Did you know 1 capful of MCPA leaked into the a water outlet, will POISON a water source for 30 Kilometers ?

Good weed control in grassland is just as important as it is in an arable field, whether it is a young sward trying to compete with broadleaved weeds or, in an older established sward where docks or rushes have crept in. Weeds reduce productivity, forage quality and in some cases can harm livestock. As all business strive towards a more efficient future, effective weed control has never been more important.

Why are rushes such an issue?

Rush seeds will survive in the soil for at least 80 years, meaning that no matter which option you use, there will be a requirement for follow up treatments and a change of practice. A healthy grass sward will always out compete juvenile rushes, so in order to eliminate rushes from a field, action needs to be taken to improve the outlook for the grass in the field.

Basically, a change of mind set is required, you’re not trying to kill the rushes, you’re trying to grow more grass. To do that, firstly you have to treat the rushes, commonly by spraying, weed wiping, cutting or flailing, thereafter, you need to rectify the real reason the rushes are there. Is it a drainage issue, a pH issue, or a nutrient issue such as Phosphate or Potash? You need to ascertain what is holding back your grass, once you know this, controlling rushes should be a much easier task.

What are the herbicide options and what do you need to consider?
Where rushes are present and becoming increasing prevalent, it suggests there are wider issues at play with rushes favouring poorly drained, hungry soils, where grass growth is sub-optimal. Herbicides can be used to control them, but only as part of a broader approach to tackling the problem.

There are two main types of herbicides used for rush control, MCPA and glyphosate.

MCPA (2-methyl-4-chlorophenoxyacetic acid)
MCPA is a common and effective grassland herbicide which has been used for many years. It is a selective herbicide, with a wide spectrum of weeds controlled and while generally safe to grass swards it can check growth and damage clover and may not be suitable for more species rich swards. It is also water soluble and can take several weeks to breakdown so care needs to be taken when using near the water environment, as MCPA in a water ecosystem has the potential to be catastrophic. This also means that in the poorly drained, or waterlogged soils, where rushes are most likely to be found, there is also a high risk of MCPA finding its way into watercourses through diffuse pollution in the form of run off.

Glyphosate

Glyphosate is a very common systemic herbicide. Unlike MCPA it is not selective making its use on grass swards unsuitable unless the field is being reseeded. One key difference however is its suitability for use in handheld equipment for spot spraying or in a weed wiper, allowing targeted treatment. This has several benefits:

Wetter areas can be reached, by using a quad bike to tow the weed wiper.
Targeted applications reduce the risk to non-target vegetation and the water environment with no drift when weed wipers are used.
Targeted applications also mean lower volumes of herbicide and water are required, further reducing the risk to the water environment.