Industry response to last year's announcement
glyphosate-resistant weeds had been identified in New Zealand
for the first time has been positive and supportive,
according to the leader of a project working on avoiding
Mike Parker from the Foundation for Arable Research (FAR),
who leads the avoiding glyphosate resistance project, said
representatives from primary sectors as well as regional
councils and roading authorities were working together to
identify and deal with existing cases, and to develop
strategies to minimise the number of new cases.
''Last year's announcement has really been a timely reminder,
and it is great to see all of these groups working together
to find solutions to what is, potentially, a very serious
''Glyphosate is environmentally benign and cost effective,
and as such has become the most frequently used herbicide in
New Zealand. If we were to lose it from the list of available
products, farmers, councils and roadside managers would be
looking at substantial environmental and financial impacts,''
Mr Parker said.
Since the initial discovery of glyphosate-resistant annual
ryegrass on a vineyard in Marlborough, four more cases, also
on Marlborough vineyards, have been confirmed by weed experts
Kerry Harrington, of Massey University, and Trevor James, of
Dr James said the four latest cases were investigated last
year, but since December's announcement more reports of weeds
surviving glyphosate treatment had been coming in from all
around New Zealand.
''All of these cases need to be investigated, although it is
likely that many will be the result of application misses or
errors, rather than resistance. When glyphosate is applied in
the wrong conditions, or when spray penetration is
insufficient to reach below canopy plants, this is counted as
''A key part of our research project is the development of
clear, sector-specific recommendations for the use of
glyphosate. We hope that these best management practices will
reduce the number of glyphosate failures and also the number
of cases of resistance, which is generally linked to overuse
of the chemical.''
Dr James said testing for resistance was taking around three
months, as individual plants had to be transported to a
quarantine laboratory, split into tillers, grown out, and
then treated with varying rates of glyphosate.