Dealing with the scourge of rushes in grassland
Many farmers across the country are fighting an on-going battle against what many would refer to the ‘scourge of rushes’.
On top of this many farmers are now also finding that rushes growing in fields where they never were before as a result of increasingly wet winters.
The soft rush is the most common type of rush in Ireland. Rushes can produce up to 8,500 seeds per fertile shoot every year.
However, they only germinate if conditions are favourable and allow them to do so.
What conditions do rushes thrive in?
Rushes were traditionally a problem on wetter soils, but according to Teagasc are now an everyday sight in drier areas due to poor soil fertility.
It says rushes establish and thrive where grass growth is being limited by some aspect of soil fertility or management.
Low pH would not seem to directly favour rushes but it will hinder grass growth by decreasing nutrient availability.
How to control rushes?
This should be a combination of improving drainage, grazing management, fertiliser application, topping and chemical control.
Encourage grass growth
Maintaining a dense, leafy grass sward will smother out emerging rushes. In this regard, having a fertile soil with adequate levels of nitrogen, phosphorous and potassium along with a suitable pH for grass growth is hugely important.
Avoid any poaching, overgrazing or damage to grass swards.
Fertiliser should only be spread in conjunction with grazing and topping to promote grass growth and restrict the growth of rushes.
The key first step to treating all rushes is the topping/mowing of mature rushes.
Whether you are licking or spraying, topping is advised to promote fresh green re-growth capable of taking in the herbicide. This also helps weaken the food reserves within the plant.
Teagasc says products such as Agroxone 50, Mortone, MCPA 50, Croplink 50 at the correct rate will control rushes but will stunt grass growth.
These herbicides will check white clover and kill red clover.
Using a weed licker Roundup products or Buggy SG is very effective. Take care not to damage grass plants by soaking the carpet on the weed licker too much. Using a sticking agent with these products is suggested.
Avoid spraying in very warm weather as scorching of grass may occur – spray in the cool of the evenings or early mornings.