Prospecting for Nematodes Associated With Different Prunus Rootstocks in Brazil

The aim of the present study was to carry out a search for phytonematodes to verify the abundance and frequency of nematodes present in a peach orchard at eight years of age. Soil and root samples from nine peach rootstocks were collected in an experimental area in the district of Capão do Leão, in the State of Rio Grande do Sul, Brazil. After extraction, the samples were evaluated under an optical microscope. Nematodes of the following genera were identified in the samples- Meloidogyne spp., Pratylenchus spp., Helicotylenchus spp., Mesocriconema spp., Trichodorus spp., Longydorus spp., Tylenchorchynchus spp., Hemiciclyophora spp., Xiphinema spp., Tylenchulus spp., Dorylaimus spp., Rotylenchulus spp. and Mononchus spp., all associated with the roots or soil rhizosphere of ‘Aldrighi’, ‘Capdeboscq’, ‘Flordaguard’, ‘Nemaguard’, ‘Okinawa’, ‘Tusukuba’, ‘Umezeiro’, ‘Viamão’ and ‘Industry’ rootstocks. The most frequent phytoparasitic nematodes were Meloidogyne spp., and Mesocriconema spp., which, under high populations or under inadequate management of the cultivated area, represent a risk to peach cultivation. Xiphinema and Pratylenchus are two other phytonematodes that can cause damage to peach trees and were identified in greater abundance in the ‘Industry’, ‘Viamão’ and ‘Nemaguard’ rootstocks. Under the conditions of the present research the ‘Okinawa’ and ‘Umezeiro’ rootstocks proved to be unfavourable hosts, especially for Meloidogyne spp. and Mesocriconema spp. The ‘Viamão’, ‘Capdeboscq’, ‘Aldrighi’ and particularly the ‘Industry’ rootstcks should not be recommended for use in areas with an incidence of the nematodes Meloidogyne spp. or Mesocriconema spp.