Arable Update – February 2019

In this Edition

  • Two Pioneer hybrids make 2019/20 AHDB Oilseed Rape Recommended List
  • Belkar demonstration trials
  • Importance of controlling brassica weeds in cereals
  • Volunteer bean control in winter cereals
  • Don’t let cold conditions stop broadleaved weed control in cereals
  • Broadway Star timing and application advice
  • UK farmers give Arylex cereal herbicides a positive review

Two Pioneer hybrids make 2019/20 AHDB Oilseed Rape Recommended List

Two oilseed rape hybrids from Pioneer (part of Corteva Agriscience) have made the 2019/20 AHDB Winter Oilseed Rape Recommended List.

PT275 has consistently produced high yields coupled with a strong agronomic profile and good oil content to secure an East/West region listing.

With a UK listing, PT279CL is the only Clearfield variety to make the Recommended List and is the highest-yielding Clearfield variety ever to achieve either official registration in the UK or to be tested by the AHDB.

PT275 is the first double low hybrid from the Pioneer pipeline to reach the top level of the East/West table since PR46W21 which enjoyed enormous popularity among UK growers. With a published yield of 104% – the joint highest – the non-dwarf variety gets a 6 for light leaf spot and a 5 for stem canker.

PT279CL is another non-dwarf, double low variety and is the only Clearfield hybrid on this year’s list. It scores 6 for light leaf spot and 5 for stem canker with an oil content of 45%.

Belkar Demonstration Trials

Belkar demos

Ahead of its launch later this year, Corteva Agriscience is running a series of trials throughout the UK to demonstrate the activity of Belkar® oilseed rape herbicide.

Belkar is an autumn applied broad leaved weed herbicide used to control a wide spectrum of weeds in oilseed rape particularly cleavers, cranesbill, shepherds purse, poppies and fumitory.
If you have not received your invitation please register here and find out if there is a demonstration location and event near you.

Importance of controlling brassica weeds in cereals

The legal limit for erucic acid in finished oil crushed from oilseed rape grown by UK arable farmers may be reduced to a maximum of 2%, down from the current limit of 5% for oil destined for use in food products. This could cause serious issues for crushers, who are increasingly reporting incidences of elevated erucic acid levels in samples. For growers, this could mean rejected loads and subsequently additional costs.

Currently crushers will reject loads that are over 5%, but won’t necessarily make a claim for those reading between 2% and 5%, because the current testing technology allows a margin of error of 2% either way.

If the legal limit is reduced to a maximum of 2% however, this will undoubtedly lead to a much higher proportion of rejections.

Although the cause of the raised erucic acid levels is currently poorly understood, there are a number of projects underway with the AHDB, AIC and NFU to establish the source of the contamination. One commonly held view is that rapeseed volunteers and brassica weed seed in admixture may be the cause.

It is well known that brassica weeds are difficult to control in the oilseed rape crop. Unfortunately, it is these weeds that are potentially the source of the erucic acid contamination. Typically, charlock seed contains 32% erucic acid, runch around 27% and hedge mustard around 21%, so it’s easy to see how a poorly controlled infestation of these weeds could easily cause significant levels of contamination.

Rapeseed volunteers have also been implicated as another potential source of contamination.

Whilst it is difficult to control these weeds in the oilseed rape crop, controlling them is cereals is a much easier prospect. Herbicides containing florasulam, such Spitfire®, Broadway® Star and Zypar™ are particularly effective at controlling brassica weeds, especially if targeted early in the season when small.

Growers should monitor crops coming out of the winter and where brassica weeds are present, they should be targeted as soon as possible. Ideally, applications should be made when weeds are small and actively growing, but treatments can be delayed until later in the season provided conditions are favourable.

Don’t let cold conditions stop broad-leaved weed control in cereals

As the cold conditions persist this spring, delaying spray opportunities, growers will soon need to consider their weed control options, especially on late sown winter cereal crops that didn’t receive a residual herbicide pre-Christmas. Many of these fields will soon be full of spring weeds as the germination is triggered by the continuing frosts.

