An aim to lift the national grain sorghum yield through plant improvement is moving ahead with the release of plant breeding material to sorghum companies from part of the Department of Primary Industries (DPI) sorghum breeding program.

Project leaders Bob Henzell and David Jordan of the DPI Hermitage Research Station, near Warwick, said it was too early to know whether the germplasm could be successfully incorporated into agronomically acceptable varieties, although initial results were encouraging.

They said the release of the germplasm to seed companies was certainly a step ahead in the commercialisation process and getting higher yielding hybrids into growers' fields, with flow-on benefits to the community.

The germplasm is a product of the Grains Research and Development Corporation-supported project to attempt to significantly lift the national grain sorghum yield through the use of exotic sorghum varieties via selection and breeding.

 "A 1 per cent a year increase for five years would certainly be a wonderful result for the industry," they said.

The project involves the assessment of a large number of sorghum lines collected from throughout the world, with suspected high yield potential in a genetically diverse background being the assessment criterion.

Selected exotic lines are then crossed and backcrossed to locally adapted, midge resistant and stay-green lines with selection then in the progeny of these crosses.

It is not yet possible to know how big a yield increase will be achieved, or even whether a significant yield increase is possible.

Dr Jordan's work in transferring yield genes from wild sorghum to grain sorghum is part of this project.

They said this season's sorghum breeding trials had been sown at the Biloela Research Station, with planting underway at the Hermitage and Gatton research stations and on farms in southern and central Queensland and northern New South Wales.

Dr Henzell said the sorghum breeding program's emphasis on yield was a sequel to earlier work on midge and drought resistance, with those characteristics now almost an imperative in commercial hybrids in Australia, a unique situation internationally.

"We've almost gone as far as we can in that direction, so for several years we've been concentrating on yield improvement using a broad gene pool of plant material."

He said like all plant breeding the research was a long-term project.