Abstract

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 immobility was observed at 25% of S, after 24 h, with plant extracts in 18 out of 21 plant species including: Tagetes erecta, T. patula nana and Zinnia elegans (tops and roots); Asparagus officinalis, Brassica campestris, Calendula officinalis Melissa officinalis, Plantago major, Ruta graveolens (roots); Thymus serpyllum (leaves); and the native Chilean plants Aristotelia chilensis (leaves); Cestrum parqui (bark); Oenothera affinis, Oxalis rosea, Stachys albicaulis (whole plants); Quillaja saponaria (leaves and flowers); and Vestia lycioides (top). After 48 h of exposure, nematode immobility was observed at 25% of S in Chenopodium ambrosioides (top and root) and M. officinalis (top). These results confirm earlier reports on nematicidal properties of the 30 plant species tested. Some of these plants could have practical application in the management of Xiphinema in vineyards.