DEMATIACEOUS FUNGI, A CAUSE OF POOR ROOT HEALTH IN SUGARCANE

THE Australian sugar industry generally employs a sugarcane monoculture system. This has led to a growth limitation associated with sub-optimal soil biological, chemical and physical characteristics; the condition has been called yield decline. Research over a number of years has shown soil biological factors make a very significant contribution to this condition and poor root health is a key feature of roots growing in yield decline-affected soils. Extensive isolation studies were therefore conducted to determine what organisms are associated with poor root health and what effect soil treatments that promote plant growth have on root and rhizosphere fungal colonisation. This paper reports on a group of fungi, dematiaceous or dark sterile fungi, shown to be pathogenic in glasshouse pathogenicity experiments. The results are consistent with observations made elsewhere in yield decline research.