Survival over summer of Rhynchosporium secalis in host debris in the field

Abstract

The ability of Rhynchosporiurn secalis to survive over summer in plant debris and to produce inoculum for scald disease development in barley crops was investigated. Viable inoculum was recovered from dead host leaves (Hordeurn vulgare and H. leporinurn) kept on soil surfaces in the field for up to 30 weeks after crop maturity in a range of South Australian barley-growing environments. When infected leaves were suspended 30 cm above soil surfaces, the fungus survived for up to 37 weeks. When buried 6 cm below soil surfaces, the fungus survived for 20 weeks. Following an initial decline in infectivity of inoculum over summer, infectivity increased during autumn to levels similar to those obtained at the start of the trials.