Use of organic composts to suppress bentgrass diseases in Agrostis stolonifera

•Composting products have a high agronomic value, with suppressive capacity.•Our objective was to evaluate the role of composts inhibiting fungal diseases.•Fungi with high rates of growth inhibition, namely T. atroviride, were isolated.•Evidence demonstrated that composts reduced the severity and incidence of diseases.•Those composts with chitin promoted a greater diversity of antagonists.