Dossier on sugarcane downy mildew (species of the genus PERONOSCLEROSPORA) as a disease of sugarcane

Abstract

Sugarcane downy mildew can be caused by one of several fungi in the Peronosclerospora genus, these include P. sacchari (T. Miyake) Shirai & Hara (1927), P. spontanea (Weston) C.G. Shaw, P. miscanthi (T. Miyake) C.G. Shaw and P. philippinensis (Weston) C.G. Shaw. P. sacchari and P. philippinensis are considered to be the most important pathogens of commercial sugarcane crops. In Papua New Guinea there is evidence that an unclassified member of the Peronosclerospora can cause downy mildew: this member is suspected to be closely related to the known sugarcane-infecting species (SRA Final Report).These pathogens invade the sugarcane plant via conidia landing on young buds and via young leaf tissue at the base of the leaf spindle in young shoots. The pathogen invades the stalk tissue and moves through the cane plant to infect newly-developed leaves. With time, these show the characteristic leaf striping symptoms.