What are you growing?

Agronomy Support

Agronomy Update – 21 October 2014

In this Edition

Getting the best ryegrass control in winter wheat
I have no blackgrass so why should  I bother with a “residual”?
What can I use to control volunteer beans in wheat?

This Edition’s FAQs:
Does Kerb Flo 500 control ryegrass?
Is there still “no –known” blackgrass resistance to Kerb Flo 500?
Can I use Galera this autumn?

Dates for the diary


Getting the best ryegrass control in winter wheat

Ryegrass in WWRyegrass is becoming more difficult to control. It’s a common grassweed in parts of the country such as Shropshire and Yorkshire but surprisingly enough can also be the key driver-weed in traditional “ blackgrass” areas such as Essex.

At the time of the last UK survey (*Moss, et al., 2011) resistance in Italian ryegrass was widespread. The most common mechanism is enhanced metabolism with target site resistance to ACCase chemistry also endemic. Resistance to ALS inhibitors has also been identified. Since this survey the number of farmers reporting difficult to control ryegrass has increased.

In blackgrass areas, farmers recognise the integration of cultural and chemical programmes is vital to keep the menace of grassweeds in wheat in-check. The big move now is to apply these essential tactics to ryegrass. Ryegrass produces more seed than blackgrass and is more competitive plant for plant than blackgrass. Less than one plant/m2  can reduce yield by 5%.  Autumn emerged ryegrass plants produce 23 times as much seed as spring emerged.

Perennial ryegrass seeds in the soil are viable up to 5 years; Italian ryegrass can be viable even longer.  The focus of control should be now as 94% of Italian ryegrass geminates in the autumn.

Key points for best control:

  • Use cultural control across the rotation
    • Rotational ploughing to bury seeds
    • Having a rotation
      -  Take advantage of using alternative chemistry such as Kerb® Flo 500 in oilseed rape.
      -  Shallow cultivate prior to rape for best effectiveness from Kerb Flo 500. This will give benefit to following wheat.
    • Stale seedbeds
  • Delayed drilling
  • Use of  effective pre-emergence e.g. Prosulfocarb 4.0-5.0 L/ha +/- Stomp Aqua 1.75 L/ha or Crystal 4.0 L/ha
  • Use Broadway® Star + adjuvant at the 1-3 leaf stage of the weed when actively growing.
    • Add prosulfocarb (if not used at pre-emergence), or PDM e.g. Stomp Aqua 1.75 L/ha, or Flufenacet based e.g. Crystal 4.0 L/ha , Liberator 0.6 L/ha or Vigon 1.0 L/ha. (Amend product choice/rate according to what was used pre-emergence)
  • Ensure optimum application.  Broadway Star Technical Infomation – Autumn 2014.

*Moss S R, Marshall R, Hull R and Alarcon-Reverte R, 2011.  Current status of herbicide-resistant weeds in the United Kingdom. Aspects of Applied Biology 106, Crop Protection in Southern Britain. 1-10.


I have no blackgrass so why should I bother with a “residual” in wheat?

The use of residuals either pre-emergence or post-emergence in winter wheat can give huge benefits. With much  post-emergence contact “chemistry”  under increasing resistance  pressure, the use of a residual is a vital way to achieve the very  highest level of control cost effectively. Many farmers know this already for blackgrass but it’s also making good sense where ryegrass and bromes predominate. It can buy time in that bromes and ryegrass are prevented from establishing and competing hard with the crop over winter . It will also mean any  grassweeds that do subsequently germinate  will be small  and easier to control with Broadway Star when  the weather conditions  are just right for best control. As well as helping improve control of the more competive and yield robbing, bromes and ryegrass, most residuals can also control annual meadow grass before it gets too big.

 


What can I use to control volunteer beans in wheat?

Spitfire  Vol bean control slide

With the demise of Pixie farmers are looking for reliable alternatives to control volunteer beans.

