Septoria tritici blotch (STB) is an important stubble borne foliar disease of wheat in Victoria, Australia. This disease has increased in importance in the high rainfall cropping regions during the last five years, even though it has been well controlled in Victoria for the last 30 years through the use of partially resistant wheat varieties. The increase in STB in the high rainfall zone has been favoured by stubble retention, intensive wheat production, susceptible cultivars and favourable disease conditions.