A Tekapo sheep and beef farmer is spearheading a campaign to introduce two biocontrol agents for the pervasive weed horehound.
Gavin Loxton has formed the Horehound Biocontrol Group, which is working with Landcare Research in a bid to introduce two moths into New Zealand. These moths have proved successful in Australia.
The putrid-smelling horehound, which resembles mint, is particularly problematic in lucerne crops where it reduces yield. Its prickly burrs also get stuck on wool, reducing its value and further spreading the weed.
Horehound is difficult to control, as herbicides that kill the weed also damage lucerne, clover and the soil.
To help build a case for the moths’ introduction, the Horehound Biocontrol Group is conducting a farmer survey to determine how widespread the horehound problem is and how it is being dealt with on-farm.
Loxton says preliminary responses indicate the weed is at tipping point.
“It’s had exponential growth – it’s doubling every two years – according to surveys I’ve had back. We’ve got areas where we never used to see horehound, starting to be invaded.”
- Take part in the survey at www.landcareresearch.co.nz or contact Gavin Loxton on 027 441 2214.