Farmers and growers are being asked to keep their eyes peeled for a fungus that could help pave the way for a new method of killing Californian thistle.
Californian thistle is widespread throughout New Zealand and is regarded as one of the worst pasture weeds on farms.
Future Farming Centre head Charles Merfield said Canadian researchers had developed a biological herbicide based on white tip fungus which was proving successful against Californian thistle overseas.
White tip fungus had never been identified in New Zealand but Mr Merfield hoped farmers would spot it, as that could make the introduction of the bio-control into this country a whole lot simpler.
"They have some very substantial barriers to getting it into the country," he said.
"So if we can find if this disease is already present, naturally occurring, in New Zealand, that could significantly simplify the amount of work required to get the herbicide into the country and get it able to be used."
As the name suggested, the white tip fungus made the tips of the thistle appear bleached when the fungus was present.
Meanwhile, the Environmental Protection Authority was calling for submissions on another fungus which was being proposed for release in the country.
Grasslanz Technology and AgResearch have applied to release the Neotyphodium fungus, which they believe will improve the resistance of rye corn and other cereal crops to pests and diseases.
