A GE ryegrass field try in the US has not measured any significant outcomes, according to GE Free NZ.
AgResearch’s one-year trial in Missouri was approved in April 2017, but GE Free NZ says after 17 years of promises, the benefits remain to be seen.
They say there has been no proper safety evaluation of impacts on the environment, or animal health.
President of GE Free NZ Clare Bleakley says farmers are being deprived of help.
"AgResearch must be called to account. The GM ryegrass project is a costly miscalculation and has not improved the quality and resilience of the agricultural system for farmers,” Ms Bleakley said in a statement.
The group says a systems approach based on mixed forage plants and sustainable practices is the best way to add value and resilience that benefits farmers.
But AgResearch says genetically modified ryegrass offers environmental and productivity benefits, though laws in New Zealand might stop it from being grown here.
AgResearch principal scientist Greg Bryan says data from the study shows lower nitrogen excretion from animals, meaning less nitrate leaching and lower emissions of nitrous oxide.
Mr Bryan says while the findings are only preliminary, New Zealand should look the role played by genetically modified organisms (GMOs) as the farming sector deals with issues around nitrate leaching and methane emissions.
Watch the full interview with Dr Greg Bryan above.
Rural Exchange with Hamish McKay, Sarah Perriam and Richard Loe, 5-7am Saturday and Sunday on RadioLIVE