Host status and damage potential of Paratrichodorus renifer and Pratylenchus penetrans (Nematoda) to blueberry (Vaccinium spp.)

Authors: WALTERS, T - Washington State University; Zasada, Inga; PINKERTON, J - Washington State University; KOCH, C - Agri Food - Canada

Submitted to: Canadian Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/26/2012
Publication Date: 4/2/2012
Citation: Walters, T.A., Zasada, I.A., Pinkerton, J.N., Koch, C. 2012. Host status and damage potential of Paratrichodorus renifer and Pratylenchus penetrans (Nematoda) to blueberry (Vaccinium spp.). Canadian Journal of Plant Pathology. 34(2):277-282.

Interpretive Summary: Plant-parasitic nematodes are microscopic soil worms that cause ten billion dollars in U.S. crop losses annually. Blueberry is a rapidly expanding agricultural sector in the Pacific Northwest region of the United States and Canada. This research was conducted to determine the host status of blueberry varieties to stubby root (Paratrichodorus renifer) and root lesion (Pratylenchus penetrans)nematodes and to assess the impact of these nematode on blueberry establishment and yield. Six blueberry varieties were exposed to nematodes in greenhouse experiments, and most were good hosts for stubby root nematode; the exception was a rabbiteye-type of blueberry which was a poor host to the nematode. None of the tested blueberry varieties were hosts for root lesion nematodes. In field experiments, stubby root nematode reduced canopy development and yield of blueberry over a 3-year period. These results are significant because they will help guide plant-parasitic nematode research efforts by scientists to better serve blueberry growers in the Pacific Northwest region of the United States and Canada.

Technical Abstract: Stubby root nematodes (Paratrichodorus species) and root lesion nematodes (Pratylenchus species) have been associated with blueberry in most blueberry-growing regions of North America. Relatively little is known, however, of the host status and pathogenicity of these nematodes to blueberry. We performed controlled inoculation studies on population growth of Paratrichodorus renifer and Pratylenchus penetrans on a range of blueberry varieties, including representatives of V. corymbosum, V. angustifolium, and V. ashei. Under greenhouse conditions, all tested blueberry varieties were considered good hosts to P. renifer (reproduction factor (RF) values > 1.0) except V. ashei ‘Powderblue’ which was considered a poor host (RF = 0.2 + 0.1). In the same experiment, P. renifer reduced root biomass of susceptible blueberry varieties; however this effect was not consistent across trials. P. penetrans did not reproduce on any blueberry genotypes under greenhouse conditions. In field microplots, P. renifer reduced berry yield, canopy volume, and top dry weights of V. corymbosum x angustifolium ‘Chippewa’ two years after inoculation by 40, 25, and 25%, respectively . Our results clearly indicate that P. renifer population densities increase on V. corymbosum and V. angustifolium and is potentially damaging to blueberry.