Natural Products, Organic Chemistry : Fungicidal Activities of 67 Herb-Derived Oils against Six Phytopathogenic Fungi

The oils from 67 herbs were tested for their fungicidal activities against 6 phytopathogenic fungi in a greenhouse at 10 and 5 mg/pot. The efficacy varied with both the plant pathogen and herb oil species used. The oils of Anthemis nobilis and Rosemarinus officinalis gave over 80% control value (CV) against Pyricularia grisea, and that of Curcuma longa exhibited potent fungicidal activity (CV >90%) against Rhizoctonia solani. In a test with Botrytis cinerea, the oils of Cuminum cyminum and Lavendula augustifolia exhibited strong fungicidal activities. Against Phytophthora infestans, the oil of C. longa showed strong fungicidal activity. The oils of Dioscorea villosa and Vetiveria zizanioides produced strong fungicidal activities against Puccinia recondita, and those of C. longa and Melaleuca viridiflora showed strong activities against Erysiphe graminis. Potent fungicidal activities were produced from the oil of C. cyminum against SSR and SRR, and L. augustifolia against SSR and RSR strains. As a naturally occurring fungicide, these herb-derived oils could be useful as new fungicidal products against phytopathogenic fungi.