Distribution of Plant–parasitic Nematodes in Missouri and Arkansas, USA, Vineyards

A nematode survey was conducted from 30 vineyards in Missouri and Arkansas (USA) comprising 107 samples among 21 grape cultivars ( Vitis aestivalis , Vitis labruscana , Vitis vinifera , Vitis hybrids, and Muscadinia rotundifolia ). All the samples tested positive for nematode presence. Eleven different nematode taxa were isolated and identified, five of which have economic importance to grapevines: Xiphinema americanum , Meloidogyne spp., Pratylenchus spp., Criconemoides spp., and Tylenchulus spp. Xiphinema americanum was detected at all but two sites, with 58% of sites having populations at or above levels with expected biological and economic impact. This is primarily a concern because of the ability of X. americanum to transmit Tomato ringspot virus and other viruses. The other four nematode taxa of concern were present in fewer samples and at much lower population densities. Xiphinema index, known to vector Grapevine fanleaf virus was not identified in any of the samples collected.