Bio-efficacy of some Botanicals, Antagonistic fungi, and Fungicides against Fusarium oxysporum f.sp. phaseoli causing Fusarium wilt on common bean plants

Abstract

Wilt of common beans (Phaseolus vulgaris L.) caused by Fusarium oxysporum f.sp. phaseoli, has been found to be important in Menoufia governorate, Egypt. The objective of this study was to evaluate the efficacy of five plant extracts, three Trichoderma isolates, and two systemic fungicides in controlling Fusarium wilt infestations under laboratory and greenhouse conditions. In vitro tests revealed that all of the plant extracts tested exhibited fungicidal activity against F.oxysporum f.sp. phaseoli, albeit to varying degrees of efficacy. Cuminum cyminum and Dianthus caryophyllus aqueous extracts were the most effective against Fusarium. All three Trichoderma isolates inhibited the mycelium growth of the pathogen. Furthermore, the efficacy of two systemic fungicides (Rizolex-T and Topsin M) were investigated and both tested fungicides reported a significant reduction in the growth of the pathogen compared to the control. In vivo evaluation the results showed that all tested agents were effective in reducing wilt incidence (pre-and post-emergence, survival of plants, and severity of infection) and increasing some vegetative growth parameters of bean plants (plant height, number of branches, and number of leaves/plants) compared to the infected control. In comparison to synthetic fungicides, our study demonstrated that the use of aqueous plant extracts could be an applicable, safe, and costeffective method for controlling F. oxysporum f.sp. phaseoli. In addition, our study found that local isolates of T.harzianum, T. asperellum, and T.viride have the potential to be used as biological control agents against F. oxysporum f.sp. phaseoli.