The influence of the storage period on the suppressive capacity of composts enriched with Trichoderma atroviride

Composts can be used to improve soil fertility while controlling soil diseases, contributing to the circular economy in agriculture. Biological control of soil diseases may be achieved by the activity of antagonistic microorganisms, that, by different ways, prevent the development of phytopathogenic microorganisms, being Trichoderma spp. one of the best-known antagonistic fungi. In this work, the evolution of the suppressive capacity during a storage period of one year, was evaluated on two composts enriched with Trichoderma atroviride , against Rhizoctonia solani , Clarireedia spp. and Sclerotium rolfsii in turfgrass ( Agrostis stolonifera ). Both composts, obtained from agro-industrial residues, were enriched with T. atroviride , and stored at room temperature, in the dark. The composts were tested in vivo , at 0, 6 and 12 months of storage, as substrates for turfgrass ( Agrostis stolonifera L. cv. T1) grown in pots. Plants were inoculated with the above-mentioned pathogenic fungi and the incidence and the severity of the diseases, AUDPC and BCI, were determined during the storage period. The highest biological control performance was achieved after 6 months of storage, especially on the composts enriched with Trichoderma atroviride . • Assess the effectiveness of enriched and non-enriched composts in disease suppression. • Evaluate the biological control of Rhizoctonia solani , Sclerotium rolfsii , and Clarireedia spp. • Enriched composts retained suppressive activity even after 6–12 months of storage. • Disease suppression declined after 12 months of compost storage. • Enriched composts offer a sustainable alternative to chemical pesticides.