Notes on Raspberry Diseases
Viruses
Identification
Virus diseases cause various symptoms that include leaf curl and pucker
and a yellow-mottled discoloration known as mosaic. Virus infected plants
often produce small crumbly berries and low yields.
Aphids transmit raspberry mosaic and raspberry leaf curl virus from infected
to healthy plantings. Dagger nematodes spread tomato ringspot virus.
Symptoms of virus diseases can be confused with similar symptoms from
other causes. For example, herbicide injury, poor crop nutrition, root
rots or drought cause poor vigour and yellowing or curled leaves. Poor
pollination, plant bug injury or a crop nutrition problem can cause crumbly
berries.
Monitoring
Leaves of virus-infected plants may not always show virus-like symptoms.
Symptoms may appear in the spring and disappear again. The best time to
sample plant tissue for virus disease is in the spring, when plants are
in an active growth stage. The Pest Diagnostic Clinic at the University
of Guelph can diagnose some virus diseases using ELISA test kits.
Diagnosis of virus diseases is difficult and should be considered when
other potential causes of the problems have been ruled out.
Management notes
The following steps help minimize the spread of -viruses:
- Use virus-tested, disease-free planting stock from an accredited plant
propagation program.
- Destroy all nearby wild raspberries and blackberries because these
are frequently infected with virus diseases.
- Set new plantings at least 16 m from older plantings to reduce the
spread of aphids from one planting to another.
- Black and purple raspberries are very susceptible to virus diseases.
To reduce the spread of virus from black and purple varieties to red
raspberries, do not plant red raspberries close to purple and black
raspberries.
- Rogue out and completely destroy all virus-infected plants as soon
as symptoms of mosaic or leaf curl appear.
Table 1. Raspberry Virus Diseases and Their Vectors
|
Virus
|
Symptoms |
Vector |
| Raspberry bushy dwarf |
Leaf mottling, shortened internodes, reduced vigour |
pollen |
Raspberry mosaic
Raspberry leaf curl
|
Leaf mottling, curling, reduced vigour |
large raspberry aphid |
| Raspberry ringspot (tomato ringspot virus) |
Crumbly fruit, yellow leaf mottling, declining vigour |
dagger nematode |
Learn more...
