Advancing Conservation Biological Control: A Multidimensional Perspective on Microbial Suppression of Plant-Parasitic Nematodes

Using microbes to control plant-parasitic nematodes is often proposed as a sustainable management practice and commonly referred to as microbial control. Microbial control is generally divided into two approaches, namely adding cultured, non-native microbes to a field (= ‘augmentative biological control’) and stimulating microbes that are already present in the soil (= ‘conservation biological control’).  In this thesis I aimed to advance our understanding of microbial control of plant-parasitic nematodes, principally within the framework of conservation biological control. We show that soils that naturally suppress potato cyst nematodes occur in the Netherlands, and that this suppressiveness can vary within a single field. Our analyses also reveal that fungi that can suppress nematode infestations are present in most soils around the globe and are particularly prevalent in agricultural soils. Furthermore, we expanded methods relevant to investigating microbial control of nematodes, such as the molecular characterization of nematode communities at the species level.