It's been a long time coming, but graingrowers in northern New South Wales and southern Queensland have another pulse option for their rotations - field pea varieties adapted for their region.

The first such variety, the dun type Yarrum, will be available for commercial planting this coming winter season and the second, the white seeded Boreen, will follow in 2006.

Released by Sunprime Seeds, Yarrum and Boreen have emerged from an eight-year evaluation of field pea germplasm at the University of Sydney's Plant Breeding Institute at Narrabri.

Steve Moore, officer in charge of the institute, told the recent Grains Research Update in Goondiwindi naming and the release of more adapted field pea varieties was possible over the next two years.

More than 240 industry advisers and leading farmers attended the Update, organised by the Grains Research and Development Corporation (GRDC) in collaboration with its research partners - the New South Wales and Queensland Departments of Primary Industries, CSIRO, the universities and private consultants.

"In its search for field pea varieties suitable for commercial production in northern NSW and southern Queensland, our program identified temperatures and season length, flowering time, plant type, standability and waterlogging as the main challenges to adaptation," Mr Moore said.

"The big one was temperature, and its interaction with flowering and seed set. The growing season for the region is typically cool to very cold winters followed by the rapid onset of high temperatures in September.

"While sub-zero frosts often occur at Narrabri as late as the end of September, the last high frost risk is August 12.

"Field pea will cease flowering when the maximum temperature rises consistently above 25 degrees and at Narrabri that also means towards the end of September. "

Mr Moore said a northern field pea's flowering period had to be after early August and before the end of September. The plant had to have flowered and podded in that time.

Yarrum had vigorous winter growth, was semi-leafless and relatively indeterminate in flowering. Its short growing season - 80 to 90 days to flowering - meant it could be planted in mid-May and harvested the third week in October.

Mr Moore said while heliothis and viruses were identified as possible constraints to field pea production in the north, the major one was powdery mildew and they had been able to find a strong source of resistance to include in new varieties.

New South Wales Departments of Primary Industries pathologists were collaborating with the Plant Breeding Institute in the study of viruses.