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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Disease and Pest Management Research Unit » Research » Publications at this Location » Publication #410784
Research Project: Disease Management in Small Fruit and Nursery Crops Based on Knowledge of Pathogen Diversity, Biology, and Environmental Effects

Location: Horticultural Crops Disease and Pest Management Research Unit

Title: Host status of ornamental shade trees and shrubs to plant parasitic nematodes

Author
item BENEDETTI, T - Oregon State University
item Weiland, Gerald - Jerry
item Zasada, Inga

Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2024
Publication Date: 6/28/2024
Citation: Benedetti, T., Weiland, J.E., Zasada, I.A. 2024. Host status of ornamental shade trees and shrubs to plant parasitic nematodes. Journal of Nematology. 56(1):10.2478. https://doi.org/10.2478/jofnem-2024-0024.
DOI: https://doi.org/10.2478/jofnem-2024-0024

Interpretive Summary: Plant-parasitic nematodes, microscopic worms that attack plants, are a constraint to the production of ornamental plants, such as trees and shrubs. More information about nematodes impacting ornamental plants is needed to help guide management. This research evaluated the ability of several ornamental trees and shrubs to host plant-parasitic nematodes. The research found that most of the plants were good hosts for nematodes, indicating that these nematodes may need to be managed when found in nurseries. These results will help horticulturalists make decisions regrading the management of plant-parasitic nematodes on ornamental trees and shrubs.

Technical Abstract: Oregon leads the United States in nursery production of shade trees and is third in deciduous and broadleaf evergreen shrub production. Plant-parasitic nematodes have been implicated in problems with the growth of plants in nurseries and are also of phytosanitary risk. A greenhouse experiment was conducted to evaluate the host status of four tree (Quercus alba, Quercus garryana, Acer campestre, Thuja occidentalis) and two shrub (Buxus sempervirens, Rhododendron sp.) species to Meloidogyne incognita, Meloidogyne hapla, and Pratylenchus neglectus. Each plant x nematode treatment was replicated five times and the experiment was conducted twice. Plants were inoculated with 3,000 eggs of M. incognita or M. hapla and 2,500 individuals of P. neglectus two weeks after planting. After three months, the plants were harvested, and the total density of nematodes in soil and roots for P. neglectus and the total density of second-stage juveniles in soil and eggs on roots for M. hapla and M. incognita were determined. The final nematode population (Pf) and reproductive factor (RF = Pf/initial population density) were calculated. For M. incognita and M. hapla, all of the ornamental trees and shrubs would be considered as fair to good hosts with RF values > 1. Meloidogyne incognita had the highest Pf (5,234 total juveniles and eggs/pot) and RF value (28.4) on maple (A. campestre). For P. neglectus, all of the ornamental trees and shrubs were fair to good hosts, except for boxwood. Boxwood was not a host for P. neglectus with an RF value of almost 0. This is the first report of Q. alba, Q. garryana, and A. campestre as hosts for M. incognita, M. hapla, and P. penetrans. This is also the first report of arborvitae and rhododendron as hosts for P. penetrans and the non-host status of boxwood for P. penetrans.