EVALUATION OFTHE ANTAGONISTIC ACTIVITY OF INDIGENOUS TRICHODERMA SPECIES AGAINSTCOLLETOTRICHUM GLOEOSPORIOIDES, THE FUNGAL PATHOGEN CAUSINGMANGO ANTHRACNOSEIN SENEGAL

Mangois a major crop that represent 63% of fruit production in Senegal. The mango business suffers however from major phytosanitary constraints such as mango anthracnose caused by Colletotrichum gloeosporioides. Fungicides are usually sprayed for the control of this fungal pathogen with their downside of negative impacts on human health and on environment. Fungi of the genus Trichoderma are reported to have great potentialfor biological control on pathogens. Their ability to control C. gloeosporioides was tested through confrontation with three isolates of Trichoderma asperellum(S3M4ZIG, F3GP3 and F3GP3-5), one isolate of Trichoderma viride (F2KV3) anda fifth isolate ofTrichoderma sp. (S5M5ZN). These isolates, obtained from mango tree organs in Senegal,were used in direct confrontation against C. gloeosporioidesin vitro and further onin vivo tests on fruits.The incidence and severity of anthracnose were evaluated after 20 days of incubation.In dual culture in the petri dishes, the isolate S5M5ZN inhibited totally the mycelial growth of C. gloeosporioides,followed by the strains F3GP3 (T. asperellum), F3GP3-5 (T. asperellum), F2KV3 (T. viride) and S3M4ZIG (T.asperellum), that caused respective reduction of mycelial growth of the pathogen by 89.41 ± 18.33%, 89.01 ±19.01%, 77.25 ± 19, 77%, 77.25 ± 12.95%.For thein vivotests, the mangoes soaked with distilled water (negative control) and those inoculated with onlyC.gloeosporioides(positive control) hada disease severity of respectively 20.36±4.39% and 50.69±6.58%. The Trichoderma isolateS3M4ZIG, showed the best efficacy on mango with the lowestdisease severity of 5.55±00.00%.