Grab the chance for late season dock control in grassland

Broad-leaved weed flush on new grass leys 

Watch out for Frit fly!

KERB - protecting water quality

This edition's FAQs:

- What does Dow AgroSciences recommend pre-emergence of GF-2070 or Broadway Sunrise for blackgrass control?

- Where can I find ALS joint application lists for Dow AgroSciences' products? 

Ideal grass growing conditions with continuing warm weather offers farmers an unexpected opportunity to treat problem weeds such as docks this autumn. At this time of year, plants are drawing nutrients down into their roots in preparation for winter, rather than directing their efforts upwards to produce seed-heads. This allows the herbicide to work more effectively.

Herbicides such as Doxstar* work best when applied to docks that are growing uniformly across the field. Spraying a few weeks after cutting for silage or hay or after topping is ideal when weeds are still actively growing is ideal.

Apply Doxstar at 3.0 L/ha in 300 to 400 litres of water as an overall treatment in the autumn for the control of docks. If you have already applied the first part of the spring/autumn programme of 1.5 L/ha in the spring, remember to follow up with a second application of 1.5 L/ha this autumn.

On large well-established docks and where there is a large reservoir of seed in the soil a further control programme in the following year may be required.

Learn more about Doxstar 

Recent rains and showers have resulted in a flush of newly emerged broad-leaved weeds.

Product choice on new leys is increasingly restricted, but both Pastor* and Doxstar have recommendations. A new ley is considered to be grassland less than 12 months old. Both products are safe to grassland from the 3-leaf stage.
 
Doxstar has recommendations for control of common chickweed and seedling docks from the 2 leaf stage up to 50mm across at 1.5 L/ha in 200 litres of water.

Where a broader spectrum of weeds is present Pastor should be used at 2.0 L/ha in 200 litres of water from 2-leaf stage of broadleaved weed. Label weeds include:

Key: etl = established true leaves

Where there is a large reservoir of seedling docks in the soil, a further application in the following year may be required.

In addition to the above, although we do not have specific recommendations, there are a number of non-label weeds which Pastor has strong activity on. These include:

Key:  etl = established true leaves

A common situation is where large perennial weeds have survived the establishment of the ley and are competing with the crop. Control of these weeds is unlikely to be sufficient with the rates permitted on new leys and longer term measures in addition to the above, must be considered once the grass is established after 12 months. 

Both Doxstar and Pastor are rain fast within 2 hours if applied to a dry leaf.

Learn more about Doxstar

In late summer when grass swards are destroyed, there is a significant threat of Frit fly causing damage in the following grass ley or cereal crop. The main cause of this damage is due to the migration of Frit fly maggots out of the dying sward into the new sown grass ley or cereal crop.

Unless an interval of 6 weeks is left between ploughing up the old sward and sowing the new crop, the Frit fly maggots are likely to enjoy a new home in the vulnerable grass or cereal seedlings. This gives the classic poor establishment and “Dead Heart” symptoms associated with Frit fly.

The key to preventing Frit fly damage is to target the second generation larvae at migration. Many experienced agronomists get excellent Frit fly control by mixing Dursban* WG with glyphosate at sward destruction. Alternatively, if this is not possible having assessed the risk, application to winter wheat can be made pre-emergence (but post-drilling ), at emergence, or at the first sign of damage.  There is a label recommendation from emergence on new leys.

Later applications may be less effective.

Learn more about Frit fly

Learn more about Dursban WG 

The importance of ensuring oilseed rape herbicides are kept out of watercourses has not gone away. Guidelines are in place to help agronomists and farmers plan applications this autumn.

Kerb* Flo is a key component in the weed control strategy on arable farms where blackgrass, and other grassweeds, must be controlled in the rotation. However, steps must continue to be taken to minimise the instances of propyzamide being detected in watercourses.

Farmers and growers are advised to plant grass buffer strips wherever watercourses are adjacent to fields growing winter oilseed rape or winter beans. Evidence from field trials indicates that 6m grass buffer strips can reduce pesticide loss through surface run-off by over 50%. With national environment agencies and water companies detecting the main oilseed rape herbicides in water, extra steps including grass buffer strips are vital to protect water quality and the future use of these herbicides.

For maximum effect, grass buffer strips should be established at least a year before oilseed rape is sown. Many such strips were planted in 2010 and farmers and growers should look to establish buffer strips for both 2011 and 2012 plantings of winter oilseed rape and winter field bean crops.

The 6m grass buffer is recommended as the minimum on all soil types. However, in fields with slopes steeper than 5%, buffer strips may need to be increased up to 20m wide or more.

Dow AgroSciences have invested heavily in this important area of product stewardship with research in areas such as: the most effective crops to grow in buffer strips; the width of buffer strips needed; the most appropriate cultivation techniques in establishing buffer strips.

We must all play our part in protecting watercourses and ensuring the continued use and availability of these vital herbicides. If oilseed rape herbicides continue to be found in water then additional mandatory measures will eventually be enforced in drinking water catchments.

Review the Voluntary Initiative website for further information and guidance.

What does Dow AgroSciences recommend pre-emergence of GF-2070 or Broadway Sunrise for blackgrass control?

As winter wheat starts to be drilled, pre-emergence herbicide applications will be applied to provide a sound “stacking” foundation for optimal control. For either of these products in programmes, we recommend at least 240g ai /ha of a suitable product containing flufenacet applied within 7 days of drilling as the pre-emergence treatment.

If anticipating using Broadway* Sunrise* do be aware the formulation will provide 1099 g/ha of pendimethalin when used at recommended rates and the maximum permitted dose over the programme is 2000 g/ha of pendimethalin.

For blackgrass control applications of Broadway Sunrise or GF-2070 can be made in the autumn or spring up to 4 tillers of the Blackgrass. But as is the case with all ALS inhibitor chemistry optimum performance occurs from an application made in the autumn to a small actively growing target, typically at the 1-2 leaf stage of the blackgrass.

Where can I find ALS joint application lists for Dow AgroSciences’ products?

These can be found on our web site.

Learn more about ALS joint application updates

One practical useful point concerns “florasulam” based broad-leaved weed herbicides.

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 that as well as using in joint application with ALS products like Atlantis WG, you can split the Spitfire dose, use some in the autumn for volunteer beans and come back with the remaining dose of florasulam (up to 7.5g/ha total) in the form of a further application of Spitfire or another Dow AgroSciences broad-leaved weed (only) herbicide brand listed on the Spitfire ALS joint application list.

In effect the Dow AgroSciences “florasulam” based broad-leaved weed herbicide ( even if different brands)  applied as a split counts as one ALS, allowing you to still use another ALS on the joint application lists like Atlantis WG.

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

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.

* Broadway, Doxstar, Dursban, Kerb, Pastor, Spitfire and Sunrise are trademarks of Dow AgroSciences LLC.

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

Broadway Sunrise contains pyroxsulam and pendimethalin
Doxstar contains triclopyr and fluroxypyr
Dursban WG contains chlorpyrifos
GF-2070 contains flupyrsulfuron-methyl-sodium and pyroxsulam
Kerb Flo contains propyzamide
Pastor contains clopyralid, fluroxypyr and triclopyr
Spitfire contains florasulam and fluroxypyr

More info at www.dowagro.com/uk