Top tips for using the crop for black-grass control

1. Target drilling of winter wheat after the main flush of black-grass, which is typically from early September to the middle of October, depending on soil moisture.

This will mean there will be more opportunity to control black-grass before the crop is drilled, and reduce the pressure on chemistry used in the growing crop. It will also help maximise the performance of residual herbicides as there is more likely to be moisture available to activate the herbicide and help it work more effectively.

2. A vigorous crop is one of the best tools for weed control; don’t sacrifice vigour for the sake of other parts of the programme like drilling too late or using too big a pre-emergence stack.

A competitive crop can be as effective as a herbicide component of a control programme. Drilling in good conditions to get fast, vigorous establishment of the cereal crop is important to help achieve a competitive crop. In less than ideal conditions, or at later drilling dates, increasing seed rates will help maintain crop competition. In good conditions, where drilling depth is consistent, a herbicide stack will help maximise black-grass control. In poorer conditions, where drilling depth can be inconsistent because of cloddy seedbeds for example, care needs to be taken with applying too many residual herbicides in a stack because of the risk to crop establishment. A gappy crop allows black-grass to potentially flourish.

3. Be ready to switch from a late drilled cereal crop to a spring crop if conditions turn against you.

It is better to wait to establish a spring crop than to try and force a late-drilled winter crop in, and having poor establishment, low crop competition and poorer control of black-grass. A spring crop should give a better chance of drilling in good conditions, while also maximising the chance to remove black-grass pre-drilling.

4. The main benefit of a cover crop is to improve soil conditions and spring crop establishment – don’t get too hung up on the potential direct effects on black-grass.

The main impact of a cover crop is that it helps establish a spring crop, which gives the best opportunity to spray off autumn-germinating black-grass. Cover crops are a very useful tool to help establish spring crops on heavier soils because they can help improve soil structure, reduce soil moisture and increase soil nutrition.

5. Delaying drilling reduces the levels of black-grass which germinate with crops & also improves control from Liberator  as there is a greater likelihood of soil moisture going into October

Getting the most out of residual herbicides, especially from pre-emergence applications, is the foundation of the herbicide control programme. An AHDB project has shown that delaying drilling by three weeks from mid/late September into October not only reduces the amount of black-grass that emerges, but also improves the performance of pre-emergence herbicides, such as Liberator, by 26%.