Securing the world’s food supply

The Plant Breeding Institute is continuing work begun in the 1920s by working closely with growers to track and prevent cereal rust outbreaks in Australia and across the world.

Colin Wellings

The University of Sydney has been leading the battle against rust diseases in cereal for almost 100 years. From the work of Walter Waterhouse in the 1920s and beyond to the internationally-recognised research of the Australian Cereal Rust Control Program (ACRCP), the University has worked closely with growers to combat and develop resistance to cereal rust, helping to provide improved global food security.

In the 1920s Walter Waterhouse, who laid the foundations for current knowledge of cereal rust, would ensure his University of Sydney students were aware of the devastating personal losses suffered by farmers following plant disease epidemics. The Plant Breeding Institute at the University is continuing the work of Waterhouse and his successors, its researchers maintaining a close relationship with growers through the ACRCP.

Half the funding for the Program is provided by growers, through the Grains Research Development Corporation (GRDC) and researchers in the program place great importance on achieving practical outcomes for growers.

“As growers are directly funding the work we do, we try to focus on providing practical outcomes that are of value to them”, said Dr Colin Wellings (above), a specialist in wheat and barley stripe rust and stem rust in oats.

Wellings is recognised as “the face of the ACRCP to the Australian farmer”. He leads the extension work in passing on relevant information to farmers and technical consultants. This includes advice on suitable varieties to plant, the application of fungicides and the monitoring of crops.

Cereal rust types

Rust is caused by fungi. It is named thus due to diseased plants showing rust-coloured orange patches on the infected plant parts. There are three rust diseases prevalent in Australia: stripe, stem and leaf rust. Rust can cause significant losses to wheat crops.

The ACRCP focuses on controlling rust diseases through the development and cultivation of wheat varieties with in-built resistance. Researchers are continually monitoring the rust pathogens, akin to monitoring changes in human influenza, and developing new resistance genes to combat pathogen evolution.

“Rust can be quite dramatic, it can decimate food supply. In the 1880ss Australia suffered a disastrous series of epidemics. Australia was importing wheat from New Zealand, such was the damage caused by the rust. William Farrer and colleagues at the turn of the nineteenth century were able to make substantial progress in improving disease tolerance and flour quality in commercial wheat varieties. However the rusts continued to cause sporadic problems,” said Wellings

Waterhouse began his work at The University of Sydney in the 1920s and this has continued unabated to the present day. Rust epidemics remained a threat and certain seasons were notably more severe than others. In 1973 a major stem rust epidemic developed in the southern regions of eastern Australia.

“Before the 1973 outbreak the University was working with growers in northern NSW and south east Queensland. These areas were relatively untouched by the 1973 rust, mainly due to the work researchers and growers had achieved together. The losses were so severe in the southern states that the economic scale has been estimated to exceed $2 billion on current value. The impact on the national GDP would have been significant”, said Wellings.

After the 1973 outbreak the University was invited to expand its program of rust research and begin working with growers across the nation.

“There has not been a major stem rust outbreak in Australia since 1973 and this is in large part because the Program and its partners has never dropped the ball in keeping its focus on rust diseases”, said Wellings.

In the late 1990s there was a significant outbreak of rust in East Africa where a new rust pathotype emerged from Uganda giving rise to concerns that resistance genes bred into cereals could be damaged. Fearing it could spread to other bread basket areas and threaten international food security, a multinational effort to combat this new strain was launched. Professor Robert Park, a Senior Fullbright Scholar in 2010 and the GRDC Chair of Cereal Rust, played a leading role in this effort.

Currently the ACRCP is encouraging farmers to prepare for potential rust threats through the Rust Bust campaign. The recent wet summer period, following a season of increased rust activity in eastern Australia in 2010 , has set the greatest potential for a rust outbreak in 40 years.

“We are continually scrambling to keep abreast of new pathotype developments and pass information on to growers and wheat breeders. Rusts spread very easily – through wind or on the clothes of travellers – and the nature of human movement around the globe means new strains of rust can be transported much quicker than in any other time in history ”, said Wellings.