Glyphosate-tolerant or Roundup-Ready (RR) lucerne, developed by Forage Genetics and Monsanto, was first available in the United States in 2005 and is set to be re-released there again later this year.

But the cost of research and deregulation to bring it to Australia is simply too great.

RR lucerne is genetically modified and according to the manager of the international division of Forage Genetics, Bill Knipe, the market for the product in Australia may not yet be large enough for his company together with Monsanto and marketing partners to apply to have it deregulated in Australia.

Monsanto and Forage Genetics own the patents for RR lucerne and it would be a decision made by those two companies if the plant was to come into this country.

PGG Wrightsons agronomist, Reg Hill, said RR lucerne would have a great market in Australia depending on the price because of its production convenience versus conventional lucerne, which requires various chemical treatments to keep weeds at bay.

"Life would be much easier for growers if it was available but it is in part a commercial decision but also a regulatory decision by others not to bring it in," Mr Hill said.

"It just is not feasible at the moment given the costs involved with research and deregulation."

RR lucerne is presently undergoing an environmental assessment through the US Department of Agriculture after court action in California challenged its application process in 2005 (the challenge was not based on technical grounds).

Lucerne promises to not only help bridge the summer-autumn feed gap but also provide high protein feed to finish lambs, provide a fire break and increase soil nitrogen in a crop rotation.

Naturally there is a cost for this super-legume.

Lucerne must be managed carefully, its establishment must be right and ongoing winter cleaning is also paramount.

Mr Knipe said the potential for further genetic engineering of lucerne was enormous.