Volunteer beans have the capacity to compete with the crop but more importantly shade grassweeds from post-emergence “contact” grassweed treatments.  Spitfire® meets the needs of farmers for controlling this weed.

  • Proven autumn volunteer bean control at 0.75 L/ha + adjuvant
  • Approved for use in winter oats, winter wheat, winter barley and undersown cereals
  • Fastest speed of kill of currently available products. This means more subsequent opportunity for “optimal” timing of contact grassweed sprays.
  • Works in fluctuating temperatures
  • Extensive list of additional broad leaved weeds
  • Rainfast in 1 hour
  • Vol bean leavesSplit dose flexibility, can follow in Spring with florasulam + fluroxypyr formulations

 

Download latest Spitfire Technical Information sheet for advice on best use.

STOP PRESS
With the dry September, volunteer rape has survived pre-emergence herbicides.  Spitfire also offers excellent control of this aggresive weed.

 


This edition’s FAQ:

Does Kerb Flo 500 control ryegrass in oilseed rape?

Although not label weeds, Kerb Flo 500 and ASTROKerb® control perennial ryegrass and Italian ryegrass.  Application rates and treatment timings are the same as when targeting blackgrass.

Is there still “no –known” blackgrass resistance to Kerb Flo 500?

Kerb Flo 500 and its predecessors have a long history of providing farmers with a vital weapon in the armoury for controlling grassweeds. Over the years where we have independently tested “surviving”  blackgrass after Kerb treatment, it has proved susceptible and  no resistance to propyzamide has been found. Nearly always, further investigation points to  reasons such as  blackgrass germinating from depth, or in the past use when soils are too warm or dry as being responsible for poor control.

With increasing populations of blackgrass the use of programmes to give  control is increasingly vital. Independent trials established in autumn 2013 proved how effective a programme of Centurion Max followed by Kerb Flo 500 or ASTROKerb can be in controlling high levels of blackgrass in oilseed rape crops.

Applications of Centurion Max should be made in October followed, at least 14 days later, by Kerb® Flo 500 or ASTROKerb® in November.

Can I use Galera this autumn?

Galera®  (MAPP 11961) can be used this autumn. It may be sold by distribution until 31st January 2015.  All farm stocks need to be used by final approval date 30th September 2015.

Next year, Dow AgroSciences will be selling re-registered Galera (MAPP 16413) which can only be used from 1st March   and will have no autumn approval.

 


Dates for the diary

If you have questions or queries relating to any of our products or would like to speak to one of us face to face, come and visit us at your local event.

Nov 19th AgriScot, Ingliston
Nov 19th-20th Croptec, Peterborough

 


For more regular updates on agronomic issues, find us on Twitter and Facebook!

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

More information can be found at uk.dowagro.com

Use plant protection products safely.  Always read the label and product information before use.

Pay attention to the Risk Indication and follow the Safety Precautions on the label.

® Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow.

All other brand names are trademarks of other manufacturers for which proprietary rights may exist.

ASTROKerb contains aminopyralid and propyzamide
Broadway Star contains pyroxsulam and florasulam
Galera contains clopyralid and picloram
Kerb Flo 500 contains propyzamide
Spitfire contains florasulam and fluroxypyr


Dow AgroSciences Limited, Latchmore Court, Brand Street, Hitchin, Hertfordshire, SG5 1NH.Tel: +44 (0) 1462 457272.
Technical Hotline: 0800 689 8899 | UKHotline@dow.com | uk.dowagro.com

 

Read the full story

Grassweed Emergence Monitor

22.10.14 Cambridgeshire early drilledOverview

Plan Your Blackgrass/Grassweed Management

Effective weed control depends on understanding specific opportunities in each crop in the rotation. Combating grassweeds requires a mix of approaches, and cultural control techniques should always be used in combination with a robust herbicide programme.