Unlike other herbicide options, Zypar (Florasulam plus Arylex) can be used early season, in cold conditions and still give high levels of weed control. Difficult weeds such as Cleavers, Cranes-bill, Brassica weeds, Poppy and Chickweed will be controlled by Zypar at 0.75l/ha. Zypar also has a broad range of compatibilities, allowing it to be safely mixed with a wide range of other products, including residual herbicides to broaden the weed spectrum.

Volunteer bean control in winter cereals

winter bean volunteers in wheat

In many winter cereal crops after beans, volunteers are present. The combination of high levels of seed return from the 2018 crop and mild conditions, has meant even volunteer spring beans are present in significant numbers.

Volunteer beans can be competitive weeds, especially in high densities and can shade grass weeds, which in turn can reduce the performance of contact acting grass weed herbicides such as Broadway Star.

Spitfire (florasulam and fluroxypyr) and Zypar (florasulam and Arylex™) offer outstanding control of volunteer beans. Zypar at 0.5L ha can control large volunteers (up to 8 true leaves), while Spitfire plus adjuvant at 0.5 L/ha will control beans at 4 true leaf and 0.75 L/ha + adjuvant for beans at the 6-true leaf stage.

Zypar and Spitfire are both compatible with an extensive range of other tank mix partners including insecticides and residual herbicides.

Broadway Star timing and application advice

Broadway Star offers excellent control of bromes (up to weed GS 24), ryegrass (up to weed GS 29), wild oats (up to weed GS29), as well as a wide range of broad-leaved weeds including cranesbill, cleavers and brassica weeds.

Critical to achieving high levels of weed control is application to actively growing weeds. Based on research over many years, our advice is to apply when soil temperatures (at 10cm) are greater than 6°C and a 7 day mean air temperature >8°C.

Figure 1. below compares air temperatures, in Derbyshire, between 2017 and 2018. The graphic shows that in 2017 suitable air temperatures for Broadway Star occurred from the 19 March, whereas in 2018, suitable air temperatures for application began from 16 April.

As well as timing, using an approved adjuvant, following general best practice spray guidelines (nozzles, water volume, boom height etc.) and sprayer loading procedure (pouring the granules at a controlled flow into the induction hopper) are also key to getting the best results with this product.

Broadway Star Temperature

Figure 1. Air temperature (°C) in 2017 and 2018 for Derbyshire


UK farmers give Arylex cereal herbicides a positive review

A survey of 141 UK farmers, carried out by independent market research company Kynetec, investigating Arylex based cereal herbicides Pixxaro EC (fluroxypyr + Arylex™) and Zypar (florasulam + Arylex™) was conducted in 2018. The main reasons for use above other herbicides (in order of priority) were efficacy on weeds, crop safety, wide spectrum of weeds and reliable control even in low or variable temperatures. Other attributes such as control of difficult weeds such as fumitory and following crop flexibility were also cited as reasosn for use. Figure 2. is an example of the feedback on Zypar.

Figure 2. Farmer responses to question. “In order to summarize your user experience, how would you describe Zypar to another farmer / advisor?” (n=57)


The Corteva Agriscience™ Arable Update gives you eligibility for 2 CP BASIS points

Subscribing to Corteva Agriscience™ Arable Update gives eligibility for 2 Crop Protection BASIS point annually. Please include course name “Arable Update” and number “CP/59315/1718/g” on your training record. These details apply until 31 May 2019.


If you require any further information please contact our Technical Hotline on 0800 689 8899 or your local Corteva Agriscience 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.

®™ Trademarks of DuPont, Dow AgroSciences and Pioneer and affiliated companies or their respective owner.  All other brand names are trademarks of other manufacturers for which proprietary rights may exist. 

Belkar contains Arylex and picloram
Broadway Star contains pyroxsulam and florasulam
Pixxaro EC contains Arylex and fluroxypyr
Spitfire contains fluroxypyr and florasulam
Zypar contains Arylex and florasulam

Corteva Agriscience, Agriculture Division of DowDuPont, CPC2, Capital Park, Fulbourn, Cambridge, CB21 5XE.  Tel: +44 (0) 1462 457272.