Cause Several virus diseases have been reported on cranberry. A strain of the blueberry red ringspot virus, a caulimovirus, has been associated with symptoms of cranberry ringspot. Although tobacco streak virus (TSV) has been reported to occur in symptomless cultivars, fruit scarring and reduced berry weight and fruit set have been associated with this virus in cranberry. Plants, however, recover from these symptoms the following year. The carlavirus blueberry scorch virus (BlScV) has been described from symptomless cranberry plants.
Uprights infected with blueberry shock virus (BlShV) also produced scarred, disfigured berries that turn red prematurely. Plants have also been shown to recover the next year from blueberry shock virus symptoms and yield. The virus from blueberry appears to be different than the virus found in cranberry. This virus can be transmitted by seed or by propagation from infected plants.
Symptoms
BuRRV - Light greenish-yellow rings appear on red fruit.
TSV (and BlShV) - Scars appear on berries as necrotic, irregularly shaped, and indented lesions ranging up to half an inch long. Affected berries turn red prematurely. Some berries abort while others matured but were distorted with lesions causing deep indentations and/or cracks. Other parts of the plant seem normal. Plants do not show symptoms the following year.
Cultural control
- For all viruses, use virus-tested (and found to be free of all known viruses) certified stock.
Let tobacco streak virus run its course. Plants that have recovered appear to produce a full crop, but these plants can continue to serve as an inoculum source for nearby plants and for any new plantings.
References Polashock, J.J., Ehlenfeldt, M.K., and Crouch, J.A. 2009. Molecular detection and discrimination of blueberry red ringspot virus strains causing disease in cultivated blueberry and cranberry. Plant Disease 93:727-733.
Thomas-Sharma, S., Wells-Hansen, L., Page, R., Kartanos, V., Saalau-Rojas, E., Lockhart, B.E., and McManus, P.S. 2018. Characterization of blueberry shock virus, an emerging Ilarvirus in cranberry. Plant Disease 102:91-97.
Wegener, L.A., Punja, Z.K., and Martin, R.R. 2004. First report of blueberry scorch virus in cranberry in Canada and the United States. Plant Disease 88:427.
Wells-Hansen, L.D., and McManus, P.S. 2016. Recovery of cranberry plants infected with tobacco streak virus and incidence and distribution of TSV in the field. Plant Disease Plant Disease 100:2257-2265.