By Helen Olsen
The development of a high value durum industry across Australia is drawing closer as a major research effort tackles disease and environmental obstacles.
Before growers can claim their prize of a potential two million tonnes a year export industry penetrating one of the highest value grain markets, researchers must first find answers to the crown rot and black point diseases, as well as the limitations of acidic and saline soils and water scarcity generally.
The GRDC has allocated up to $600,000 a year for five years to this end.
In one of the major projects, three researchers - Dr Steven Simpfendorfer, senior plant pathologist at NSW Department of Primary Industries (NSWDPI) at Tamworth, Dr Graham Wildermuth, principal plant pathologist at the Queensland DPI&F, and Dr Ray Hare, principal durum breeder at Tamworth - are jointly working on developing varieties resistant to crown rot, regarded as the single biggest impediment to the durum industry achieving its potential.
Dr Wildermuth says screening has begun on crosses between advanced durum lines and wild tetraploid species that carry some resistance to crown rot: "We have just found crown rot resistance genes in bread wheats and plan to introduce these genes into elite durum varieties."
The premium difference.
Premium durum pool prices are quoted at 13% protein. APW is quoted at 10% protein.
* 04/05 and 03/04 pool prices are estimates as the marketing programs for these pools are still being executed.
^ 02/03 was a drought-affected pool with below average volumes.
New varieties will be tested for crown rot resistance in Queensland and northern NSW on rainfed and irrigated sites. This will provide "a more robust assessment" to speed up the development of resistant commercial durum varieties, says Dr Simpfendorfer.
The NSWDPI team is also studying how crop rotations and soil biology interactions can control crown rot, which can survive between seasons in stubble.
"We have found that stubble breakdown is faster under break crops with denser canopies - the brassicas, faba beans, or sorghum in summer - than under a crop like chickpeas, which do not close over until later in the season," says Dr Simpfendorfer. "We believe the denser canopies provide a more conducive environment for microbial breakdown."
Senior research scientist Dr Mike Sissons, also at Tamworth, is looking for improved resistance to black point. His team has identified durum varieties that carry some resistance and these are being crossed with durum cultivars developed by Dr Hare. "Black point is a visual quality defect that ends up as speckled pasta," says Dr Sissons.
The limit on black point contamination in durum before it is downgraded is tougher than for bread wheat, being three percent compared to five percent.
"It"s not definitely known what causes black point. Researchers overseas think the Alternaria fungus is involved," says Dr Sissons. "In Australia, it"s mainly thought to be a biochemical process, but it is unclear whether it starts with a fungal infection.
We are currently studying the biochemistry involved in black point, and it is complex."
GRDC Research Codes: DAN00061, DAN485.
For more information:
Dr Steven Simpfendorfer, 02 6763 1261;
Dr Graham Wildermuth, 07 4639 8805;
Dr Mike Sissons, 02 6763 1119