When the orchard is developed, use procedures that improve soil tilth and drainage to help reduce nematode damage. Rootstock Selection . Use certified nematode-free rootstocks. Among peach rootstocks, Nemaguard is known to be resistant to root knot nematodes, but it is susceptible to ring and root lesion nematode. Lovell is a slightly poorer host to ring nematode and somewhat more tolerant of bacterial canker complex but susceptible to root knot and root lesion nematodes.
Some apricot rootstocks are nonhosts for root knot nematode.
Plum rootstocks Myrobalan 29C and Marianna 2624 are resistant to root knot nematode, but highly susceptible to ring and somewhat susceptible to root lesion nematode. Contact your local farm advisor for additional information on rootstock selection. When to Treat . Trees planted on fumigated orchard sites are generally known to have improved growth and yields compared to those on nonfumigated sites. Threshold levels for a postplant treatment have not been established.