EVALUATION OF FIVE NEMATODE-ANTAGONISTIC PLANTS USED AS GREEN MANURE TO CONTROL XIPHINEMA INDEX THORNE ET ALLEN ON VITIS VINIFERA L.
Keywords: allelopathy, brassica juncea, brassica napus, chenopodium ambrosioides, fenamiphos, grapevine, grapevine fan leaf virus (gflv), nematicidal plants, ruta graveolens, thymus vulgaris
AbstractThe ectoparasitic nematode Xiphinema index is economically important on grapevine (Vitis vinifera L.) in Chile, as a root parasite as well as a vector of Grapevine Fan Leaf Virus (GFLV). The objective of this study was to evaluate the effect of five nematode-antagonistic plants incorporated as green manure in greenhouse pot cultures on X. index maintained on grapevine, cv. Thompson Seedless. The antagonistic plants were: rapeseed (Brassica napus L. cv. Rangi), wormseed (Chenopodium ambrosioides L.); rue (Ruta graveolens L.), brown mustard (Brassica juncea Czern. & Coss. cv. Nemfix) and thyme (Thymus vulgaris L.). Their effects were compared with the following four treatments: barley (Hordeum vulgare L.); fenamiphos at 0.04%; grapevine plants inoculated with X. index as control; and grapevine with no further treatment. The incorporation of B. juncea cv. Nemfix reduced the nematode population by nearly 65% compared to the more than an 80% reduction with fenamiphos, with both treatments significantly different from all other treatments. The fenamiphos treatment resulted in the lowest root damage but caused a significant reduction of the total fresh weight of the grapevine plants, possibly due to phitotoxicity. At the rates of incorporation (2% W/V), brown mustard, thyme, wormseed and rue appeared to be well suited as potential green manure crops for control of X. index in grapevine.