• Summer Clean Up of Grazing Pastures
• Powdery Mildew in Sugar Beet
• Pre-Harvest Grain Store Tidy

• This Edition’s FAQs:

  • Can Pastor be tank mixed with MCPA or 2,4-D?
  • What do I need to be aware of if using Dow Shield 400 on maize crops intended for anaerobic digesters?
  • Do I have to withhold grain for 90 days after using Reldan 22 for fabric treatment?

Now is the perfect time to control those unsightly grassland weeds. Pastor* is the best solution in grazing pastures that have succumbed to mixed weed populations including docks, nettles and thistles. If the weed spectrum is less broad, more tailored products can be used for optimal weed control namely Thistlex* for thistle control and Doxstar* for dock control.

Using Pastor within the following guidelines will help ensure long-term control:

• Apply when weeds are actively growing at the rosette stage
• If weeds have reached stem extension, consider cutting and making applications to re-growth
• Use at 4.0 L/ha (or at a rate suitable for target weed – see table) on established grassland (maximum rate of 2.0 L/ha on new sown leys)
• After application, allow 28 days before cutting to allow optimal translocation to the roots
• Stock should be excluded for 7 days or when the foliage of poisonous weeds has died and become unpalatable.
• If weed populations are dense and there are large seed reserves in the soil, a second application the following year may be advantageous.
• For further information on successful grassland management, click Critical Success Factors.
   

  

Choice of sugar beet variety is usually determined by yield potential but growers should be vigilant that the top yielding varieties may be at risk from high disease pressure. On the BBRO/NIAB recommended list of varieties for 2012, the top 5 yielding varieties all have a disease resistance rating of 3 or less for powdery mildew. So in order to maximise those yields, ensure protection against powdery mildew forms part of your management strategy.

Erysiphe betae (powdery mildew) infection in sugar beet is usually seen from mid July and can easily be identified by white/grey fungal mycelia and spore growth on the leaf surfaces. Over a period of time this fungal growth will turn the leaves yellow and cause them to die back resulting in a reduction in green leaf area, sugar content and yield.

Applications of Fortress* at 0.3 L/ha in 200 L/ha water should be made when the first signs of disease are seen. Quinoxyfen, the active ingredient of Fortress, is taken in by the plant and distributed throughout thereby protecting new and existing growth from infection for up to 8 weeks. If more than 5% of the crop has powdery mildew before applications are made, Fortress should be applied in tank mix with a fungicide that has curative activity.

A two spray strategy may be more beneficial where high and sustained levels of powdery mildew are expected or where crops are likely to be lifted later and re-infestation is expected. Fortress can be applied as a split treatment of two 0.2 L/ha applications. If a second application is planned, the latest timing is 28 days before harvest.

For more information on Fortress, including tank mix information, Click Here.

Picture courtesy of Central Science Laboratory

Big investments are made to maximise yields in the field so don’t risk yield losses post-harvest with poor grain store hygiene. Mite and insect infestation in UK stored grain causes annual losses of 5-10% and populations can build rapidly so it is important to take preventative action. Mite and insect feeding results in direct yield losses but can also have a detrimental effect on the quality of stored grain. Grain store pests can affect the nutritional value and act as a source of allergens which can lead to serious gastric problems in feeding animals. Whether intended for milling, malting or feed, infested grain runs the risk of being rejected.

Good ventilation, drying and cooling are important processes in grain store management but pests, in particular mites, can still breed at low temperatures of 5°C. Respiring insects and mites will generate heat and moisture and can cause localised hot spots within the grain pile which further promote breeding and may encourage the development of moulds.

Reldan* 22 is a broad spectrum acaricide and insecticide that will control all major pests of stored grain including Acarus, Lepidoglyphus and Tyrophagus, the three main mite species found in UK grain stores. Reldan 22 is the only pre-harvest grain store treatment effective on these common pests. Once treatments are dry it is safe to tip grain but fabric applications of Reldan 22 should be applied 4 weeks prior to grain filling to allow sufficient time for pests harboured in cracks and crevices to emerge and come into contact with the chemical. Reldan works by fumigation, contact and ingestion and offers protection for up to 6 months against mite and insect infestation. There is no withholding period for grain subsequently stored on those premises. 

Action Plan:
Grain store fabric treatment using Reldan 22 should be used as part of an integrated management approach:

1. Ensure grain store is emptied of any old grain and debris
   • Apply the same principles to grain handling equipment
2. Sweep (or use a high pressure airline) grain store paying close attention to crevices
   • Ensure sweepings are disposed of well away from grain store sites or ideally, burn them
   • Wear appropriate PPE including a dust mask
3. Apply Reldan 22 at 200ml in 5 Litres of water per 100 m² up to 4 weeks before harvest via a knapsack, motorised knapsack or tractor-operated spray lance.
   • For best practice ensure good ventilation during application and wear a face mask fitted with an activated charcoal filter.

Reldan 22 can be used as a fabric treatment for stores intended for wheat, barley, oats, rye and triticale (not oilseed rape) and can also be applied directly for grain as an admixture to these qualifying cereals.  For more detailed support literature on Reldan 22, please visit our website.

Can Pastor be tank mixed with MCPA or 2,4-D?

This approach is not recommended as the quick ‘burn down’ of the top growth with phenoxy herbicides will hinder the movement of Pastor to the roots of perennial weeds, thereby leading to poor levels of control. The same is true for Doxstar, Forefront*, Forefront T, Thistlex and Grazon* 90.

What do I need to be aware of if using Dow Shield 400 on maize crops intended for anaerobic digesters?

If using Dow Shield^# 400 on maize crops intended for anaerobic digesters please be aware there is a risk of clopyralid residues in the digestate. If spread onto land intended for cropping with clopyralid sensitive crops such as field beans and potatoes there is a risk of crop damage. Warning details for following crops are given on the label. Click here for more information on Dow Shield 400.

For recently approved recommendations for forage maize click here.

Do I have to withhold grain for 90 days after using Reldan 22 for fabric treatment?

No. The 90 days withholding period only applies to grain that is treated directly with Reldan 22. There is no withholding period for grain when Reldan is applied pre-harvest as a fabric application to stores. 

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.

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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.

* Doxstar, Forefront, Fortress, Grazon, Pastor, Reldan and Thistlex are trademarks of Dow AgroSciences LLC.
^# Dow Shield is a trademark of the Dow Chemical Company.
All other brand names are trademarks of other manufacturers for which proprietary rights may exist.

Doxstar contains triclopyr and fluroxypyr
Dow Shield 400 contains clopyralid
Forefront contains aminopyralid and fluroxypyr
Forefront T contains aminopyralid and triclopyr
Fortress contain quinoxyfen
Grazon 90 contains clopyralid and triclopyr
Pastor contains triclopyr, fluroxypyr and clopyralid
Reldan 22 contains chlorpyrifos-methyl
Thistlex contains clopyralid and triclopyr


More info at www.dowagro.com/uk