There is currently no scientific evidence to support the suggestion that fungi rather than the bacterium Xylella fastidiosa are the primary cause of the olive quick decline syndrome observed in Apulia, southern Italy. That is the main finding of an analysis carried out by EFSA of new studies and other information submitted to the Authority.
In addition, there is no published evidence that treatment of fungal disease will reduce the establishment, spread and impact of Xylella, although good orchard management is generally beneficial for plant health.
The papers examined by EFSA observe that tracheomycotic fungi are often associated with olive wilt and could also be involved with olive quick decline syndrome. However, the research neither states nor demonstrates that these fungi are the primary cause of olive decline.