Allelopathic effect of aqueous extract from alfalfa leaf on test weeds

Alfalfa(Medicago sativa) is one of perennial leguminous pastures;also,one of typical allelopathic plants.Its leaves contain abundant allelochemicals such as saponins,which can suppress some weeds selectively.In this study, the inhibitory potential of aqueous extract from alfalfa leaves against of germination of test weeds was assessed by bioassay.The results showed that the degree of weeds suppression was dependent on extract conditions,including extract concentration,incubation temperature and time,and weed species.Among of them,the combination of 0.45g/ml,24h and 50℃ was the best treatment for weed suppression.Under different treatments,the percentage inhibition of germination was arranged in order by Chenopodium album L. Amaranthus retroflexus L. Digitaria sanguinalis L. Setaria faberii Herrm. Abutilon theophrasti Medic.,which indicated Abutilon theophrasti Medic was more tolerant or resistant than others.