A new ryegrass that could that could be a game-changer for New Zealand agriculture is being field tested in the United States, because Kiwi scientists aren't allowed to test it here.

The genetically modified High Metabolisable Energy (HME) ryegrass has been shown in AgResearch's laboratories to grow up to 50 per cent faster than conventional ryegrass.

It is also able to store more energy for better animal growth, is more resistant to drought, and produces up to 23 per cent less methane (the largest single contributor to New Zealand's greenhouse gas emissions) from livestock.

AgResearch Principal Scientist Dr Greg Bryan spoke to The Country's Jamie Mackay about the new rye grass and how long it could be before it reaches our shores.


"It is actually a form of enhanced plant breeding and it's used quite widely across the world, but you have to go through the regulatory process and that's more or less what we're doing now."

Further benefits include less nitrogen excreted into the environment by animals feeding on the ryegrass which could result in less nitrate leaching and lower emissions of another greenhouse gas, nitrous oxide.

While New Zealand has not yet approved the release of genetically modified crops, Dr Bryan says it is important that the science keeps our options open, and there is strong scientific evidence on any benefits or risks that policy makers can draw on.

Mackay asks how long could it take before this ryegrass reaches New Zealand.

"Realistically you're looking at another, maybe six years from now," says Bryan.

Listen to the full interview above: