|Tzanetakis, I - OREGON STATE UNIVERSITY|
|Barnes, J - OREGON STATE UNIVERSITY|
|Barrett, S - OREGON STATE UNIVERSITY|
|Bolda, M - UC DAVIS|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 5, 2006
Publication Date: October 1, 2006
Citation: Tzanetakis, I.E., Wintermantel, W.M., Cortez, A.A., Barnes, J.E., Barrett, S.M., Bolda, M.P., Martin, R.R. 2006. Epidemiology Of Strawberry Pallidosis Associated Virus And Occurrence Of Pallidosis Disease In North America. Plant Disease. 90(10):1343-1352. Interpretive Summary: In 2002 and 2003, there was a significant decline problem in strawberries in California with losses approaching $30 million in 2003. In an effort to identify the causal agents of the disease, declining plants were tested for eight viruses, two suspected to be whitefly transmitted, four aphid transmitted and two pollen-borne. Strawberry pallidosis was shown to be transmitted by the greenhouse whitefly. In areas with high whitefly populations, infection rates of whitefly transmitted viruses were as high as 90%. Declining plants had a combination of whitefly and aphid transmitted viruses in California. In the Pacific Northwest, declining plants were infected with aphid transmitted viruses and the whitefly transmitted viruses were rare, as were whiteflies. Declining plants had at least three viruses, and, in some cases, as many seven viruses were identified in individual plants. Awareness of the vectors and improved control in the nurseries and, when necessary, in production fields has resulted in the near absence of decline symptoms since 2003.
Technical Abstract: Strawberry pallidosis associated virus was found to be closely associated with pallidosis disease. The modes of transmission of the virus were studied, including pollen, seed (achene) and whitefly transmission. Three whitefly species were tested for their ability to transmit SPaV, but only the greenhouse whitefly, Trialeurodes vaporariorum, was identified as a vector of the virus. Testing strawberries for Strawberry pallidosis associated virus and Beet pseudo yellows virus, a second crinivirus associated with pallidosis disease in strawberry producing areas in North America, confirmed a high incidence of both viruses in areas where high populations of whiteflies were present. Infection rates as high as 90% were observed when plants exhibiting decline symptoms were tested. Lower rates of infection were found in regions where whiteflies were absent or found in low numbers. The role of these criniviruses in the strawberry decline observed over past few years along the western coast of North America was examined.