Allelopathic and Antioxidant Activities of Extracts and Residues from Persimmon (Diospyros kaki Thunb.) Leaves

Aqueous leaf extracts and residues from sweet (cv. “Booyu”) and puckery persimmon (cv. “Daebong”) cultivars were bioassayed against alfalfa (Medicago sativa) or barnyardgrass (Echinochloa crus-galli) seedlings to determine their allelopathic effects. A significant inhibition on alfalfa root growth were observed with increasing of treated concentration or amount. Root growth was more inhibitory to the aqueous extracts than hypocotyl growth did. Incorporation of leaf dry matters of persimmon into a synthetic soil significantly reduced seedling growth of barnyardgrass. Antioxidant activities measured by Rancimat method, TBA (2-thiobarbituric acid) method and DPPH (1,1-diphenyl- 2-picryl hydrazyl) radical scavenging activity for the ground samples or methanol extracts in ‘Booyu' were greater than in “Daebong”, although those were less than those of ascorbic acid and BHT. These results suggest that persimmon leaves had allelopathic potential as well as antioxidant activity, and their activities were differently exhibited depending on cultivar