb Flo is unlikely on the leaf as degradation is by microbial action in the soil. With sufficient rain, any Kerb Flo that has dried on the leaf will dissolve and drop-down onto the soil surface but coverage of the soil surface may not be ideal.  If faced with this situation when spraying Kerb Flo, use a minimum water volume of 200 L/ha, a medium to coarse spray and apply when the crop canopy is moist
• Applications should be made to firm, moist soils with a fine tilth
• Increased rates should be used where blackgrass resistance has been confirmed
• Use is recommended in tank mix or sequence with graminicides
• Take all precautions to avoid contamination of watercourses

There is currently no known strain of blackgrass, or any other grassweed, exhibiting any degree of resistance to propyzamide.

Learn more about Kerb Flo   

Check the latest weather data

I’ve used Spitfire for volunteer bean control. Can I come back with another application next spring?

On the Spitfire* label there is the following advice under ALS joint applications:

“Only one other product with an ALS inhibitor mode of action may be applied to a cereal crop treated with SPITFIRE. However a further application of SPITFIRE or another product containing florasulam may also be made providing the maximum total dose of florasulam is not exceeded.

The maximum total dose of florasulam applied to the crop must not exceed 7.5g/ha. For autumn planted crops a maximum total dose of 3.75g/ha of florasulam, must be observed for applications made between crop emergence in the year of planting and February 1st in the year of harvest.”

Practically, this means you can use up to 7.5 g/ai florasulam on a crop – this can be split into 2 treatments and still count as 1 ALS.  This means that where Spitfire has been used in the autumn, you can follow with another florasulam based product as long as you do not exceed a total of 7.5 g/ai. This is in addition to using another “non-florasulam” listed ALS such as Atlantis WG.

Similar wording is on all Dow AgroSciences “florasulam” based broad-leaved weed product labels.

Learn more about ALS joint applications

Which ALS herbicides can follow GF-2070?

This autumn many agronomists have already seen the superb control of blackgrass offered by GF-2070. They have also seen the added benefit of excellent control of many problem broad-leaved weeds such as cranesbill, groundsel, speedwells, poppy, volunteer OSR and beans to name a few. Depending on timing and residual partner the necessity of follow-up GF-2070 may not be needed. However, if necessary, GF-2070 may applied in joint application to the same cereal crop with one of the following ALS products:

Alias SX
Ally Express
Ally SX
Barton WG
Boxer
Galaxy
GF-184
Hiker
Hunter
Jubilee SX
Lorate
Slalom
Starane Gold
Starane Vantage
Starane XL

Again for the florasulam/fluroxypyr brands listed above the dose may be split.

Subscribing to Dow AgroSciences' Agronomy Update & Pestwatch gives eligibility for 1 Crop Protection BASIS Points annually. Please include course name "Agronomy Update & Pestwatch" and number "CP/19948/1112/g" on your training record. These details apply until 31st May 2012.

If you require any further information please contact our technical Hotline on 0800 689 8899 or your local Dow AgroSciences representative.

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

Always check individual product labels for any possible restrictions before making a tank mix recommendation. Please note where only Physical Compatibility or Sprayable with Continuous Agitation is shown, Dow AgroSciences has no biological data regarding efficacy or crop safety and only supports the compatibility, so growers use  these mixes at their own risk.

* Dursban, Equity, Kerb and Spitfire 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
GF-2070 contains flupyrsulfuron-methyl-sodium and pyroxsulam
Kerb Flo contains propyzamide
Spitfire contains florasulam and fluroxypyr

More info at www.dowagro.com/uk