A crucial step to achieving successful control of headache grassweeds in winter wheat is to monitor when grassweeds emerge, so that post-emergence treatments can be applied when weeds are small and actively growing. Over the last three years, Dow AgroSciences’ Grassweed Emergence Monitor (GEM), in conjunction with ADAS, has been a useful tool for showing how quickly blackgrass, sterile brome and ryegrass grow away in the autumn.

This autumn we are focusing on blackgrass in winter wheat. Sites are in two key blackgrass areas of the UK – Cambridgeshire and Oxfordshire, where they will be monitored every two weeks.

GEM includes:

  • Blackgrass sown 500 seeds/m2 and a “natural” unsown blackgrass population
  • Two planned drilling dates – late September and late October

It is important to remember that germination of grassweeds will also be subject to local factors and the information provided by GEM should supplement but not replace field monitoring.

If you would like to receive the latest GEM report directly to your inbox or would like to find out more about this service, please contact our Technical Hotline on 0800 689 8899, your local Dow AgroSciences representative or E-mail – ukhotline@dow.com.


Related Links

Print                                broadway-star      broadway-sunrise

Report 2 – 22nd October 2014

This week’s report:

It continues to be warm at both sites but rainfall has been higher than in previous weeks. Blackgrass is emerging rapidly, more so in Cambridgeshire than Oxfordshire. Blackgrass in Cambridgeshire is up to 2 leaves with that in Oxfordshire at half to one leaf. With continued warm conditions and rainfall rapid emergence will continue.

 22.10.14 early drilled Cambridgeshire

22.10.14 early drilled Oxfordshire

 All sown grassweeds are drilled at 500/m2. No herbicide treatment applied.

Current Advice for Grassweed Control in Winter Wheat:

This year blackgrass is predicted to have moderate dormancy, compared to the low dormancy seen in 2013. In practical terms germination from seed shed this season will neither be very rapid or very slow but now that moisture is not a limiting factor expect to see emergence. Monitor crops closely as optimum time for blackgrass treatment is 1-3 leaves.

The drier than average September, coupled with high blackgrass populations, means that stale seedbeds or pre-emergence herbicides in the early drilled may not have been overly effective. A robust and comprehensive herbicide programme is needed.

For those now being drilled a pre-emergence herbicide should be applied as soon as possible; this should then be followed post-emergence by a combination of residual and contact herbicides. Aim to complete the programme in the autumn on as small a target weed as possible.

Conditions are good for activity of UNITE® on blackgrass, which in common with all ALS-inhibitor graminicides works best when grassweeds are actively growing.

Where no pre-emergence has been applied due to dry soils, apply 240 ai g/ha flufenacet with UNITE + adjuvant.

Where a pre-emergence was applied but has not been totally effective due to dry soil conditions, add a ROBUST dose of residual partner + UNITE + adjuvant. Choose partner on basis of knowledge of the field / blackgrass population.

Don’t forget many broad-leaved weeds and other grassweeds will be controlled by UNITE which will alleviate many tank-mixing and sequencing issues. Mixes of UNITE + adjuvant + residual partner + BYDV insecticide are supported.

For further information on grassweed control in winter wheat see Topic Sheet 19 (Blackgrass) and Topic Sheet 20 (Brome & other grassweeds).

Use UNITE where blackgrass is the driver-weed.

Use Broadway®  Star where ryegrass, wild oats and bromes are the driver-weeds.

Read the full story

Aphid Report – Autumn Update 27th October 2014

The aphid monitoring programme conducted by Rothamsted Research has confirmed the presence of grain aphids (Sitobion avenae) and bird-cherry aphid (Rhopalosiphum padi) that carry the kdr mutation making them resistant to pyrethroid insecticides. Bird-cherry aphid and grain aphid are important as they transmit barley yellow dwarf virus (BYDV) in winter wheat and barley.

Pyrethroid insecticides, such as cypermethrin, have been invaluable in the control of aphid species as they have been cost-effective. However the over-reliance of pyrethroid insecticides has resulted in resistance.

