In vitro nematicidal activity of aqueous plant extracts on Chilean populations of Xiphinema americanum sensu lato . Nematropica 31:47-54. In a search for alternatives to chemicals in nematode management, the nematicidal activity of 30 plant species (9 native and 21 naturalized in Chile) was tested on a Chilean population of Xiphinema americanum sensu lato , an economically important pathogen in grapevine. Aqueous extracts were tested in a standard concentration (S) at 1:4 W/V of fresh plant material, or 1:20 W/V of air-dried plant parts; and 21 plants, were also tested at 25% of S. Distilled water was used as the control. Nematicidal activity was evaluated by nematode immobility after 24-48 h of immersion in the extracts, followed by 24 h in distilled water. At the standard concentration, all the extracts showed nematicidal or nematostatic activity after 24 h of exposure, but this effect decreased in the dilute treatment of 33% of the extracts, mostly top extracts. Nematode immobilit
