Teagasc has confirmed that the challenge of ‘uncontrollable grass weeds’ within crops remains a major challenge for tillage farmers.
This is particularly so, where the use of minimum cultivation techniques, is concerned.
The recent Enable Conservation Tillage (ECT) project was developed to communicate the latest thinking on how these techniques can be applied in ways that respond to the grass weed challenge.
In the past, a number of Irish growers experimented with min-till, direct drill or no till systems, but were unsuccessful.
Many identified the difficulty of controlling of grass weeds as one of the primary reasons for reverting to plough-based systems. The ECT project, however, highlighted a number of monitor farmers, who had successfully made the change.
One of the big take-home messages from the project, was the fact that that the establishment system is only part of the puzzle -more integrated pest management (IPM) tools must be incorporated into the farm system for the practice change to work.
According to Teagasc tillage specialists, good rotations, avoiding compaction, learning from mistakes and reducing grass weed problems through cultural control methods, as well as herbicides, are all important parts of a successful transition.
Blackgrass
Herbicide-resistant blackgrass populations are already creating challenges for Irish tillage farmers.
Experience at Teagasc Oak Park is a;lready confiorming that that blackgrass can become an issue unless growers are vigilant.
In 2020, as part of a plan to increase biodiversity on the farm, wild flower margins were planted. Significantly, the Oak Park farm manager identified blackgrass plants in one field.
A plan was put in place to eliminate the blackgrass. Glyphosate was used to burn off the affected margins, multiple stale seed beds were applied and the margin in question was ultimately planted with grass.
Italian ryegrass
Italian ryegrass is another grass weed that is starting to become an issue on many Irish farms.
The problem can be traced to the autumn of 2018 when tillage farmers were paid to establish forage crops after harvest to produce much need forage for livestock farms.
Some of this Italian ryegrass has now become a problem with many herbicides struggling to control it.
In the summer of 2023 a group of farmers who are participating in a European project called IPMworks visited Denmark where Italian ryegrass has overtaken blackgrass as the main grass weed problem.
With no herbicide control available, their only option is cultural control methods such as whole crop, land swapping or crop destruction.