Black Scab of Jojoba (Simmondsia chinensis) in Australia Caused by a Putative New Pathotype of Elsinoë australis

A new disease of jojoba in Australia is described. We have demonstratedthat this disease is caused by Elsinoë australis, a pathogenwhich is normally associated with citrus. This pathogen has not beenfound previously in Australia on citrus or any other crop. The funguscauses a scab on leaves and stems of jojoba and is widely distributed ineastern Australia. Although molecular analysis of the pathogen indicatesthat it is closely related to the natsudaidai and the sweet orangepathotypes of E. australis, glasshouse and laboratory experimentsdemonstrate that it is not pathogenic to a range of citrus cultivarsgrown in Australia. The data indicate that the isolates from jojobarepresent a new pathotype of E. australis.