The grass weeds section was the highlight of last week’s National Tillage Conference for most. It’s a strange highlight to have given the seriousness of the problem, but maybe that’s because people want information and want to spread the word on how to keep out and control these weeds.

VJ Bhaskar gave the state of play. Blackgrass, Italian ryegrass, brome and spring wild oats are all showing resistance to herbicides – Italian ryegrass and brome have shown some resistance to glyphosate. The problem is getting more serious.

John Cussans from ADAS, who we featured on the tillage pages two weeks ago, told the audience that if they have a grass weed problem, resistance testing has to be one of the first things you do. Test the seeds and see what herbicides they are resistant too and crucially what herbicides work on controlling the weeds.

The real message that hit home from the conference was from English farm manager Adrian Joynt. He first encountered blackgrass in 2013. A field which had been in carrots came back into his rotation.

There were patches dotted across the field in different densities in one field and in other fields it was dense in one patch and more widespread at lower densities. He was able to trace back the source of some of the blackgrass.

He had taken in broiler manure and this was one source. The broiler unit had been feeding wheat. He noted that milled wheat is a much lower risk as weed seeds should be milled. Amazingly he traced another infestation to a plot combine which had harvested trials.

The blackgrass was in the trial area. A contractor’s baler had also brought some in as he could see the blackgrass where the baler first travelled.

First loss could be the least expensive

Adrian made a important point which is if you see blackgrass you need to act immediately. He explained that spraying off a large patch of blackgrass in a field might sound dramatic and expensive, you will lose grain, but it is the most inexpensive thing that you can do in the fight against blackgrass because if you stop the problem early it should be easier to control.

Adrian has a zero-tolerance approach to blackgrass. He sprays off the worst affected areas, hand rogues fields and puts affected fields into spring barley for a minimum of two years followed by stubble turnips. Spring planting reduces the population by about 70%.

When harvesting he harvests affected fields last and whether a field is affected or not he cleans down the combine leaving each field. This is done in the gateway so if the seeds germinate he will see them and know there is a problem.

If fields have blackgrass then the straw is chopped to keep the problem contained. In other fields, contractors still bale, but machinery is cleaned before arrival to reduce the risk of bringing in another issue.

Adrian is a big fan of stale seedbeds and if he is using farmyard manure he tries to leave it 12 months so that seeds break down.

He commented that he stopped using broiler manure as, while it was cheap to use, it ended up being costly when it brought in blackgrass.

Adrian also warned that in some break crops the herbicide may not control the blackgrass and by the time it is harvested the blackgrass has grown, but it couldn’t be seen under the canopy of oilseed rape for example.

Learned from the mistakes of others

Adrian is based near Shropshire and he said he was lucky that he learned from the mistakes of farmers in the east of England who had a bad blackgrass problem before the rest of the country and continue to have that problem. Knowing the seriousness of the issue he was able to act quicker. It should be noted much of the straw imported into Ireland is reported to be coming from the east of England.

Yet, having learned from those farmers and reacting quickly to the problem he still has huge costs. He acknowledged that it is not unusual for a farmer to be spending £140-150/ha on blackgrass control.

All readers know grain farmers cannot afford to lose £10/t. An additional cost which he found it hard to put a cost on was hand rogueing.

Many farmers in England pay teams of people to rogue fields but Adrian’s team also do this job and it is taking huge time from their working days.

Adrian’s blackgrass tips

  • Keep it out – it can come from the most unlikely source.
  • Zero tolerance – the first loss is usually the smallest loss.
  • Don’t rely on chemical control alone.
  • Chemical control is the last option not the first option.
  • Learn from the experience of others.
  • Good drainage – blackgrass likes wet ground.
  • Don’t be complacent.

    • Quotable quotesBox

    Here are some of the quotes that stood out at this year’s tillage conference.

    “If you asked me to put a number of years on it, I would say several, probably five to ten.” – Ewen Mullins of Teagasc on how far the EU lags behind the USA on new genomic techniques.

    “Yield is a huge component of both the farm income and the carbon footprint of the grain.” – John Mahon, Teagasc.

    “Once we can prove beyond reasonable doubt that Irish grain is very carbon efficient or carbon neutral, we need to work with users of Irish grain to make sure the market returns some value for that.” – John Spink, Teagasc.

    “Stop drilling if you can’t spray the crop you just drilled.” – John Cussans of ADAS in the UK on the importance of using pre-emergence herbicides to control grassweeds in cereal crops.

    “I wouldn’t say you can ever get rid of blackgrass, but you can make it much more manageable.” - Adrian Joynt, arable farmer in England.

    “Bringing in straw from Spain is quite dangerous.” – John Cussans, ADAS.

    “No uncommon in the east of England to spend £140/ha over £100/ha is a I minimum spend - £10/t.” – Adrian Joynt on the cost of blackgrass control in England.