Wheat stripe rust (caused by Puccinia striiformis f.sp. tritici,= Pst) in Australia was first detected in 1979, with severe epidemics in the mid 1980s triggering the first wide-scale application of fungicides for foliar cereal disease control. Wheat breeding, which has historically employed resistance as the key strategy for rust control in Australia, responded to this challenge and progressively released commercial varieties that provided crop protection for 20 years. However, an exotic incursion of a new pathotype in 2002 had dramatic implications for stripe rust management. Widespread epidemics in ensuing years witnessed increasing fungicide applications as a direct consequence of inadequate resistance in commercial varieties.

Disease management is focused on strategic fungicide applications to support currently inadequate resistance, with the medium-longer term focus on re-establishing resistant varieties as the control option of choice. The paper will briefly review fungicide control, and will emphasize the principles and methods of achieving stripe rust resistance in the Australian Cereal Rust Control Program (ACRCP).

Chemical crop protection decisions seek to balance crop loss risks with economic imperatives for profitable wheat production at world market prices. Choices range from pre-plant (seed dressings, fungicide amended fertilizer) to foliar applications using ground rig or aircraft platforms. Fungicides include cheaper off-patent triazoles to recently available strobilurin mixtures.

The ACRCP encompasses an annual pathogen survey, genetic studies of resistance, and germplasm enhancement and screening. Pst surveys over 25 years have shown that exotic introduction and subsequent pathotype evolution have had dramatic effects on variety response. Genetics of host resistance has been directed at understanding the nature and diversity of currently deployed resistances, and the discovery, characterization and development of new resistance sources. The integration of data and materials arising from pathogen surveys and host resistance research allow directed decisions in germplasm enhancement activities and screening of breeding populations.