Biocontrol of Rust Fungi by Cladosporium tenuissimum

This chapter examines whether Cladosporium tenuissimum Cooke, a destructive hyperparasite of rust spores, can be exploited as a BCA of rust fungi. It reports on tests carried out to evaluate C. tenuissimum effectiveness against rusts in the genera Melampsora, Cronartium, Peridermium, Uromyces and Puccinia, focusing on its modes of action, the fine-level analysis of the fungal host–hyperparasite interface, the antifungal compounds it produces, and its ability to reduce disease, both in vitro and in planta. Since effective biological control is impossible without due consideration of the ecology of the BCA, as well as of the other partners involved, and an examination of their spatial relationships and interaction with the environment, attention is also paid to the biological nature of the fungus, in particular to those characteristics that enable it to survive in natural habitats and retain activity under varying environmental conditions.