Weeds threaten the sustainable development of New Zealand’s primary production sectors by reducing yields, quality and profitability, and through environmental impacts from control methods.
Pastoral weeds, collectively, are estimated to cost the NZ economy $1.2 billion p.a. Individually, they can greatly reduce the profitability of pastoral farming. Forestry would simply be uneconomic without cost-effective and environmentally
acceptable weed control.
In our last Newsletter (#2) we reported on a programme of scientific research involving the three CRIs, AgResearch, Scion and Landcare Research, and Plant Protection Chemistry NZ Ltd (PPCNZ). This partnership is working to improve the management of weeds in the pastoral and forestry sectors, and reported that it had:
- Developed herbicide spray adjuvant technologies that enable reduced water rates in forestry without compromising the level of weed control achieved by aerial spraying
- Identified fungi that live inside Californian thistle plants (endophytes)
that can either promote or inhibit the activity of a biological herbicide being
considered for use against this weed, and
- Revealed the threat that yellow bristle grass, an invader from China now
naturalised in the North Island, presents to dairy farms throughout much of
In the current Newsletter we present some examples of how research in Undermining Weeds has quantified the impacts and costs of weeds to forest growers and pastoral farmers.