Investigating Botryosphaeria dieback in walnuts

An emerging risk to the productivity of the Australian walnut industry is the yield loss caused by fungi belonging to the family, Botryosphaeriaceae. The infection caused by these fungal pathogens, also known as Botryosphaeria dieback or Bot, has been implicated in significant economic loss in manyfruit and nut industries including almond,avocado, grapevine, olive and pistachio in many countries (Agusti-Brisach et al., 2019). In Australia and New Zealand, Botryosphaeria dieback has already been recognised as an economically significant disease of grapevine and substantial research has gone into addressing the problem during the last 15 years (Billones & Savocchia 2019).Horticultural industries in Australia, other than walnuts, have started addressing various dieback symptoms, with ongoing research initiatives in almonds and macadamias (Jeff-Ego & Akinsanmi 2019; Oswald et al., 2019). The walnut industry has recently joined this endeavour through a research project that has begun at the National Wine and Grape Industry Centre (NWGIC) at Charles Sturt University (CSU). This article presents a brief update on that project.