Fungicidal Activity of Aqueous Leaf Extract on Alternaria brassicae

Alternaria brassicae is a widespread pathogen causing black leaf spot in the common cabbage (Brassica oleracea Linn.). Ample spectrum of effective chemical fungicides is in use against this pathogen. The agricultural areas of the Nilgiris are fragmented shola forests of this biodiversity hot spot. The indiscriminate usage of chemical fungicides may cause physiological damage, including the endocrine disruption not only in the human but in wild life also. So a universally available bio-fungicide is in quest. With this view the study was conducted to find a biofungicide against the common crucifer pathogen Alternaria brassica. The experiment tested 10 plant extracts against the pathogen in culture plates. The pathogen is collected from the field and the pure line was isolated, the pathogenesis was confirmed by re-infecting the pathogen on host under controlled condition. The majority of the extracts though show efficient in controlling the pathogen, Solanum nigrum is more effective and the activity is almost found equal to chemical fungicides. The results were discussed in relation to the literature and steroidal saponins were concluded to be the active principle in controlling the pathogen.