Tree endotherapy with Trichoderma spp. against the agent of chestnut nut rot Gnomoniopsis castaneae

An emerging fungal disease caused by the ascomycete fungus Gnomoniopsis castaneae (syn. Gnomoniopsis smitholgivyi) is responsible for nut rot of sweet chestnut. The disease is currently impacting chestnut production in several Italian regions, with severe economic losses in a marginal cultivation with low income such are in fact the fruit chestnut groves. The aim of this work was to test the development and optimization of a biological control method against G. castaneae based on trunk injections with Trichoderma species. Trichoderma species and strains were selected in laboratory pre-trials, in which their effectiveness against G. castaneae was analyzed in an in-vitro dual culture system, and injected in the stem of fruit chestnut trees. Results showed a reduction of G. castaneae infection in treated stands compared to controls (untreated chestnuts), proving endotherapic treatments with BCA to be a promising control strategy against G. castaneae infection.