Rice blast disease

Page last updated: Friday, 9 December 2016 - 2:13pm

Please note: This content may be out of date and is currently under review.

Rice blast caused by fungus Magnaporthe oryzae, is generally considered the most important disease of rice worldwide because of its extensive distribution and destructiveness under favourable conditions.

The pathogen has been detected on rice crops in Western Australia, Queensland and the Northern Territory but remains exotic to the main rice growing regions of south-eastern Australia.

What plants are affected?

Rice blast can affect most of the rice plant with the exception of the roots. The fungus can infect plants at any growth stage.

What do I look for?

Symptoms can be either lesions or spots. Their shape, colour and size vary depending on varietal resistance, environmental conditions and the age of the lesions.

The pathogen infects and produces lesions on the following parts of the rice plant: leaf (leaf blast), leaf collar (collar blast), culm, culm nodes, panicle neck node (neck rot) and panicle (panicle blast).

What damage can this disease cause?

Rice blast is the most important disease of rice worldwide. Under favourable conditions, the disease can results in total crop failure.

What do I do if I find it?

The disease is known to occur in Western Australia. However, it is a notifiable disease within the New South Wales Rice Pest and Disease Exclusion Zone (RPDEZ). This disease is not a notifiable pest outside the exclusion zone.

The RPDEZ includes the shires of Balranald, Berrigan, Carathool, Conargo, Corowa, Deniliquin, Griffith, Hay, Jerilderie, Leeton, Murray, Murrumbidgee, Narrandera, Urana and Wakool. Contact the New South Wales Department of Primary Industries for further information.

How can I control this disease?

Control options are currently very limited within Australia. Overseas rice blast control relies on using resistant rice varieties and/or using registered foliar fungicides. See the APVMA website for current chemical options.

Contact information

Vincent Lanoiselet
+61 (0)8 9368 3263