Distribution, Frequency, and Population Density of Nematodes in West Virginia Peach Orchards


  • James B. Kotcon


Nematode population densities were determined in soil and root samples collected from 205 peach (Prunus persica L.) orchard blocks between 25 March and 5 May 1986. Representative specimens from 75 blocks were identified to species; 28 species of plant-parasitic nematodes were identified. Predaceous nematodes (Mononchidae) were observed in 71% of the samples. The most common plant-parasitic genera were Paratylenchus, Helicotylenchus, Pratylenchus, and Xiphinema, occurring in 85, 84, 77, and 74% of the samples, respectively. Population densities of Xiphinema, Pratylenchus, Meloidogyne, Hoplolaimus, and Criconemella were at potentially damaging levels in 74, 19, 13, 10, and 2% of the samples, respectively. Potentially damaging nematode densities were observed in 78% of orchard blocks surveyed, with 35% having two or more nematodes with densities high enough to warrant concern. Nematode densities differed among soil types and tree rootstocks and were correlated with tree mortality rates. Key words: Criconemella, Helicotylenchus, Hoplolaimus, Meloidogyne, distribution, peach, Pratylenchus, predaceous nematode, Prunus persica, soil texture, survey, Xiphinema.