Get weed seed samples tested for resistance now

Ciaran Collins, Teagasc Tillage Specialist, reports on a unique free testing service to check for herbicide resistance in grass or broad-leaved weeds in your fields.

The period between now and harvest is the perfect time to walk through your crops and assess how well weeds were controlled this year. If weeds are present can you explain the reason why?

There may be a number of reasons why weeds were not controlled such as delayed herbicide application, poor herbicide choice, inappropriate herbicide rate or poor weather at herbicide application timing. If one of these scenarios explains why weeds are present in a crop then this is a valuable lesson for next season. However, if there is no obvious reason for the presence of weeds then you may have a weed resistance issue on your farm.

The results of herbicide resistance testing from 2022 samples paint a worrying picture, where >70% of blackgrass or Italian ryegrass tested were resistant to both ACCase and ALS herbicides. We also found poppies resistant to ALS and/or hormone type (2,4-D) herbicides.

If you suspect that you may have herbicide resistance in grass or broad-leaved weeds (specifically, blackgrass, Italian ryegrass or poppy) in your fields, use this unique free testing service to check it. This will allow you to identify an effective herbicide programme to be used in conjunction with integrated weed management strategies. Good sample collection is essential for successful testing. Contact your advisor, or follow the instructions on: https://bit.ly/3MrlcgR or take a picture of this QR code using your smart phone:

A useful technique to gather seeds is to cover the top of the plant with ‘party bags’ (pictured above). This will allow the seeds to fall into the bag and not onto the soil and makes the collection of seeds much easier.

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