Independent trials conducted in autumn 2012 and reported at Crop Protection Northern Britain 2014 (*Dewar et al., 2014) demonstrated that Dursban® WG was the most consistent insecticide treatment when applied against resistant or susceptible grain aphid. Dursban WG achieved faster aphid control than cypermethrin, vital when combating virus transmission.

aphid controlAction

Monitor crops and where aphid species are present and pyrethroid resistance is implicated, consider an application of Dursban WG or Equity®. Trial results have shown that applications of Dursban WG applied via LERAP 3* nozzles did not reduce aphid control.

If treatment is justified use Equity at 1.0 L/ha applied in 200 to 1000 litres of water/ha.

If using Dursban WG the recommended rate is 0/6 Kg/ha applied in 200 to 1000 litres of water/ha.

An interval of 14 days must be observed between applications of Dursban WG and UNITE® or Broadway® Star, regardless of weather conditions. For approved formulations of iodosulfuron-methyl-sodium and mesosulfuron-methyl leave a longer interval of 4 weeks for crop safety.

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

For conventional boom sprayer:

  • Use LERAP – low drift – three star nozzles
  • AND adopt a 20 metre no-spray buffer zone (1 metre for dry water bodies)

Say No to Drift

 

 

*A M Dewar, A J G Dewar, L A Haydock, S P Foster and M S Williamson. Alternative insecticides to control cereal aphids, Sitobion avenae, that are resistant to pyrethroids. Crop Protection in Northern Britain 2014, pp 136-136

Read the full story

Kerb Weather Data

Soil Moisture Deficit - Top 10 - 3rd October 20142nd Report – week ending 17th October 2014 

 

Welcome rain has caused moisture deficits to drop across the country and blackgrass to grow, however soil temperatures at 11°C – 14°C are still too warm for outstanding results to be achieved with Kerb® Flo 500  for blackgrass control.

Propyzamide, the active ingredient in KerbFlo 500, in common with other residual herbicides breaks down quickly in warm soils. If you treat now, it is likely the speed of breakdown will lead to insufficient concentration of propyzamide in the rooting zone of the blackgrass, inevitably leading to poorer levels of control.

For optimal blackgrass control Dow AgroSciences recommend Kerb Flo 500 applications are made when soil temperatures have got down to 10°C and falling, and there is sufficient soil moisture in the soil for plant uptake. Both these criteria are rarely met before November.

This advice has been proven in extensive trials over many variable autumns. Similar advice would apply to ASTROKerb®

More Kerb Weather Data will be supplied as the season progresses.

Check out application conditions for your local postcode

life cycle logo with strap line

Click on the My Farm LifeCycle to check out forecast conditions for optimizing Kerb Flo 500 and ASTROKerb applications on farm. Simply enter your postcode in the banner and click GO to view the results.

 

FAQs

If I wait, won’t the blackgrass roots be too big/too deep for outstanding control?

Propyzamide, the active ingredient for blackgrass in Kerb Flo 500 and ASTROKerb, works mainly by root uptake in the top 5 cms of soil. As long as the oilseed rape has been established using min-till techniques, the majority of the blackgrass will be shallow rooted and even when it develops a more extensive root system, is still likely to have sufficient roots in the Kerb activity zone for uptake.

With high populations of blackgrass the use of programmes to give control is increasingly vital. Adding a “fop or dim” with good blackgrass activity as a sequence e.g. Centurion Max, or where supported in tank-mix e.g. Laser, nearly always improves control and is frequently better than carbetamide/propyzamide programmes.

Independent trials established in autumn 2013 have proved how effective a programme of Centurion Max, followed by Kerb Flo 500 or ASTROKerb, can be in controlling high levels of blackgrass in oilseed rape crops. Applications of Centurion Max should be made in October followed by Kerb Flo 500, or ASTROKerb, in November (N.B. There should be a 14 day gap BEFORE or AFTER application of Centurion Max).

Download Topic Sheet 16 “Advice for Blackgrass Control in Oilseed Rape” for further advice.

 

Read the full story
lifecycle-large