Abstract:
The present study was undertaken to assess the allelopathic effect of Echinochloa colona L. and Cyperus iria L. in relation to the
germination and primary growth of Oryza sativa L. (rice) and Glycine max L. (soyabean). Effects of dichloromethane (DCM) and
double distilled water soluble (DDW) fractions of E. colona L. and C. iria L. root and aerial part extracts reduced germination
and suppressed early seedling growth of rice and soyabean.With increase in extract concentration from 1 to 100mg/mL, a gradual
decrease in seed germination and seedling length occurred.The highest growth of G. max seedling was recorded in DDWfraction
of E. colona aerial part extract at 1mg/mL concentration with 94% germination and the lowest length was found in DCM fraction
of C. iria root extract at 100mg/mL concentration with 65% germination. In O. sativa, the highest length was noted at 1mg/mL
concentration in DDW fraction of E. colona aerial part extract with 82% germination and the lowest length was found in DCM
fraction of C. iria and E. colona root extracts with germination 57% and 62%, respectively, at 100mg/mL concentration. The results
suggested that these weeds had good allelopathic potential which reduces germination and plant growth.
