Erica Pate & Katie Goldenhar
In 2016 & 2017 OMAFRA conducted initial raspberry virus surveys to determine which viruses were present in the province. At least one virus was detected in 90% of the samples collected. Rubus yellow net virus (RYNV) was the most common, followed by Blackberry chlorotic ringspot virus (BCRV). At least one virus was detected in 73% of all the samples we collected, and 6% of the samples had more than one virus present.
A follow-up survey was conducted in 2023 to determine the frequency and incidence of raspberry viruses 6 years later. 96 samples were collected from 16 farms across Ontario. Samples were tested for the following viruses:
- Tomato Ringspot Virus (ToRSV)
- Raspberry Bushy Dwarf Virus (RBDV)
- Tobacco Streak Virus (TSV)
- Blackberry Chlorotic Ringspot Virus (BCRV)
- Blackberry Yellow Vein Associated Virus (BYVaV)
- Black Raspberry Necrosis Virus (BRNV)
- Raspberry Leaf Mottle Virus (RLMV)
- Rubus Yellow Net Virus (RYNV)
Five viruses were identified in fields across Ontario (Table 1). Rubus yellow net virus (RYNV) was the most common and was identified in 91% of samples (Fig 1). All viruses except RYNV decreased in incidence since the 2017 survey. Tobacco streak virus, black raspberry necrosis virus, and blackberry yellow vein associated virus were not identified in any samples, consistent with the 2017 survey.
Virus | Vector | Symptoms |
Rubus Yellow Net Virus (RYNV) | Aphid | Either no symptoms or faint vein netting/vein chlorosis, slightly cupped leaves. |
Raspberry Bushy Dwarf Virus (RBDV) | Pollen, Seed | Crumbly fruit, druplet abortion, dwarfing, interveinal chlorosis. |
Blackberry Chlorotic Ringspot Virus (BCRV) | Pollen, Seed | Line patterns and ringspots on leaves, wilting. Maybe asymptomatic |
Tomato Ringspot Virus (ToRSV) | Nematode | Leaf mottling, pale ringspots on leaves, distortion of leaves, weakened plants, crumbly fruit. |
Raspberry Leaf Mottle Virus (RLMV) | Aphid | Raspberry decline and crumbly fruit, leaf mottling and distortion, stunting. |
At least one virus was detected in 95% of all samples we collected, and 25% had more than one virus present (Fig 2).
Single plant infections of certain viruses in some varieties do not necessarily cause visual symptoms or economic losses, such as RBDV, however in other varieties a single infection can result in both symptoms and economic loss. Plants with more than one virus often show symptoms and result in economic loss.
As the incidence of samples with more than one virus has increased over the years managing viruses and vectors is important. There are a number of management options that will mitigate the effects of viruses in raspberries:
- Begin with clean planting stock
- Destroy wild raspberries and blackberries
- Spread out plantings to reduce the spread of vectors
- Manage aphids
- Separate red, black and purple raspberries. Black and purple raspberries are more susceptible to some viruses.
- Destroying plantings with confirmed virus symptoms can help reduce risk.
If you suspect viruses are impacting the yield and vigour of your fields send samples to a diagnostic lab.
Thank you to the participating growers. This project was funded through the Sustainable Canadian Agriculture Partnership Plant Health Project.
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