What is the unique selling point of Donegal straw?
Teagasc tillage specialists have confirmed that Donegal straw has a unique selling point - it is free from herbicide-resistant grass weeds, such as blackgrass, spring wild oats and annual meadow grass.
But for how long will this be the case? The exhaustive testing of weed populations by Teagasc is confirming that the challenge of herbicide resistance is gradually spreading from south to north within the island of Ireland.
And straw movements have been identified as the key factor in bringing about this state of affairs.
But a further defining difference, where Donegal straw is concerned, is the strong commitment of tillage farmers in the north-west to use pre-emergence herbicides.
This was a point reinforced by Teagasc tillage specialist, Shay Phelan during his presentation to a meeting of cereal growers held recently at ‘An Grianan’ Hotel near Burt in Co. Donegal.
“Using pre-emergence herbicides on winter cereal crops ensures that grass weeds are challenged at very early growth stages," he said.
“And this approach works equally well where the likes of blackgrass and annual meadow grass are concerned."
The Teagasc expert explained that we have now reached the stage where the spring application of herbicides on winter barley crops will no longer kill-off populations of annual meadow grass.
“The best that can be hoped for is a relatively mediocre degree of weed control," he added.
Meanwhile, Teagasc continues to test weed samples that have been submitted by farmers for resistance to a range of herbicides.
Significantly, a second Irish population of Italian ryegrass that is resistant to glyphosate has been confirmed.
Shay Phelan highlighted the importance of retaining the use of those herbicides that are currently available.
“One new herbicide may come to market later this year with a second product coming to market in 2027.”
While the focus over recent weeks has been on the control of grass weeds in cereal crops, there is a growing expectation that a flush of broadleaf weeds could materialise as soil temperatures start to rise.
This will be a direct consequence of the heavy rains that have impacted on soil conditions since the turn of the year.
The role of sulfonylurea chemistries was identified in this context.
“But it is important that full rate applications of these products are used," Phelan stressed.
“Not taking this approach further heightens the risk of herbicide resistance issues developing in broadleaf weed populations.”
