Evaluation of Trichoderma asperellum ICC012 and T. gamsii ICC080 to protect almond pruning wounds from infections caused by fungal trunk pathogens

[EN] This study evaluated the potential of Trichoderma asperellum ICC012 and T. gamsii ICC080 to protect almond pruning wounds from infections caused by three major almond trunk pathogens: Diplodia seriata, Eutypa lata, and Neofusicoccum parvum. Dual-culture antagonism assays and two in planta wound protection trials were conducted to assess their efficacy. In the first trial, treatments with T. asperellum ICC012 + T. gamsii ICC080 were applied one or seven days before or after pathogen inoculation to test the impact of application timing, while the second trial focused on preventive strategies, comparing single versus double applications prior to inoculation. Both Trichoderma strains alone and mixed were able to inhibit pathogen growth in vitro. Experiments in planta showed that only pre-infection applications significantly protected pruning wounds, though their efficacy differed by pathogen and treatment strategy. Protection was highest against E. lata and D. seriata, in which a single treatment prevented infection, whereas N. parvum proved more challenging; only a double preinoculation application markedly improved its control. Our results demonstrate that preventive wound protection by T. asperellum ICC012 + T. gamsii ICC080 is essential for effective control. Incorporating these biocontrol agents into almond orchard management can substantially reduce trunk disease infections and limit reliance on synthetic fungicides in Mediterranean production systems.