More so than in winter wheat, control of problem weeds in winter barley, such as blackgrass and Italian ryegrass, has been reliant on a narrow group of actives.

So, the recently announced news that growers will have a new mode of action to add into pre-emergence mixtures this autumn is very welcome, particularly as the future of residual mainstay flufenacet is in jeopardy.

See also: Pre-em weed control in wheat – what to consider this season

Agronomists believe this should help maintain a sustainable level of control in the crop and preserve its place in rotations where weed management was becoming a make-or-break concern.

Barley strengths

Winter barley has plenty of advantages and some of those shone through this harvest, with the crop outyielding wheat in many situations across AICC agronomist Colin Woodward’s area in Oxfordshire, Warwickshire, Buckinghamshire and Berkshire.

It is also a year when oilseed rape has had a slight resurgence and growers have reported good yields.

And, in many cases, Colin says his clients’ best crops had been drilled early following winter barley.

With a relatively dry harvest, its other main strength was not really needed this year, but its ability to spread workload is particularly useful to farms stretching one combine over a large acreage.

“But trying to make some money out of it at current prices is a challenge, and we have the autumn weather to worry about. You must get it in early to get the yield.

“Weed control is the other main issue and that will only become more difficult if we lose flufenacet.

“We also don’t have much contact material for weeds like brome and wild oats,” notes Colin.

© Colin Wooward

In Dorset, CCC Agronomy adviser Brett Pointing sees winter barley as an important crop in the rotation, not least for its straw, which has been valuable this summer with forage in short supply.

Weed control concerns

He says sustainable weed control for the crop is a concern with flufenacet not only under threat, having been withdrawn within the EU already, but also suffering a slow erosion of efficacy.

With barley yields very dependent on early tiller survival, and its sensitivity to herbicides meaning it’s easy to knock and compromise that early development, herbicide programmes need careful consideration.

This has led to a reliance on flufenacet as the base of programmes, so Brett says it’s welcome that an alternative product containing two new actives to cereals in Britain has been approved.

Fundatis contains Isoflex active, the trade name for bixlozone, a HRAC (Herbicide Resistance Action Committee) Group 13 herbicide from the isoxazolidinone family, which inhibits carotenoid biosynthesis.

Its partner, beflubutamid, is from the same herbicide family as diflufenican (Group 12).

“Having that extra mode of action is certainly very welcome.

Brett Pointing © CCC Agronomy

“I think, initially, it will be used in mix with flufenacet, but moving forward I can see it becoming the base of winter barley programmes should it go,” says Brett.

Ryegrass activity

In his area, he has increasing issues with Italian ryegrass, which is likely being spread by equipment moving between fields, and he sees Fundatis as providing very useful activity on this currently difficult to control weed in winter barley.

Manufacturer FMC says control from an application of Fundatis averaged 66% in its development trials, and this level of efficacy has been reflected in independent work, too.

Combined with the recent approval of cinmethylin in winter wheat, which also has strong activity on Italian ryegrass, Fundatis will help get on top of the issue across the rotation.

© Blackthorn Arable

“A lot will come down to cost, but I can see it featuring highly in my programmes where grassweeds are an issue, knocking pendimethalin or prosulfocarb out of the mix,” he explains.

For Colin, although Italian ryegrass is an issue on some of the ex-dairy units he oversees, acetolactate synthase (ALS)-inhibitor resistant blackgrass remains the most challenging weed across much of his area.

Bromes and oats

Meadow and rye brome are emerging threats and sterile brome is appearing where growers are direct drilling.

Wild oats are another threat and Colin suspects there is resistance to sulfonylureas (SUs) in some brome and wild oat populations.

Manufacturer trials suggest 54% control of blackgrass is achieved by a single application of Fundatis, and although brome and oats aren’t on the product label, Colin says it has useful activity.

“The trials data I’ve seen are encouraging and we will be having a look this autumn and rolling it out gradually, once we’ve got used to the product and learned how to get the best out of it in barley.

“It’s active on blackgrass and I’ll be targeting it at the worst fields initially, partnered with flufenacet, pendimethalin and tri-allate,” he says.

Both advisers are also encouraged by what Fundatis can bring to the party on broad-leaved weeds, with a plethora of susceptible species on the label, including increasingly tricky weeds such as cranesbill and groundsel.

Brett says this is welcome to take some pressure off pendimethalin and diflufenican, which are relied upon to achieve good broad-leaved weed control.

Although most weeds are still sensitive in his area, an alternative mode of action for broad-leaved species in cereals is welcome for resistance management purposes.

“I’ve used less clomazone [a close relative of bixlozone] in oilseed rape over the past few years, so that group isn’t seen too much elsewhere in the rotation and should help.”

Autumn advice

Heading into this drilling campaign, Colin says one encouraging aspect is the good grassweed control achieved last autumn, which should have minimised seed return on many farms.

At the time of writing, plenty of cultivation plans had been executed and seed-beds were awaiting some rain to stimulate a flush of weeds for destruction with glyphosate ahead of drilling.

Colin is aware of the Fandatis product label’s instructions ahead of application, which are in line with best practice advice for any residual herbicide.

Fine and firm seed-beds are key to ensuring no crop effect and maximising weed control, and drilling depth is another important consideration: seed should be covered with at least 2.5cm of settled soil.

“We also need to do all we can to prevent drift, so a course nozzle [90% drift reduction type], low boom height and steady forward speed are all recommendations that will be written down on the spray plan,” he explains.

Manufacturer FMC has issued plenty of advice on getting the most out of the new product and a Basis training module will be going live in October.