Location: Forage Seed and Cereal ResearchTitle: Virus incidence in orchardgrass (Dactylis glomerata L.) seed production fields in the Willamette Valley
|Gilmore, Barbara - Barb|
|Alderman, Stephen - RETIRED ARS EMPLOYEE|
|Martin, Robert - Bob|
|Sullivan, Clare - OREGON STATE UNIVERSITY|
|Anderson, Nicole - OREGON STATE UNIVERSITY|
|Hoffman, George - OREGON STATE UNIVERSITY|
|Guy, Paul - UNIVERSITY OF OTAGO|
Submitted to: Crop, Forage & Turfgrass Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/6/2017
Publication Date: 6/1/2017
Citation: Gilmore, B.S., Martin, R.C., Dombrowski, J.E., Alderman, S.C., Martin, R.R., Mosier, N.J., Sullivan, C.S., Anderson, N.P., Hoffman, G., Guy, P.L. 2017. Virus incidence in orchardgrass (Dactylis glomerata L.) seed production fields in the Willamette Valley. Crop, Forage & Turfgrass Management. doi:10.2134/cftm2016.12.0087.
Interpretive Summary: Orchardgrass seed production fields of Western Oregon were sampled and tested three consecutive years for the presence or absence of three viruses, Barley yellow dwarf virus (BYDV), Cereal yellow dwarf virus (CYDV), and Cocksfoot mottle virus (CfMV). There was a very low incidence of BYDV over the three year testing period in the orchardgrass fields. The CYDV in 2014, occurred in fifty percent of the 18 orchardgrass fields tested. In 2015, the incidence of CYDV exploded and 72% of the 18 fields sampled were infected, with most of those fields having a significant number of positive samples. In 2016 BYDV infection was only found in two of the 24 fields tested. The CfMV was present all three years of the survey in the orchardgrass fields. In 2014, 56% of the fields had infection; in 2015, 72% of the fields were infected; and in 2016, 79% of the fields tested positive. In 2015 and 2016, in the infected orchardgrass fields over 20% of the samples tested positive for CfMV.
Technical Abstract: A survey was conducted over the course of three years (2014-2016) for the presence of Barley yellow dwarf virus (BYDV-MAV and BYDV-PAV), Cereal yellow dwarf virus (CYDV-RPV), and Cocksfoot mottle virus (CfMV) in orchardgrass (Dactylis glomerata) fields in the Willamette Valley, Oregon. There was an extremely low incidence of BYDV-MAV and BYDV-PAV in orchardgrass during this three year period. The CYDV-RPV virus was detected in 50% of the 18 fields in 2014 , and in 72% of the 18 fields tested in 2015. Surprisingly, the incidence dropped to only 8% of the 24 fields sampled in 2016. The number of fields sampled that were infected with CfMV gradually increased from 56% in 2014 to 79% in 2016. The number of infected samples within a field (within field incidence) of CfMV also increased during this time frame, while the incidence of CYDV-RPV-infected orchardgrass fields decreased between 2015 and 2016.