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 | |