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Agronomy Support

Arable Update – September 2017

In this Edition

  • Prioritise winter wheat fields for autumn treatment of sterile brome with Broadway Star
  • New option for broad-leaved weed control in the autumn: Zypar
  • Spitfire for volunteer beans
  • Kerb Weather Data Tool Update
  • Blackgrass control with either Kerb Flo 500 or AstroKerb

Prioritise winter wheat fields for autumn treatment of sterile brome with Broadway Star

Let’s face it, spraying ALS herbicides such as Broadway™ Star in the autumn is not easy: short days, wet soils, lack of a dry leaf and varying temperatures all add up to the opportunity of perhaps spraying one or two loads in the middle of the day! That said trials work by Dow AgroSciences and independent organisations such as NIAB and Rothamsted Research continues to show that for sterile brome and ryegrass control, best results (weed control and crop yield) are achieved by spraying in the autumn. Digging into the data there are three principle reasons why this is the case:

  • Weed size – Broadway Star, like many herbicides, is more efficacious when applied to small weeds and in the case of Sterile Brome, beyond 4 tillers control is compromised and the result is more likely to be a stunted plant.
  • Active growth – ALS herbicides do require active growth of the weeds, in the autumn, the soil acts, to a degree, as a heat source, radiating the summer warmth (!) and this warmth can give reliable active growth despite variable air temperatures. In the early spring the reverse is true and the cold soil can hold back growth even though air temperatures may be suitable.
  • Ability to add TM partners such as pendimethalin giving you another mode of action and providing residual control of late germinators and reducing the risk of resistance developing.

The most practical approach is to prioritise your highest risk fields for autumn treatment with Broadway Star. The table below gives some help in factors to consider when prioritising fields.

With Broadway Star it is important to use the product as part of a programme with other residual herbicides such as pendimethalin and flufenacet, our technical information sheet (see our Broadway Star Autumn Tech Sheet) has details on these programmes based on an extensive programme of trials over many years.

Residual Partners
There is often confusion about which are the best residual partners for Broadway Star. Again based on ours and others experiences, our suggestions are as follows:


  1. Base the programme around pendimethalin as the first preference – minimum of 2,000g ai/ha pendimethalin in the programme
  2. Apply a pre em of 1,200g ai/ha pendimethalin +/- flufenacet e.g. Crystal 4.0 L/ha
  3. At 2-3 leaf of the brome ideally in the autumn apply Broadway Star + adjuvant+800g ai/ha pendimethalin


  1. Base the programme around prosulfocarb as the first preference
  2. Apply a pre em of prosulfocarb
  3. At 2-3 leaf of the ryegrass ideally in the autumn apply Broadway Star + adjuvant + flufenacet and/or pendimethalin

The final point is make sure that attention to detail is paid when actually spraying Broadway Star. In the following short video, Stuart Jackson from Dow AgroSciences explains the important points to consider.  Optimising Broadway Star Applications.

New option for broad-leaved weed control in the autumn: Zypar

 Following the successful launch of Zypar™ in spring 2017, this will be the first autumn that Zypar is available for use in winter cereals. Zypar brings contact activity to a wide range of autumn germinating broad-leaved weeds including poppy, chickweed, cranesbill, groundsel, brassica weeds e.g. volunteer OSR, volunteer beans and cleavers. It can be added to residual herbicides that are targeting grassweeds such a pendimethalin and flufenacet. Over a number of years we have found that an autumn/early spring application of Zypar plus a picolinafen based product such as Picona controls meadow grass and broad-leaved weeds in a single pass!

Reasons to use Zypar in the autumn:

  1. No weather worries – the unique combination gives outstanding control in low and variable temperatures
  2. Control of a broad spectrum of weeds including weeds such as cleavers, cranesbill and volunteer beans that can come through early applications of residual herbicides
  3. Tank mix compatibility with a wide range of residual herbicides, insecticides and trace elements
  4. No following crop restrictions and reducible buffer zone (LERAP B)

The maximum rate of Zypar that can be applied before the 14th of February is 0.75 L/ha. It should be applied to a dry leaf and is rain fast within 1 hour.

For more information see: Zypar.

