Maximise Sward Productivity by Controlling Grassland Weeds this Spring.

26th April 2022

Jonathan Crawford, Fane Valley Agronomist assessing weed control options for grassland on farm in County Down.

The control of annual and perennial weeds is critical to efficient grassland management enhancing performance by maximising grass yield and ensuring optimum sward utilisation.

After what has been a relatively mild winter, weed growth has been vigorous this spring.  Docks and chickweed are nutrient hungry weeds and will compete with the sward for nutrients and moisture.  Early control of docks can help maximise yield and feed quality of silage. Fields with a 10% dock infestation can reduce silage yield by 10% and with a feed value of only 60-65% of grass they can reduce fermentation in the pit and reduce dry matter intakes.

Docks in most swards are now at the optimum size and stage of growth to treat with herbicide.  Ideally, they should have sufficient leaf surface area (size of a dinner plate) to take up herbicide and are at the correct stage of growth allowing the chemical to move from the leaves down to the roots and effectively kill the weed.  Where weeds are larger and flowering, it is best to delay herbicide applications and then treat the new regrowth after cutting or grazing.

In reseeds, weed control is most effective when weeds are at the 2-6 leaf stage.  Seedling docks, chickweed and redshank are often present and effective long-term control is often best achieved when treated at this stage.

Fane Valley stock a wide range of grassland herbicides and bio-stimulants which can be co-applied with herbicides to reduce possible checking of grass while also providing a timely boost to growth rates.  Your Fane Valley Agronomist can help you to assess the weeds present in your fields and develop a specific plan of action tailoring management on a field-by-field basis as necessary.

To maximise the productivity of your grassland this season, please contact your local Agronomy and Forage Specialist or the office on 028 9261 0485.