Black-grass: solutions to the problem

Resource explained

A good combination of methods for weed management can help you control black-grass, reduce your herbicide costs, and keep you in line with environmental regulation. This information sheet published by AHDB summarises key methods for increasing your control of black-grass, indicating levels of control that can be achieved which are based on a comprehensive review of more than 50 field experiments. It outlines important non-chemical methods (e.g. ploughing, delayed autumn drilling, spring cropping etc.) and their effectiveness in controlling black-grass. It also provides essential information for understanding black-grass and its behaviour (e.g. emergence pattern and depth, etc.). It presents an example of how a combination of chemical and non-chemical methods can help you achieve as much as 99% control of black-grass.

Findings & recommendations

• About 80% of black-grass emerges during autumn, when most UK farms sow their crops.
• Drilling your field will not get rid of black-grass – it emerges with crops.
• Herbicides alone may not be able to control black-grass on your farm:
  • Resistance to herbicides is increasing
  • Herbicides are not the cheaper option on some fields
  • Existing herbicides may be withdrawn due to regulation
• Priority should be given to non-chemical methods of plant protection wherever possible:
  • Rotating
  • Ploughing
  • Delayed autumn drilling
  • Competitive crops
  • Spring cropping
  • Fallowing/grass ley breaks
  • Methods for preventing seed return and spread of resistant seeds
• Different control methods have different efficacies, so tailor them to your field.
• Five key factors are essential to the success of an integrated control strategy: Emergence pattern, emergence depth, seed longevity in soil, population dynamics, and competitiveness.
• Do resistance tests: they will tell you if your herbicides work on your weed, save you from unnecessary herbicide use, and help you plan long-term strategies. However, lack of ‘resistance’ to non-chemical methods means that they should provide more durable control than chemicals.