• Spraying Backward Rape Crops with Kerb Flo 500
• Weed Control in Wheat after Potatoes/Sugar Beet
• This edition's FAQ:
  • How good are UNITE and Broadway Star at controlling Volunteer Beans? 

 

Some judgement on risk may be
necessary for crops which have yet
to reach the three leaf stage.

Many crops are yet to grow much beyond the two to four leaf stage.

Crop selectivity for propyzamide is by depth protection of the roots.  Applications to very small oilseed rape plants can cause problems such as stunted growth with leaves fused to the axil, or stem/yield depression. Once a crop has reached the three true leaf stage the roots are at sufficient depth to not take up a dose of propyzamide that could cause problems.

The “best” blackgrass approach, proven by extensive trials, is to apply Kerb* Flo 500 at the correct timing - usually November/December   This means there is still time to spray providing it doesn’t get any wetter, preventing travel completely.

Kerb Flo 500 applications may be made to 31st January.

For additional control, Kerb Flo 500 can be tank mixed with a ‘fop/dim’.  In high populations of “difficult” blackgrass, superior control can be achieved by adding a ‘fop/dim’ to Kerb Flo 500 (even when ‘fop/dim’ resistance is present) over a carbetamide/propyzamide treatment.

Thinking ahead to later this year, Kerb Flo 500 may be applied in frosty conditions but do avoid application onto frozen ground where subsequent rainfall could result in run-off into water–courses.

Due to slugs, pigeons and slow growth so far, some are thinking ahead as to spring cropping options just in case the rape does not pull through. Options after a November application of Kerb Flo 500 include March drilled beans and peas, and April drilled spring oilseed rape at farmers’ own risk.

‘Rake ‘n’ Roll’ – An integrated approach to blackgrass management

The benefits of achieving a stale seed bed prior to the establishment of cereals and oilseed rape are well-known, but not always easy to achieve when a fast turnaround between harvest and drilling, as with oilseed rape establishment, is required.

To highlight the importance of an integrated approach to grassweed management, Dow AgroSciences are supporting the trial of a new cultural technique, the ‘Rake ‘n’ Roll’ cultivator. The trailed implement manufactured by Tillso consists of spring tines which scratch the stubble surface, distributing straw trash and allowing any shed grassweed seed to some into contact with the soil. Tines go no deeper than 5mm so soil to seed contact is achieved without burying the seed. This is crucial as blackgrass seed needs UV light to germinate, and if seed is buried it is more likely to lie dormant. A studded rubber roller follows the tines, pushing the seed into the soil and promoting conditions favourable for germination. The emerged flush of weeds can then be sprayed off prior to drilling with a non-selective herbicide. This approach is ideal in situations where resistance is known or suspected and will optimise the performance of post-emergence herbicides.

Ian Corr, Dow AgroSciences’ Regional Business Manager based in Yorkshire visited the ‘Rake ‘n’ Roll’ site last week.

Ian said “What we have now is a flush of blackgrass uniformly germinating from the same depth, ideal to control with Kerb Flo 500, which will be sprayed when soil temperatures are less than 10^oC and conditions allow travel. We hope to see the positive impact of this blackgrass control in the next crop and in the rotation.

Now the sugar beet and potatoes are finally getting lifted, some wheat is being drilled. These crops will be going into the winter later drilled than normal with plenty of moisture to encourage weed  germination. Optimal weed control will be vital this season in order to maximise yield potential and financial returns from late drilled, backward crops. Seeking value from investment in crop protection products will be a priority.

Dow AgroSciences’ blackgrass products have a big part to play in meeting these needs.

The “optimum” blackgrass programme is still an option – a pre-emergence application of  flufenacet containing product, followed by an autumn application of UNITE*

• Minimum 240g ai/ha flufenacet (additional residual can be added)
  • Applied as a pre-emergence ideally within 24 hrs of drilling
• Apply UNITE + residual (e.g. 800g ai/ha PDM) + adjuvant
  • In the autumn at 1-3 leaf of the blackgrass
  • During actively growing conditions
  • Using FF or VPFF 110° nozzles  or Defy nozzles
  • Fine-Medium spray quality
  • Water volume 100-150 L/ha (optimum 130 L/ha)
• UNITE + adjuvant + residual partner is compatible with the following BYDV insecticides:
  • Cypemethrin EC, Decis Protech, Fury 10EW, Hallmark Zeon, Karate 2.5 WG, Mavrik, Sumi Alpha

Where it is not possible to do the optimal sequence an alternative to consider is tank mixing the "pre-emergence" with UNITE and applying it as a post-emergence treatment.  In previous, more clement autumns we have found these mixes to be physically and biologically compatible but would counsel caution if crops are under stress.

This is our best advice for this scenario:

• At 1 leaf of the crop apply a tank mix of UNITE + 240 g/ha flufenacet** based product + adjuvant.
  ** A dose rate of 240g ai/ha flufenacet is compatible with UNITE - BUT WATCH OUT FOR STRESSED CROPS. 

As well as excellent control of blackgrass, UNITE will control many other grass and broad-leaved weeds. Although not on the label it will control volunteer sugar beet to 4 true leaves.

This autumn has been challenging and optimal weed control will be vital in order to maximise yield potential and financial returns from late drilled, backwards crops. Download our current topic sheet for more information. 
 

Q. How good are UNITE and Broadway Star at controlling Volunteer Beans?

A. Although not on the label, both these products offer excellent control of volunteer beans - up to 6 true leaves for UNITE and up to flower-buds visible for Broadway* Star.  Spitfire* is an alternative for volunteer beans in situations where grassweeds are not a priority.  Details of Spitfire recommendations were given in the October Agronomy Update.  All of these products offer excellent control of volunteer oilseed rape and mayweeds, which are being highlighted as problem weeds this autumn.

Subscribing to Dow AgroSciences' Agronomy Update & Pestwatch gives eligibility for 1 Crop Protection BASIS Points annually. Please include course name "Agronomy Update & Pestwatch" and the number "CP/24531/1213/g" on your training record. These details apply until 31st May 2013.

For more regular updates on agronomic issues, find us on Twitter!    Follow @DOWAGROUK 

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

Dow AgroSciences supports the safety and efficacy of its products for tank mixes shown as Physically and Biologically Compatible, but does not warrant the efficacy of other tank mix partners.

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.

* Broadway, Kerb, Spitfire and UNITE are trademarks of Dow AgroSciences LLC.
All other brand names are trademarks of other manufacturers for which proprietary rights may exist.

Broadway Star contains pyroxsulam and florasulam
Kerb Flo 500 contains propyzamide
Spitfire contains fluroxypyr and florasulam
UNITE contains pyroxsulam and flupyrsulfuron-methyl-sodium

More information can be found at www.dowagro.com/uk