In June, the Irish Farmers Journal visited a blackgrass trial site in the east of England.

It really was an eye opener - every plot had some level of blackgrass, no matter what the treatment applied was.

In some cases, four different herbicides were applied to the plots.

Avadex Factor played an important role in control. Levels were lower where it had been applied.

It should be noted this is a granular form of herbicide, where granules are applied to the soil. It is different to the product used in Ireland.

Other products such as Stomp and Defy were also used as a part of programmes, but many of the remainder of the products are not available in Ireland.

Some of the uncontrolled parts of the field had high levels of blackgrass.

One product was used in the trial that is expected to come to the Irish market in the coming years.

No control in a can

What the trial showed us was that there is no solution to blackgrass control in a can. Herbicides will control a certain level of the weed, but will not totally control the weed.

Blackgrass is resistant to most grass weed herbicides currently on the market. Those herbicides also add hugely to costs.

The cost of these programmes is also extremely high. Some farmers are spending £150 to £180/ha (€172 to €207/ha) on control, while others are even hitting £250/ha (€288/ha).

The main message is that you cannot control blackgrass using chemicals alone. If you do, the problem has the potential to get out of control.

Some of the better control in the blackgrass trial.

David Felce, whose farm we visited, had some of his land planted to a catch crop under the Sustainable Farming Incentive to get the weed under control and to help the soil to improve crop growth in the following crop.

A few things to remember on blackgrass:

  • One plant can produce 6,000 seeds, so the problem can get out of control very fast.
  • Delayed sowing will reduce numbers.
  • Spring planting significantly reduces levels of the weed.
  • Ploughing can reduce the weed by 70%.
  • However, these seeds should not be ploughed back up in the following years.
  • Higher seed rates can help to reduce it.
  • Break crops will give you some alternative herbicide options.
  • If you have high levels of blackgrass, you need to be prepared to whole-crop fields before the weed goes to seed or to spray off patches where the weed is.
  • You may even need to lay the field down to grass.
  • You should pull any blackgrass plants in a field where levels are relatively low or top or trim small patches in late May or early June, before they go to seed.
  • Leave fields with blackgrass until last when using machinery and clean down that machinery. This includes sowing equipment.
  • Machinery should be cleaned down when leaving fields.
  • Machinery coming on to a farm from another farm should be cleaned down.