Study of the antagonistic activity of Trichoderma asperellum against Fusarium oxysporum and F. solani of Cucurbitaceae in arid regions of Algeria

Abstract This study aims to evaluate the antagonistic activity of Trichoderma asperellum , a strain isolated from the rhizosphere of Biskra region in Algeria, against the pathogenic fungi Fusarium oxysporum and Fusarium solani , which cause significant damage to Cucurbitaceae crops. The aim is to suggest an alternative solution to synthetic phytosanitary products to protect agroecosystems in arid regions. Results showed that T. asperellum recorded significant antagonistic activity towards both pathogens, with inhibition rates of up to 54.12% against F. oxysporum and 56.36% against F. solani when using the direct confrontation method. For indirect confrontation, inhibition rates were 40.6% and 58.22% respectively. In contrast, the fungicide Uniform (Mefenoxam124 g/L + Azoxystrobin 322 g/L) showed less inhibitory activity, with inhibition rates of 32.4% against F. oxysporum and 32.8% against F. solani . The use of T. asperellum as a biological control agent could contribute to a reduction in the use of conventional pesticides, thereby limiting their harmful impact on the environment, human health and biodiversity. These results highlight the potential of T. asperellum as a sustainable and environmentally friendly alternative against these two major plant pathogenic fungi.