How a farmer’s 10-year battle is banishing blackgrass

A decade of dedication to ridding his farm of blackgrass has paid off for Cambridgeshire grower Edd Banks, who intends to continue with his long-term plan.

Having originally set his sights on eliminating the grassweed from the 1,200ha farm back in 2007, he is now down to a few troublesome fields – a far cry from the almost overwhelming situation that prompted him to take drastic action.

Those odd fields are a reminder of what might happen if mistakes or leniency creep in, with Mr Banks being determined to maintain his attention to detail, banish blackgrass and achieve a total victory.

See also: How to stop blackgrass adapting to a spring cropping strategy

“The farm is clean, but not spotless,” he says. “And we’re aiming for spotless.”

Herbicide spend

Even with today’s manageable blackgrass population and limited seed return, he is still spending £100-140/ha on pre and peri-emergence herbicides in winter wheat (see panel), as well as hand roguing some problem areas.

“As weed numbers have reduced, our control measures have become more targeted,” he says. “But it would be foolish to think that we had finished – what were our best fields 10 years ago are now the worst.”

Progress is down to a combination of factors – with cultural and chemical control methods being used alongside rotational and management flexibility, all backed up with a “can-do” attitude from the farm team and agronomist.

Blackgrass in winter wheat

© Tim Scrivener

Fine-tuning

“We change something every year,” notes Mr Banks. “The last three years have been all about fine-tuning the system, so that our results are consistent and the farm’s profitability doesn’t suffer.”

Ploughing has stopped so that soils are undisturbed in the spring. Any cultivations needed ahead of sugar beet or spring cereals take place in the autumn, with only the top 3-4cm being worked to limit any weed germination from depth.

Having 90ha of sugar beet in the rotation has made things easier, he acknowledges. “We don’t get blackgrass in our beet, thanks to its spring drilling date and different chemistry.”

Other spring crops include 40ha of spring barley, which fits behind late-lifted sugar beet, and 40ha of spring oats grown on a gluten-free contract. Both have proved to be a very competitive break crops – also helping with blackgrass.

Establishment success

After a revival in its fortunes, winter oilseed rape is now the main break crop at Thomas Banks and Partners. It is established behind hybrid winter barley, so that it can be drilled quickly and cost-effectively at the end of July.

“By abandoning our subsoiler drill we’ve halved our establishment costs and increased our yields from 2.1t/ha to 3.6t/ha. The crop is up and way ahead of the flea beetle and while there’s moisture.

“It also outcompetes any early germinating blackgrass, with a well-timed propyzamide-based spray taking care of the rest.”

Actives

  • Avadex – tri-allate
  • Broadway Star – florasulam + pyroxsulam
  • Crystal – flufenacet + pendimethalin
  • Liberator – (diflufenican + flufenacet)
  • Monolith – mesosulfuron + propoxycarbazone

Application technique

In winter wheat, a great deal of energy and concentration goes into ensuring that pre-emergence herbicides are applied for maximum effect and in optimum conditions.

Water volumes of 200 litres/ha are used, boom height is kept to 0.5m above the crop, the latest nozzles are employed and forward speeds are kept below 12kph.

“I’m told that you can get a 30% improvement in herbicide performance by using 200 litres/ha of water rather than 100 litres. That’s worth having.”

Sam Harvey of Bayer points out that delaying drilling until mid-October is another way of getting more from the pre-emergence programme.

“There’s a 30% boost in Liberator’s performance at this later timing, as it goes on when conditions are more favourable for it and there’s sufficient soil moisture.”

Herbicide programme at Manor Farm, Harlton

Edd Bank’s usual routine is to apply a Crystal/diflufenican mix and an Avadex application as soon as possible after drilling, with glyphosate.

This is then followed by a 0.6 litres/ha top-up of Liberator at the peri-emergence stage.

That sequence has done a tremendous job this year, he reports, so he is now reviewing if any further action is necessary.

Although spring-applied contact herbicides haven’t been used for years, the arrival of Monolith from Bayer may change that, as it offers improved blackgrass control and brings in bromes and wild oats.

“We have had to spray Broadway Star in the spring to deal with these other grassweeds, so this is an interesting alternative at an equivalent cost,” he comments.