Effect of plant extracts Ammi and Rheum on plant pathogenic fungus Helminthosporium sp

Abstract

Penicillium, Aspergillus, Rhizopus, Altrnaria, and Helminthosporium, were genera of fungi that isolated and identified from local black Barley Hordeum vulgare were obtained from local market of Erbil city. The percentage of infection were 14 ,16 ,8 ,9 ,and 20 % respectively ,the fungus Helminthosporium sp showed highest infection so it was chosen to control it by plant extracts. Flower part of Pick tooth plant Ammi visinaga and root part of plant Rhubarb Rheum ribes two plants which have been used for this study. The chemical compounds that isolated from both plants were phenolic compounds, alkaloids, and tannins. Anti-fungal activity of plant extracts was tested at concentrations 0.01 and 0.04 g/100ml of medium against pathogenic fungus. The results showed that phenolic compounds and alkaloids at 0.01 and 0.04 g/dl of the medium for both plants, exhibited maximum inhibition of mycelium growth, and significantly decreased the dry and fresh weight of culture and spores germination compare with control treatment, while the tannins appeared less activity against mycelium (dry and fresh weight) and also spores germination when compared with other substances.