Winter Oats

The recent rain has helped oat crop to green up with many crop developing the typical dark green colour over the last few days. Most crops are up to date with PGR and the second fungicide application. Disease levels are relatively low as a result of the recent dry weather with the exception of some crown rust in the south.

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Tillage Grassweeds

The knowledge of the potential threat  grass weeds pose to an individual farmer and indeed the tillage industry is increasing.  Grass weed identification, appropriate control measures, and prevention of seed return is critical to ensure the seedbank is depleted year on year.   There are a number of good videos on identification of grass weeds here with specific videos on Blackgrass, bromes, wild oats and canary grass also available.  

Integrated Weed Management (IWM)

An integrated weed management (IWM) approach needs to be taken if grass weeds are identified on your farm. Combining cultural control measures like rotational cropping, alternating between winter and spring cropping and using stale seedbeds or cover crops in addition to chemical control using herbicides with alternate modes of action will enable the best control and prevent herbicide resistance from developing.

Prevent Seed Return

Prevention of seed return to the soil is key to controlling grass weeds. Early pre or post emergence herbicide application, destroying grass weeds early, or stem extension stage within the crop using specific grassweed herbicides (Broadway Star, Pacifica, Axial etc.) or graminicides ( Falcon, Stratos Ultra, etc) where necessary.  Once grass weeds become too large, herbicide control will not be reliable and either hand rogueing or total destruction of the crop is essential. 

Field Assessment

Careful, early field assessment and identification of the weed is required in May/June before the seed ripens. Only then can a decision on total crop (and weed) destruction be considered. Although extreme, this option is the best course of action where populations of blackgrass, Italian ryegrass, bromes or canary grass are too numerous to be hand rougued.  

Blackgrass should be rogued or destroyed once the seed heads are visible.  Seeds can be viable once the flowering anthers begin to disappear and the head begins to darken in colour.  Patch spraying rather than total field destruction may be appropriate but consult your advisor to help with the field assessment.

Herbicide Resistance

The ECT grass weed project has tested a large number of field populations for resistance and weeds such as blackgrass and italian rye grass are showing some significant resistant issues.   

Black-grass and Italian ryegrass Survey May 2022

Do you think you have Blackgrass or resistant Italian Ryegrass in your fields?

The Teagasc ECT Project research team are trying to determine the extent of herbicide resistance in Ireland and the specific nature of that resistance which would indicate the best IWM control strategies to use. But we need your suspect samples of grass weeds to achieve this.

For research and advice, this would allow us to map this resistance evolution in Ireland and develop national control strategies. For the grower, it gives valuable specific knowledge about herbicide resistance on their farm which will help determine control methods.

To participate in the survey and free resistance sampling service, please click on the link below. All information provided is strictly confidential. For any further information please email John Mahon (ECT Project Advisor) at john.mahon@teagasc.ie or Vijaya Bhaskar (ECT Project Researcher) at vjaya.bhaskar@teagasc.ie.

Survey link : https://www.surveymonkey.com/r/LYC7FNP

Broad Leaf Weed Herbicide Resistance Study

Teagasc are also conducting an initial study in 2022 looking at broad leaf weed herbicide resistance. If you suspect you have a resistance case of Chickweed, Corn Marigold, Poppy or Speedwell please email john.mahon@teagasc.ie for further information.