Assessment of the distribution of dagger nematodes and associated nematode transmitted viruses in Pacific Northwest small fruit crops

Authors: OLAYA, C - Orise Fellow; Reinhold Aboosaie, Lauri; PLATT, M - Oregon State University; Peetz, Amy; Donahue, Kelly; Zasada, Inga

Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2024
Publication Date: 6/12/2024
Citation: Olaya, C., Reinhold Aboosaie, L.A., Platt, M., Peetz, A.B., Donahue, K.M., Zasada, I.A. 2024. Assessment of the distribution of dagger nematodes and associated nematode transmitted viruses in Pacific Northwest small fruit crops. Plant Health Progress. https://doi.org/10.1094/PHP-04-24-0034-RS.
DOI: https://doi.org/10.1094/PHP-04-24-0034-RS

Interpretive Summary: Plant-parasitic nematodes, microscopic worms that attack plants and can transmit viruses to raspberry, blueberry and grape plants. When both of these pests are present, the impact on plant production can be significant. This research was conducted to provide an up-to-date assessment of the occurrence and distribution of nematodes and viruses in small fruit production fields in the Pacific Northwest of the U.S. It was found that while the nematode is widespread in the region, virus is not. Out of almost 100 surveyed fields, both pests were only present in less than 5% of fields. These results are encouraging because the disease complex is not widespread in the region. This information will be used by those involved in small fruit production to limit the spread and introduction of this disease complex in the region.

Technical Abstract: Small fruit production is an important component of the agricultural sector in the Pacific Northwest of the United States (Oregon and Washington). A diversity of small fruits is produced in the region including wine grape, blueberry, strawberry, and caneberry (red raspberry, black raspberry, and blackberry). Plant-parasitic nematodes and viruses both impact the production of small fruits in the region; there is not an up-to-date understanding of the distribution of potential virus-vectoring dagger nematodes (Xiphinema spp.) and associated nematode-transmitted polyhedral (nepo) viruses. Soil and plant samples were collected from 43 wine grape vineyards and 24 blueberry, 23 caneberry, 5 strawberry and one currant field(s) in 2021 and 2023. The samples were analyzed to determine the presence of dagger nematodes and the nepoviruses tomato ringspot virus (ToRSV), and tobacco ringspot virus (TRSV). Dagger nematode was found in 52% of sites. The nematode had the highest level of prevalence in wine grape vineyards, followed by raspberry and blueberry fields, compared to the other small fruits. ToRSV was detected in two blueberry fields in Washington. In Oregon, one field each of blueberry, red raspberry and currant and one wine grape vineyard were positive for ToRSV. TRSV was not conclusively found in any of the survey samples. To the best of our knowledge, this is the first time ToRSV is reported in wine grapes in Oregon and in the species of red currant, Ribes spicatum. This study provides an up-to-date assessment of the distribution of dagger nematodes and nepoviruses associated with small fruits in the Pacific Northwest. This information will be used on a regional scale to limit the spread and introduction of this disease complex into small fruit production fields.