The latest trials of a Graingene-bred water-efficient wheat variety have shown it has the potential to add millions of dollars to the value of the New South Wales (NSW) wheat crop.

In 12 independent field trials held across New South Wales in 2003, Drysdale wheat yielded an average of 23 per cent more grain than the current recommended variety Diamondbird, despite very dry conditions.

"If Drysdale was sown throughout southern and central New South Wales, it could add hundreds of millions of dollars to the average crop value," says CSIRO's Dr Richard Richards.

"Based on 2003 crop data, this could earn farmers over $100 per hectare extra income and mean the difference between a good or a bad year."

While these results demonstrated Drysdale's performance in dry years, in further trials it has also consistently been one of the best varieties under irrigation.

Drysdale was developed using a new scientific selection method known as DELTA carbon, based on measuring a plant's carbon isotope signature. A second variety bred using the technique, Rees, was released last year and has performed well in northern NSW and Queensland.

"By using this revolutionary technique, we were able to breed varieties of wheat that more efficiently exchange atmospheric carbon dioxide for water during photosynthesis," Dr Richards says.

Yield data on Drysdale was gathered in AgriTech Crop Research field trials, commissioned by the Grains Research and Development Corporation (GRDC). Full trial data are available on the AgriTech website.

Graingene, a joint venture between AWB Ltd, the GRDC, Syngenta and CSIRO Plant Industry, released Drysdale in 2002. The variety was developed in collaboration with NSW Agriculture and is being commercialised and distributed by AWB Seeds. The DELTA carbon technology was developed in collaboration with the ANU.