Think black-grass isn’t that big a deal? Think again

Black-grass is a serious grass weed which has the ability to devastate the cereal industry in Ireland if it is not controlled.

Just 1 plant/m²/ha can result in the return of six million seeds. It is also an extremely competitive plant. 12 plants/m²/ha can result in a 5% decrease in yield.

Ireland’s wet weather also favours growth conditions for the plant. There is no chemical option that will fully control black-grass on the market.

Cannot be ignored

If you have a black-grass problem don’t ignore it. At this stage of the season black-grass should have been brought under control, and the parts of fields where infestation had occurred mapped and cleared of weeds.

If you have a field affected by the crop it should not be planted with a winter cereal. Spring planting results in a dramatic decrease of plant populations of the weed.

Weak spots

However, black-grass does have some weak spots. 80% of the seeds will emerge in the autumn – meaning that a stale seedbed can play a significant role in curbing the weed.

Black-grass seeds cannot germinate below 5cm, so the plough can also help to control the weed.

Also Read: The ‘Brian Cody approach’ to grass weed control

Send your samples

If you have a grass weed problem then you can contribute to Teagasc’s Enable Conservation Tillage (ECT) project by collecting ripe seeds from your fields. Try and get as substantial a sample as possible. Hopefully, with weeds like black-grass, there will be limited seeds available.

You can then send the sample in a sealed envelope to Jimmy Staples – the advisor on the ECT project at Teagasc. It is important not to spread seeds, so ensure that the seeds cannot get away.

Seed samples will be used to identify the grass weed types which are present in Irish tillage fields. The level of resistance to chemistry can also be examined.

Seeds can be sent to: Jimmy Staples, Teagasc Crops Research Centre, Oak Park, Co. Carlow.