Counting the cost

Photo of Dr Hugh Wallwork

Of the three diseases, crown rot, caused by the fungus Fusarium pseudograminearum (Fp) causes the greatest cost to the Australian grains industry. Annual losses due to crown rot are estimated to be $56 million due to reduced yields and increased screenings.

Another species, Fusarium culmorum (Fc) has been found to cause crown rot in higher rainfall areas in Victoria and SA. The Victorian Department of Primary Industries research team, led by Dr Grant Hollaway, has established that both species occur in Victoria and researchers are now investigating if these species will require specific management.

The crown rot fungus survives inside residues from infected wheat, barley, oats, triticale and most grass weeds. This makes crown rot a major limitation to the production of winter cereals as farming systems incorporate more intensive cereal rotations, reduced tillage and stubble retention practices.

The Initiative has highlighted that the disease severity on different crops varies between regions. For example, in the north bread wheat may suffer losses of 20-to-30 per cent and highly susceptible durum wheats up to 60 per cent, while in the south losses average 10 per cent in bread wheat and up to 30 per cent in durum. The Initiative basically consists of two research objectives. Some projects are concentrating on understanding and developing improved variety resistance while others aim to understand and manage the diseases within the farming system.

These approaches are linked under the Initiative and reduced losses to crown rot will come from growers using an integrated management system that incorporates both of these aspects.

[Photo (left) by Brad Collis: Senior research scientist Dr Hugh Wallwork at SARDI.]