Susceptibility of Japanese Boxwood, Dwarf Gardenia, Compacta (Japanese) Holly, Spiny Greek and Blue Rug Junipers, and Nandina to Four Nematode Species. D. M. Benson, Associate Professor, Department of Plant Pathology, North Carolina State University, Raleigh 27650. K. R. Barker, Professor, Department of Plant Pathology, North Carolina State University, Raleigh 27650. Plant Dis. 66:1176-1179. Accepted for publication 26 April 1982. Copyright 1982 American Phytopathological Society. DOI: 10.1094/PD-66-1176.

Microplots were used to study the susceptibility of Japanese boxwood, dwarf gardenia, Compacta (Japanese) holly, Spiny Greek and Blue Rug junipers, and nandina to Criconemella xenoplax, Meloidogyne arenaria, Pratylenchus vulnus, and Tylenchorhynchus claytoni over 29 mo. M. arenaria caused severe stunting of dwarf gardenia and Compacta holly. Root galling was heavy on these plants as well as on Japanese boxwood, where stunting was not significant. M. arenaria did not reproduce on the other ornamentals. P. vulnus stunted Japanese boxwood and both junipers, but only Blue Rug juniper developed necrotic foliar symptoms. Nematode densities were greater in May than in October for P. vulnus on the junipers. M. arenaria eggs and P. vulnus juveniles were found in greater numbers in roots than in soil on susceptible hosts. Xylem potentials were higher in P. vulnus-infected junipers than in control plants during drought periods but not during wet periods. Nandina was tolerant to T. claytoni and a nonhost to the other nematode species tested.

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