Green mold disease, caused by Trichoderma spp., is the most harmful disease for edible mushroom production, such as champignons. The disease affects yield, fruit body formation, and can be spread through contaminated tools, substrate, clothing, air and insect vectors. Considering the significant degree of yield loss in mushroom production due to the appearance of the mentioned disease, the need for early, rapid and specific detection of the presence of Trichoderma spp. in casing soil is exceptional. In this study, we aimed to examine casing soil as a possible source of Trichoderma contamination, as well as to develop a novel point-of-need assay for its early screening.