WELLINGTON – Newly-developed, fast-growing grasses that help make farming more productive could be the next generation of
environmentally-damaging invasive weeds, said a co-author of an international study.
As the global demand for dairy products and beef escalated, farmers were increasingly seeking ways to reap greater productivity from their pastures with grass varieties that produced more seeds and were resistant to drought, pests, grazing and disease, said professor of plant biosecurity at Lincoln University Philip Hulme.
He said in making grass varieties more robust, the developers were creating new varieties that could invade adjacent areas and spread across the landscape or interbreed with existing invasive weeds.
Pasture species such as ryegrass and fescue were already regarded by New Zealand’s Department of Conservation as environmental weeds.
“Pasture is big business in New Zealand and a large part of our economic success arises from agribusiness developing ever more productive or persistent varieties. As a result there is a clear conflict between economic and conservation outcomes,” said Hulme.
“It is probably those varieties being developed for greater persistence, especially in the face of drought, that might pose the greatest future risk,” he said.
The researchers have made four biosecurity recommendations for governments, industry and researchers: governments should manage a list of prohibited varieties; develop a weed risk assessment; ensure rapid detection and control of invasive weeds; and develop an industry-pays system. – Bernama