A group of the country's leading scientists is looking at how to tackle the agriculture and forest industries' billion-dollar weed problem.
The Crown research institutes AgResearch, Scion and Landcare have teamed up with a private research company, Plant Protection Chemistry, to help farmers and foresters come up with ways of sustainably managing weeds.
The programme leader, Graeme Bourdot of AgResearch, says weeds cost the pastoral industry more than $1 billion a year and the forestry sector more than $100 million, in lost production and control.
He says scientists want to understand weeds better, so they can manage them more effectively.
Dr Bourdot says some of the initial work is looking at the pasture weeds California thistle and Chilean needle grass.