Effect of plant extracts and organic emulsifiers on control of anthracnose in persimmon

Abstract

The objective of this research was to determine suppression rate of anthracnose (Colletotrichum coccodes) in persimmon by using plant extracts from different extraction methods (water, boiling water, fermentation, and ethanol) from various plant parts (leaves, stems, fruits, and roots) in 47 species from 27 families. Suppression rate of C. coccodes was also studied by using mixers of various plant extracts and organic emulsifiers. Finally, the controlling effect on C. coccodes and leaf injury in persimmon trees was determined by using selected plant extracts and organic emulsifiers. Fermentation extracts of Torilis japonica roots and Portulaca oleracea above ground parts, ethanol extracts of Rheum palmatum roots, and Cinnamomum cassia barks among 47 plant species from 27 families were more effective on suppression rate of anthracnose, which was >83% suppressed by 10% of the plant extracts in the laboratory test. Anthracnose was 100% suppressed by 3% brown rice vinegar, 3% powder soap, 5% loess sulfur, and 5% natural emulsifier-B in a laboratory test. Synergistic effects on suppression rate of anthracnose by combination applications of plant extracts and organic emulsifiers did not appear. In the treatment of plant extracts alone, anthracnose was 63% and 51% reduced by 5% fermentation extract of Torilis japonica and 5% ethanol extract of Rheum palmatum compared with non-treated control, respectively in an organically produced persimmon plants. However, in combination treatments of plant extracts and organic emulsifiers, anthracnose was 79.2%, 67.3%, 62.7% and 55.7% reduced by 5% fermentation extract of Torilis japonica + natural emulsifier-B (1%), 5% fermentation extract of Torilis japonica + loess sulfur (1%), 5% ethanol extract of Rheum palmatum + natural emulsifier-B (1%), and 5% ethanol extract of Rheum palmatum + loess sulfur (1%) compared to non-treated control, respectively, in an organically produced persimmon plants. Persimmon leaf injuries did not show by treatments of 10% fermentation extract of Torilis japonica, 10% ethanol extract of Rheum palmatum, 5% natural emulsifier-B and 5% loess sulfur. Thus, the plant extracts and organic emulsifiers may be used for controlling anthracnose in organically produced crop fields.