Ecology and management of fungal diseases in strawberry cultivation

Last few years, there is an increasing problem with fungal pathogens in the strawberry cultivation, in particular with Phytophthora cactorum, Phytophthora fragariae, Verticillium dahliae en Pestalotiopsis longisetula. Infection of strawberry plants with one or more of these pathogens results in considerable yield losses of up to 50%. Commercially available biocides show little or no efficiency in preventing these fungal diseases. Therefore there is an urgent need for an integrated pest management strategy to tackle the problem caused by these fungal pathogens in the strawberry cultivation. In a first part specific qPCRs are developed to detect and quantify the target pathogens. These techniques are subsequently used to monitor the spread of these pathogenic fungi in the field in order to assess the correlations between fungal concentrations and infection rate. Ultimately this leads to the determination of action limits, which provide a useful management tool for the growers. In addition the microbial communities of infested and non-infested fields are examined in order to investigate the relationship between the presence of particular indicator organisms and increased or decreased risks for disease incidence.  

The second part focuses on biological control, in which the efficacy of commercially available products is tested. In addition, a screening is carried out to search for new bacterial and/or fungal strains showing antagonistic activity against the target pathogens. Subsequently the mode of action of the best performing candidate biocontrol organism is investigated.