假臭草对南方几种常见大田杂草的化感作用

以假臭草为化感物质供体,飞机草(Eupatorium odoratum L.)、巴西含羞草(Mimosa pudica L.)、稗草(Echinochloa crusgalli(L.)Beauv)、三叶鬼针草(Bidens pilosa L.)和茴麻(Abutilon theophrasti Medic)为受体做生测实验,研究入侵杂草假臭草的鲜样浸提液与干样浸提液的化感作用,为假臭草的绿肥化利用与入侵风险预测提供理论依据。研究结果表明,无论是假臭草鲜样浸提液还是干样浸提液均对供试的几种杂草有明显的抑制作用,并且对幼苗根的抑制作用大于对种子的。在5种供试杂草中,巴西含羞草对假臭草的化感作用耐性最强,飞机草次之。但几种杂草在较高浓度下根全部受到抑制,不能生长。鲜样和干样浸提液强度有一定的差异,但差异不大。因此,将假臭草作为绿肥来防治农田杂草有一定前途,但针对不同的作物系统与主要杂草种类要有广泛的化感研究基础。

Allelopathy of Eupatorium catarium Veldkamp to several weeds common in south China cropping system

Eupatorium catarium Veldkamp, an agressive plant, has spread througout the agroecosytem and wilderness in Hainan and Guangdong province in the last decade and has become a serious problem in many parts of this area. Preliminary research on the Allelopathy of this species found that the aquous extract has strong inhibition to the seed germination and seedling elongation of cabbage and radish. In present study the allelopathy of this species to five conmon weeds (E. odoratum L., Mimosa pudica L., Echinochloa crusgalli (L.) Beauv, Bidens pilosa L. and Abutilon theophrasti Medic) in south China was investigated to further understand its allelochemical potential and the potential used as green manure in cropping system weeds management. Two kinds of aquous extracts, one from fresh matieral and another from dried material, were compared. The result indicated that two kinds of extracts both have strong inhibite effect on five weeds. The roots of five species all showed more sensitive to the extracts than seeds. Under higher extracts density, the roots were inhibited completely. For different species, M. pudica had strongest endurance to the extracts, E. odoratum followed it. There was no siginificant disciplinary differences between two extracts. The results suggested that E. catarium has the potential to be used as green manure in cropping system weeds management, but enough researches need to be conducted to well use it in different systems.