Fungal Phytopathogenic Spore First Assessment in an Olive Orchard of Northwestern Spain

Abstract

The most common fungal diseases of Olea europaea are olive leaf spot (Fusicladium oleagineum), anthracnose (Colletotrichum spp.) and cercospora leaf spot (Pseudocercospora cladosporioides). To know the fungal load during the vegetative olive cycle, an aerobiological and phenological study was conducted in an olive grove in North-West Spain. For the aerobiological study, the Spanish Aerobiological Network protocol was followed using a Hirst-type spore trap. The goal of the study was to assess the spore concentrations in the atmosphere of the olive grove and their relationship with the meteorological parameters by applying statistical procedures, including a Cluster analysis, Spearman’s correlation test and PCA analysis. The most abundant spores belong to Fusicladium, registering the double of values than Colletotrichum and Pseudocercospora. The hours with the highest spores’ presence were from 11:00 to 12:00 for Fusicladium and Colletotrichum, and from 17:00 to 18:00 for Pseudocercospora. The Spearman’s and PCA test showed a positive association between temperature and relative humidity with the spores’ concentrations. The combination of meteorological, phenological and aerobiological parameters is a useful tool to understand the ecological behavior of the considered phytopathogenic fungal spores in order to develop futures strategies for the integrated management of fungal olive diseases in areas at the limit of this tree distribution.