Identification de l’agent causal du flétrissement vasculaire de l’haricot (Phaseolus vulgaris L.) dans la région de Mostaganem et évaluation de la lutte biologique

Abstract

This study aimed to evaluate in vitro the antagonistic potential of various isolates of the biocontrol agent Trichoderma against the phytopathogen Fusarium oxysporum f. sp. phaseoli, the causal agent of fusarium wilt in common bean (Phaseolus vulgaris L.). The evaluation was conducted using a dual culture confrontation test in Petri dishes to monitor mycelial growth kinetics and calculate percentage inhibition rates over an 8-day incubation period. The results demonstrated a clear variability in inhibitory efficiency among the tested isolates. Isolates T16 and I exhibited the highest decisive inhibitory performance, exceeding 75% inhibition against most pathogenic strains, driven by the mechanism of direct mycoparasitism (mycoparasitisme). In contrast, other isolates showed varied efficacy; specifically, T5 and T13 recorded moderate and limited inhibition rates against strain 3 (Souche 3), while isolate T12 displayed severe inefficiency and a near-total failure in suppressing the growth of strain 5, with a negligible inhibition rate not exceeding 10%.