Fermanagh and Tyrone farmers have been shown various methods of controlling rush. Rush that has not been treated, could make fields ineligible for subsidy payments.

A Rush Management Event took place at Crom Estate on Thursday, one of two held in Northern Ireland. The other took place at Greenmount Campus’s hill farm at Glenwherry.

Graeme Campbell, from CAFRE’s Crops, Horticulture and Sustainability Development Branch, explained how the rush had become a major problem throughout Northern Ireland over the past few years.

As it was a herbaceous, low nutrient value plant often associated with poorly drained soils, and in areas of high rainfall and heavy clay conditions, there was a need to control it.

However 10 per cent of the rush presence in a field must be retained if there is evidence of breeding wader habitats there.

Because of the evasive nature of the rush plant, it has to be controlled to make it accessible to grazing stock.

Graeme is in charge of four demonstration sites across Northern Ireland; Glenwherry, Belfast Hills, Oxford Island and Crom Castle. The CAFRE Rush Technology Project which is expected to run up to four years was established across five sites in 2014 to demonstrate different rush control methods and establish which methods were most effective.

Graeme said that looking at the sites, rushes had grown more in the last six weeks than during any other period of the year. Rush infestations were treated to various methods of control, one a control site where no treatment was given, spraying only with Headland Spear MCPA, weed wipe only, a combination of cutting and weed wiping and cutting only with a flail type machine.

There were restrictions with the use of MCPA which can no longer be used with a weedlicker. Use of MCPA with weedlickers have been linked with presence of the chemical in ground water.

Only a glysophate product can be used in weedlickers.

They have also looked at lime applications as it is thought an increase in ph will reduce rush presence.

Findings so far have found glysophate very effective when used after the rushes had been cut a number of months previously but follow-up treatment was critical.

The plot where rushes were first cut and later licked with a weed wiper showed greatest reduction in rushes in the following year at all sites. At the Greenmount site, the percentage of rush reduced from 81 per cent to 20 per cent. The concentration of chemical used was 4.8 litres per hectare. Stock should be kept off land treated for 14 days.

Grainne McCarney from DARD demonstrated the effects of liming, especially on soils with a low ph of 5.1 to 5.5 Two tonnes of ground limestone per acre lowered the acidity and improved ph so that the grass or crop could take up nutrients more effectively.