Screening Some Medicinal Plant Extracts Against Alternaria Sesami, the Causal Agent of Alternaria Leaf Spot of Sesame

Natural plant extracts / products have the potential as safe alternativesfor chemical fungicides in plant disease management. methanol and puremethanol:water (50:50 v/v) extracts of peppermint, lavandula, eucalyptus,datura and nettle were screened for their antifungal activity against alternariasesami, the causal agent of alternaria leaf spot of sesame at 5, 10 and 15%concentrations in shahrood agricultural research center, shahrood, iran,during 2010. poisoned food technique and spore germination assay were usedto evaluate the antifungal potential of plant extracts against the pathogen.fungicide mancozeb 80wp (0.2%) was used for better comparison. resultsindicated that methanolic extracts of peppermint (15 and 10%), lavandula(15%) and eucalyptus (15%) were more effective than methanol: water extractsand completely inhibited the growth of the pathogen. among tested extracts,methanolic extracts of peppermint (15%) and eucalyptus (15%) were best inpreventing the spore germination of the pathogen (p =0.01).