According to Enable Conservation Tillage (ECT) advisor, John Mahon, grassland weeds represent a problem for the entire tillage sector.
Speaking on the most recent edition of the Tillage Edge podcast he said that limited crop rotation and a reliance on single chemistries has helped create the problem over many years.
“This has been very much the case where spring barley has been grown continuously on the same land,” Mahon explained.
Grassland weeds
Mahon cited wild oats and bromes as being among the greatest grassland weed challenges now confronting Irish growers.
He continued: “Bromes are there all the time, particularly in continuous winter barley. It is creeping in from the headlands.
“There is also evidence to show that non plough-based systems are giving the brome a better chance of survival.
“But there are solutions out there including the use of stale seed beds, break crops, grass margins and adapting rotations accordingly,” he continued.
Mahon pointed out that blackgrass is becoming more prevalent, adding: “The only advice for it is to have a zero tolerance policy. If farmers see it, they have to destroy it before the seed becomes viable.
“It’s such a prolific plant; growers can’t allow it to get established and build a seed bank, particularly in a non plough-based system.”
Where canary grass and other spring germinating grassland weeds are concerned, Mahon confirmed that effective chemistries are available to deal with these issues.
“In many instances where problems of this nature arise, it’s the case that the farmer has actually missed spraying it,” Mahon added.
“But when this happens a seed bank will start to build up.”
But there will always be some new challenge arising when it comes to dealing with grassland weeds in tillage systems. Mahon referred to Italian ryegrass and rat’s-tail fescue in this context.
Cultural control
The ECT advisor went on to confirm that the cultural control of weeds will rise in prominence during the period ahead.
“It’s our way of controlling the herbicide chemistries that we have,” he stressed.
“And we must be serious in getting this message out there with growers. There is not an endless stream of new products coming.
“So we have to look after what we have. Farmers are aware of individual cultural control methods, like rotation.
“Ironically, the three-crop rule that was introduced as part of the single payment support system was a saving grace on many Irish farms, where herbicide resistance had started to become a real issue,” he concluded.
Image: O’Gorman Photography