Allelopathic effects of water extracts from stem and leaf of Euphorbia helioscopia on seed germination and seedling growth of three turfgrass species.

The germination rate,germination index,seedling height and root length of F.elata,Trifolium repens and Medicago sativa seeds cultured in filter paper method with water extract from stem and leaf of E.helioscopia were determined to study the comprehensive allelopathic effects of water extract from stem and leaf of E.helioscopia and to develop new plant herbicides with pollution-free.The results showed that water extract from E.helioscopia has the certain effect on tested lawn species.The germination rate,germination index,seedling height and root length of three lawn plant species show a gradual decline trend with increase of water extract compared with CK.The index of relevant allelopathic effect indicates that different indexes are inhibited obviously.Seedling height shows a first rising and then decline trend.The integrated effect(SE value) showed that different lawn species has different sensitive degree to water extract of E.helioscopia,of which,Trifolium repens is most sensitive to water extract of E.helioscopia.The water extract from E.helioscopia with 6.25% concentration promotes the allelopathic effect on F.elata and M.sativa.