Take note of grass weeds from the combine

When combines return to the fields it might be a good idea to take note of grass weeds you see on your travels and take samples where possible. These samples can be sent to Teagasc to check for herbicide resistance.

If you note these weeds and their locations you must then take action and decide on a plan to control them. This might be the use of a stale seed, a break crop or the inclusion of an appropriate herbicide next season.

Preventing the spread

Preventing the spread of these weeds is essential. If you are using a contractor you should ensure that the combine has been cleaned down before arriving on your farm to prevent the spread of weeds from one farm to another.

If you are using your own combine ensure that you clean the combine if you have a grass weed problem in one field and not in another.

Machinery is one of the many ways that grass weed seeds can spread. Farmers purchasing machinery from the UK should ensure it is clean before importing it.

Straw and seed from other countries is also a source of seeds. In the UK, there is a tolerance for black grass in certified seed, so there is no guarantee that UK seed is free from black grass.

Grass weed survey

Teagasc is currently gathering information on grass weeds and herbicide resistance as part of the Enable Conservation Tillage (ECT) project.

The questionnaire aims to assess growers’ awareness of herbicide-resistant weeds, as well as their perception and adoption of resistance management strategies.

The information gathered from the survey should help to increase researchers’ and advisers’ understanding of grower concerns and it will also be used to help to improve knowledge transfer activities and to help to develop a weed containment programme which is practical to implement.

If you would like to take part in the survey you can do so by clicking here.

Full control of black grass cannot be obtained from a herbicide. Approximately 5% of fields sampled here in Ireland showed herbicide resistant plants within their wild oat populations.

These plants were resistant to pinoxaden, propaquizafop and cycloxydim (Axial, Falcon and Stratos Ultra). Information on these weeds and agronomy management is essential.