Antagonistic activity of some bioagents against root rot diseases of pepper (Capsicum annum L.)

Eight isolates of bioagents (fungal and bacterial), obtained from the rhizosphere of healthy pepper plants collected from various pepper-growing sites in Kafr El-Sheikh governorate, were tested against pepper root-rot pathogens including Pythium aphanidermatum, Fusarium solani, F. oxysporum, F. moniliformis and Macrophomina phaseolina. In in vitro study, the fungal bioagents (Trichoderma viride (TV1 and TV2) and T. harzianum (TH1 and TH2) exhibited the maximum antifungal activity against the five phytopathogens compared to the bacterial bioagents (Pseudomonas fluorescens (P1 and P2) and Bacillus subtilis (B1 and B2). In pots experiment, TV1 and P2 bioagents caused the least disease severity among all treatments. All bioagents were effective with different degrees specially Trichoderma spp. to promote the growth parameters of pepper plants and manage root rot disease that caused by different pathogens. Furthermore, they had equal efficacy with fungicide treatment under in vitro and in pots experiment. Thus, application of biological methods in plant disease control is an effective alternative technique and could have a potential biofertilizer effect, since they stimulated the growth of pepper plants.