Published on 21/01/2026
Adama New Zealand applied to import or manufacture the herbicide, Tower, which contains the active ingredients chlorotoluron at 250 g/litre, pendimethalin at 300 g/litre, and diflufenican at 40 g/litre.
Adama says the combination of different active ingredients should reduce the risk of resistance developing and that few herbicides can control grass weeds in cereals without damaging the crop.
“This approval means wheat and barley growers have another tool in their toolbox to help protect crops vital to New Zealand’s primary sector,” says Dr Lauren Fleury, acting general manager for hazardous substances and new organisms.
The combined wheat and barley industry contributes around $300 million a year to the NZ economy.
Almost 100,000 hectares of NZ land is used for wheat and barley production.
Tower contains chlorotoluron, a chemical new to NZ, though it has been approved in the UK and Europe.
It also contains two other active ingredients already approved and available for use in NZ- pendimethalin and diflufenican.
“The decision to approve the import or manufacture of Tower was made following a rigorous assessment and consultation process,” Fleury says.
“This decision is the latest for the EPA, which continues to work hard and has reduced the queue of hazardous substance applications. The EPA has set ambitious assessment targets for the coming year, including increasing the number of assessments for substances containing new active ingredients.”
Tower can only be used by professionals in commercial settings, using ground-based application, after sowing and before wheat and barley plants emerge.
It has subsequently received ACVM approval and can now be commercially sold and used in NZ.