Spitfire for Volunteer Beans

Spitfire™ remains as the tried and tested product for the control of volunteer beans in the autumn. The combination of active ingredients is important: the fluroxypyr delivers rapid disruption to growth of the beans while the florasulam element ensures an effective kill, even in cold conditions.  Compared to other options for volunteer bean control, Spitfire offers simplicity:

  • No DFF in the product (keeps things simple for following crops)
  • A reducible buffer zone (LERAP B).
  • Fully supported tank mixes with residual herbicides, insecticides and trace elements.
  • Not as restrictive on following ALS sequences such as Thor
  • Wide weed spectrum including groundsel, cleavers, mayweeds and volunteer oilseed rape

Based on our trials work, recommendations for volunteer bean control are:

  • 0.5 L/ha + adjuvant – Beans at 4 true leaf (2 pairs)
  • 0.75 L/ha + adjuvant – Beans at 6 true leaf (3 pairs)

For more information see our Volunteer Control topic sheet

Kerb Weather Data Tool Update

New for 2017, Dow AgroSciences have updated and refreshed the Kerb Weather Data (KWD) tool on its website (available from mid-October).

With great new icons, the refreshed tool not only gives a great indication by postcode of soil temperatures and moisture but also rainfall and wind predictions to help growers and advisors plan their spraying workload.

This tool is meant to be used as a guide to local weather conditions to aid growers and advisors make tactical decisions to optimize their ASTROKerb™ and Kerb™ Flo activity against blackgrass.

If you use AstroKerb or Kerb Flo 500 when the traffic light is on red, soil temperatures may be too high, propyzamide will breakdown quickly and blackgrass control may be compromised.

In forward crops, large canopies may be closing in rows before the KWD tool indicates green for go. Dow AgroSciences trials over a number of years have shown blackgrass control from propyzamide is not impeded by large crop canopies.

Always adhere to stewardship guidelines especially with respect to water, help ensure we keep essential active ingredients in our armoury to help grow our crops.


Blackgrass control with either Kerb Flo 500 or AstroKerb

To optimize the blackgrass control activity from your ASTROKerb or Kerb Flo 500 application, ensure that propyzamide, the active ingredient in both these products, is in contact with the blackgrass roots for as long as possible. Soil temperature plays an important role to achieve this.

Cooler soil temperatures slows propyzamide breakdown and ensures blackgrass roots can take up propyzamide for a longer period of time, thus optimizing weed control. The graph below shows how soil temperature can affect propyzamide half-life.


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.
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 propyzamide and aminopyralid
Kerb Flo 500 contains propyzamide
Broadway Star contains pyroxsulam and florasulam
Spitfire contains fluroxypyr and florasulam
Zypar contains halauxifen-methyl (Arylex active) and florasulam

More information can be found at

Dow AgroSciences Limited, CPC2, Capital Park, Fulboun, Cambridge, CB21 5XE.  Tel: +44 (0) 1462 457272.
Technical Hotline: 0800 689 8899 | |


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Grassland Agronomy Update – May 2017

Welcome to the Grassland Agronomy Update from Dow AgroSciences.

These regular technical notes are a seasonal commentary to help those interested in improving grassland productivity on dairy, beef, sheep & equestrian enterprises.

You can claim two CPD points for subscribing to this email update.


  • Target docks after silage
  • Leystar on maize
  • Spray thistles in May/June
  • Dose rates and perennial weeds
  • Spot treat with GrazonPro
  • Right time to spray buttercups
  • Use the Grassland APP for 24/7 support
  • FAQs
  • Dow AgroSciences show calendar

Target docks after silage

docks regrowing after cutting
You need 3 weeks before cutting to spray Doxstar®Pro to enable it to fully translocate down into the dock roots. Where that window is not available plan to spray around two weeks after cutting instead.

The re-growth will have fresh green leaves and all at a similar stage, ideal for taking up a translocated herbicide. There will be less grass too making it easier to hit the target plants.

DoxstarPro gives good control of both broadleaved and curled docks. Apply at full dose rate of 2 L/ha in a water volume of 300 L/ha, unless air inclusion nozzles are being used, when the water volume can be reduced to 200 L/ha.

DoxstarPro is very safe to grass – recent market research carried out by Dow AgroSciences shows this is still top of the concerns for grassland farmers who spray herbicides.

Leystar on maize

New Leystar® has approval for post-emergence weed control in maize

Leystar combines clopyralid, fluroxypyr and new active for maize florasulam making it a very wide broad spectrum herbicide.

It should be applied when the forage maize is between the three and six leaf stage and before the crop is over 20 cm tall. It must not be applied once the buttress roots have started to develop on the first node.

Annual weeds that will be controlled include:

  • Black nightshade
  • Black bindweed
  • Charlock
  • Chickweed
  • Cleavers
  • Fat hen
  • Mayweed

LeystarLeystar will be an ideal partner in a program where pendimethalin is used.

