Preliminary investigations into the life cycle of Ventruia inaequalis (Cooke) WINT. in South Australia.

Abstract

Investigation into the possible sources of primary infection by the fungus Ventruia inaequalis (Cooke) Wint. in spring has been carried out. The results present new information on the life cycle of the pathogen under South Australian conditions. Sources of primary infection, such 'as lesions on one-year-old wood or overwintering superficial conidia on the trees, do not appear important. Bud-scale infection of dormant buds has been shown, and its relative importance is discussed. Ascospores are the most important source of primary infection. Their period of discharge extends to a later date than previously reported for South Australia and is considered in relation to leader shoot and late summer spot infection.