Septoria resistant varieties: WA seeks 'icing on the cake' by Brendan Cant

Septoria nodorum blotch, Western Australia's major leaf disease of wheat, may not be a problem for growers in other states. Nevertheless, it significantly cuts Australia's total wheat production every year.

That's because WA contributes up to 40 per cent of the nation's export wheat and S. nodorum annually reduces WA yields by up to 15 per cent (up to 50 per cent in severely affected crops in epidemic years).

Hyden wheatgrower and GRDC Western Region panel member Dale Baker said S. nodorum cost WA growers more than rust or drought because it took a percentage of the crop every year.

"It's the biggest disease WA wheatgrowers face and every year it means losing the icing on the cake," he said.

Small wonder that a research project supported by growers through the GRDC is pushing hard to develop resistant varieties.

Project supervisor and Agriculture WA Senior Plant Pathologist Robert Loughman said 10 per cent of the 1,200 different seedlines screened for resistance to S. nodorum in 1997 were advanced for more detailed screening, with a further 1,500 to be assessed this year.

The global variety search has imported wheat germplasm from Canada, France and Mexico and established collaborative links in South America.

"The project augments existing breeding efforts for the development of 5. nodorum-resistant wheats. Improvements are being built into new wheats on a continual basis."

Dr Loughman said while S. nodorum can respond positively to some fungicide treatments, improving varietal resistance was the preferred option.

"Any pesticide use has an obvious cost attached and also the cleaner and greener we can make our food crops the better we will be able to meet the demands of an increasingly discerning global market," he said.

Program 1.6.3 Contact: Dr Robert Loughman 08 9368 3691