The dose rate is 1.0 L/ha and it can be applied to maize from 10th April to 31st May. We hope to have this cutoff date extended for 2018 use.

Find more information on our Leystar Technical Information sheet.


Spray thistles in May/June

May/June is the time to spray thistles. Thistles tolerate dry conditions and will outcompete grass for any residual moisture. They prevent animals grazing all the grass in a field and are thought to help spread orf, a highly contagious viral disease of lambs and ewes.

The virus lives in the surface of the skin, but infection gets going once the skin is scratched by lambs grazing too close to thistles.

Affected ewes often develop mastitis. Infected lambs do not grow as quickly as healthy lambs, and they take longer to finish and market.

Topping thistles gives only temporary reprieve, especially with creeping thistles as they produce more stems from buds running below ground after cutting.

Options for spraying thistles

  • Where thistles dominate, spray with Thistlex® using a tractor mounted or self-propelled sprayer. Thistlex also controls nettles.
  • If the area taken by the thistles is less than 5%, spot treat with Grazon®Pro.
  • If a broader range of weeds is involved, use the Pas·Tor® Agronomy Pack.

All these products will take out all species of thistles, such as Spear, Creeping or Marsh. Tackling them now reduces the amount of new plants that will germinate from seed this year.

Dose rates and perennial weeds

Dose rates on products are set using the criteria minimum effective dose. Reducing a dose rate particularly on perennial weeds is likely to result in poor weed control and survival.

Adjuvants can have complimentary activity e.g. drift retardence or limiting the effect of herbicide lock up in hard water areas but adjuvants are not a substitute for dose when targeting perennial weeds.

When adjuvants are used on crops destined for human or animal consumption, residues data must be submitted, showing the effects of the adjuvant on pesticide residue levels.

No residues data will be required where the adjuvant is used with a pesticide half or less than half the approved rate of the pesticide.  Reducing the rate by this level and including an adjuvant is also false economy. The effect on the target weeds will be significantly reduced from spraying at the full rate on its own. Further lower rates leads to more incidences of repeat spraying which is not good for the environment and with many grassland sprays being applied by a contractor, unnecessary cost.

Spot treat with GrazonPro

There is really only one option for spot spraying in grassland and that’s Grazon®Pro. There is a need to be able to control small areas of docks, thistles, nettles and other weeds by hand, for example around gateways and water troughs. It is also more cost effective than a boom spray where weed populations are below 5%.

  • GrazonPro contains 60 g/litre of clopyralid + 240 g/litre of triclopyr
  • Excellent control of broadleaved dock, curled dock, creeping thistle, spear thistle and common nettle and a large range of other weeds
  • Fast acting and translocates down to the roots
  • Animals can be re-introduced after only seven days (not if ragwort is present)
  • Rainfast in two hours
  • Very safe to grass
  • Good value for money – 16 knapsacks from each litre of product when mixed in 10 litre batches
  • Comes with free measuring beaker

GrazonPro is for professional use and can only be used by suitably qualified people who hold a PA1 and PA6 certificate.

Right time to spray buttercups

Best levels of control are achieved before flowering. If you spray when they are in flower you can still get good control but not to the same level as if sprayed earlier.

Envy® – our new solution for weeds typically found in pastures which receive minimal nitrogen, controls both creeping and meadow buttercups, daisies and dandelions and is also pretty effective on plantains.

These weeds will smother grass and limit the provision of forage to grazing animals. Envy contains florasulam + fluroxypyr, it has no manure management restrictions after use – so ideal to use in pony paddocks. Its short stock withdrawal period of just 7 days makes planning in its use much easier then phenoxy based options which require a 14 day stock withdrawal period.

Use the Dow AgroSciences Grassland APP for 24/7 support

Use the Dow AgroSciences Grassland APP for 24/7 support and to access product labels, product technical sheets and our FAQ database at any time.

Download the Grassland App, by using one of these links:

App Store / Google Play / Windows Store 

If the App is already downloaded, please ensure the latest version is being used.


Q.  How does the Pas·Tor Agronomy pack compare to PastorPro?
One Pas·Tor® Agronomy Pack will treat 2 hectares and give the same level of control that Pastor®Pro would do if it was applied at 3.0 L/ha.

Q.  Can I use Envy through a knapsack?
No. Its use in this way is not supported by Dow AgroSciences. The only product we have for knapsack use in established grassland is GrazonPro which should cover all needs.

