Seeking a solution for ratâs-tail fescue
Competitive and invasive, rat’s-tail fescue is notoriously difficult to control with conventional herbicides due to its narrow leaves, which grow to a maximum of only 3mm wide. It is also naturally tolerant to all ACCase-inhibiting herbicides including fops, dims and dens.
With little information currently available to support effective control, Agrovista agronomist Alex Cazaly is calling for improved understanding, and hopes to pool industry expertise to help devise an action plan.
He said: “Rat’s-tail fescue has the potential to become the blackgrass of the North East if we don’t improve our knowledge – it’s prolific and can be the last weed standing.
“I’ve seen populations increase recently across the farms that I manage, particularly when conditions are favourable, such as early-sown direct drilled autumn crops.
“Although there’s no magic solution and we can’t promise to find one over-night, I’m actively investigating ways to improve our handle of the weed, including both cultural and chemical options. It’s a weed that you really don’t want to find.”
Rat’s-tail fescue can produce up to 1800 seeds per head with low dormancy and high germinability. Conventionally found at roadsides, waste ground and embankments, populations are now increasing in arable rotations.
In Denmark where more herbage seed is grown, rat’s-tail fescue has proven a significant problem. Glasshouse trials by the University of Aarhus in collaboration with Rothamsted Research showed that both flufenacet and prosulfocarb had good pre-emergence activity. ALS-inhibiting herbicides such as mesosulfuron with iodosulfuron were most effective post-emergence.
Alex added: “In terms of UK field work, colleagues at Agrovista have found that sulfosulfuron has good efficacy on rat’s-tail fescue in a standing wheat crop, whereas I have achieved strong results using propyzamide in oilseed rape. I would recommend a combination of both pre and post emergence options for optimum control.
“In terms of cultivation, direct drilling works in the weed’s favour, but because it’s shallow rooted, this means ploughing can have a positive effect if you find you do have a problem.
“More interestingly, because the weed germinates in autumn, sowing a cover crop followed by a spring crop has proven to be one of the most effective methods for us. So clever rotation choices alongside topping up with chemistry where required could prove a very solid start in overcoming rat’s-tail fescue.
“But, we are only at the start of finding our way and this could prove a really telling season due to the increase in spring cropping. I think we need to open up more conversations about this weed, work together with growers and communicate potential solutions.”
You can read this update from Agrovista on TFF's AGVendor...
Website - www.agrovista.co.uk