Allelopathic activities of Jasminum officinale f. var. grandiflorum (Linn.) Kob.: Inhibition effects on germination, seed imbibition, and α-amylase activity induction of Echinochloa crus-galli (L.) Beauv

A methanolic extract in wettable powder from the leaves of Jasminum officinale f. var. grandiflorum (Linn.) Kob. (JWP) was inhibitory to germination and seedling growth of Echinochloa crus-galli (L.) Beauv. weeds. The inhibition percentages on E. crus-galli seed germination treated with 500 to 8,000 ppm for 7 days was about 0 to 70%, respectively, whereas shoot length was inhibited from 19.04 to 71.82% and root length was 76.31 to 100% inhibition, respectively. The imbibition and α-amylase activities in the treated E. crus-galli seeds were progressively depressed with increasing JWP concentrations. The obtained results suggest that JWP inhibited imbibition and α-amylase activity in E. crus-galli seeds during germination. Keywords: Allelopathy, α-amylase, Echinochloa crus-galli, Jasminum officinale, seed imbibition