08 August 2024
Get your weeds tested for herbicide resistance
Teagasc is offering a herbicide resistance testing service for tillage farmers. With a break in the harvest, Ciaran Collins says that this is the last opportunity to inspect crops for uncontrolled weeds and to collect samples for herbicide resistance testing if resistance is suspected.
Do you have uncontrolled weeds in your crops this year? If so, can you identify a logical reason for their presence? Uncontrolled weeds might result from choosing the wrong herbicide, applying it at an insufficient rate, or encountering issues during application. However, if you cannot easily explain the presence of these weeds, it might indicate a herbicide resistance issue in the field.
All grassweeds should be treated with caution particularly blackgrass, brome species and Italian rye grass and herbicide resistance testing is advised where these weeds are present. The level of annual meadow grass in winter crops seems to be higher than normal this year. Whether this is a symptom of the wet weather in 2023/2024 or an indication of a greater issue is difficult to determine at this stage, but it is strongly advised to test any uncontrolled annual meadow grass that was treated with a herbicide that claims control.
Herbicide resistance is not confined to grass weeds, chickweed is increasing in abundance every year in addition to poppy, corn marigold and speedwells. Where these weeds (or others) are poorly controlled, herbicide resistance testing can provide you with essential information on how to put a control plan in place.
Testing will be carried out as a part of the Department of Agriculture, Food and the Marine funded EVOLVE research project. This information is invaluable if you have a resistance problem, but is also immensely important to the research project in mapping resistance evolution.
Information on how to collect samples is provided in the QR code below or on the Herbicide Resistance Testing Application Form (PDF).
Also read: The benefits of cover cropping