MCPA was the most common pesticide exceedance found in Irish water supplies in 2020. Exceedances rose from 82 in 2019 to 91 in 2020.

It is a commonly used pesticide by farmers, gardeners and amenities for the control of things like rushes, thistles and garden moss.

Good stewardship

Good stewardship is essential to prevent these exceedances in water supplies. For example, if using pesticides, make sure to use the correct rate, adhere to the correct buffer zones and clean the product’s can correctly.

On farms, soft rushes grow in damp and waterlogged soils. This makes control difficult, as spraying on wet soils can result in pollution of waterways.

Weed wipers

In line with good stewardship, farmers are being asked to consider weed wipers for the control of rushes. Weed wipers allow for product to be applied to individual plants.

As a result, glyphosate can be used, as the weed wiper will target the application to one plant and not the grass around it.

As part of its MCPA stewardship, Nufarm has shown that weed wipers with a rotating brush can offer 75% control of rushes when applying AST glyphosate. Once the rushes have died off, after approximately one month, they should be cut and removed to allow the grass to grow.

Farmers should also try and prevent rush growth where possible through drainage or sub-soiling and maintaining soil at a pH of 6.5 to promote grass growth. Grazing in the spring and summer is also recommended when soil is in its best condition. Soil should not be over-grazed or poached.