Q. I want to make the Forefront®T stewardship recommendation via the APP but I don’t have a smart phone, what do I do?
Use the stewardship feature on the web:


Show Dates

The technical team from Dow AgroSciences will be out and about at many shows and events this summer, talking to farmers and agronomists and answering questions on how to tackle weed problems in their fields.

Catch the team at:

May 24th &  25th Grassland & Muck Stoneleigh Park, Warwickshire
May 31st NSA Highland Sheep Strathpeffer, Ross-shire
June 7th NSA North Sheep Tow Law, County Durham
June 8th Scottish Beef Event Earlston, Berwickshire
June 20th NSA Sheep South West Tiverton, Devon


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

For further information please contact the technical Hotline on 0800 689 8899 / or go to

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.

® 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.

DoxstarPro contains fluroxypyr and triclopyr
Envy contains fluroxypyr and florasulam
Forefront T contains aminopyralid and triclopyr
GrazonPro contains clopyralid and triclopyr
Leystar contains fluroxypyr, clopyralid and florasulam
PastorPro contains clopyralid, fluroxypyr and triclopyr
Pas·Tor Agronomy Pack contains clopyralid, fluroxypyr and triclopyr
Thistlex contains clopyralid and triclopyr


Dow AgroSciences Limited, CPC2, Capital Park, Fulbourn, Cambridge, CB21 5XE.  Tel: +44 (0) 1462 457272.
Technical Hotline: 0800 689 8899 email: |



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View All Topic Sheets
What is the current situation with regard to Unite?

Unite, along with other products that contain flupyrsulfuron, are now subject to a withdrawal notice. The timelines are as follows:

Up until the 13 December 2017 Unite can be sold (sales period)

Up until the 13 December 2018 Unite can be used, stored or disposed of (use-up period)

Full details of the withdrawal notice can be found here

Please note this withdrawal does not affect Broadway Star and Palio

Why is Unite subject to a withdrawal notice?

The active substance, flupyrsulfuron, has not been approved for renewal at an EU level. Note this does not affect Palio and Broadway Star as these products do not contain flupyrsulfuron.

What are the following crop restrictions/cultivation requirements for Pixxaro EC?

After an application of Pixxaro EC at 0.5 L/ha up to BBCH 45, the following crops may be sown.
• Autumn: Beans*, Cereals, Clover*, Grass, Lucerne*, Oilseed Rape, Peas, Phacelia
• Spring: Beans, Cereals, Clover, Grass, Lucerne, Maize, Oilseed rape, Onions, Peas, Potatoes, Sugar beet, Sunflowers

*Plough prior to sowing

The Pixxaro EC label advises ploughing prior to sowing winter beans, however, Dow AgroSciences support autumn sown field beans without ploughing prior to drilling, following an application of Pixxaro EC (in spring to the previous cereal crop) with one exception: high pH soil (8 or over) in a dry summer, in these situations ploughing is then recommended prior to drilling autumn sown field beans.
We are working on adding following crops such as carrots, brassica transplants and borage as a following crop.

Which pre-emergence herbicide should I use for ryegrass control in a Broadway Star programme?

Use 3200 g  ai / Ha of prosulfocarb.  Additional pendimethalin may help.

Can the straw from oilseed rape treated with ASTROKerb be used for animal bedding?

Oilseed rape straw from crops treated with ASTROKerb needs to remain in the field and must not be baled and used for bedding.  It may be removed from the field to be used for burning for heat or elctricity production.

Can I plant cover crops even where they are not listed as a following crop on the label?

The planting of any crop (not subject to human consumption/MRL requirements) not specifically  recommended on the label would need to be at the users risk where following crop safety has not been demonstrated.

What is the knapsack rate for DoxstarPro, Forefront T, Pas·Tor and Thistlex?

These products are not recommended for application through a knapsack. GrazonPro at 60 ml in 10 litres of water is the best product for spot treatment.

Will any Dow AgroSciences product control ragwort in horse paddocks?

No Dow AgroSciences product is recommended for control of ragwort in horse paddocks. The best method of control is to dig them up. 2,4-D can be used as an overall spray.

What products do Dow AgroSciences recommend to control brambles in grassland?

Brambles should be sprayed between June and August, when plants are actively growing, but before plants begin to senesce in the autumn.

It is essential that all foliage is thoroughly wetted or incomplete kill may result. The maximum concentration must not exceed 60ml of GrazonPro per 10 litres of water.  

Blaster Pro can be used to control brambles in amenity grass.