Sour Cherry Yellows
Prune dwarf
36 host plants
Last updated
This profile contains verified disease data from extension databases. Regional field notes and expert review are in progress.
You'll see green and yellow mottled leaves with green coloring along veins on sour cherry rootstocks (Prunus cerasifera), followed by premature leaf drop and reduced fruiting spurs. Prune dwarf virus spreads through budding, grafting, and infected pollen. Use virus-tested nursery stock and establish new plantings away from old orchards. Roguing mature orchards is uneconomical; thermotherapy can eliminate the virus in propagation material.
Use nursery stock that has been tested and found to be free of all known viruses. If propagating your own trees, use both virus-indexed budwood and virus-certified rootstock.
Quick Reference
Management
Trees are vulnerable to infection throughout their productive life, with enhanced symptom expression in mature, fruiting trees. Newly grafted trees are vulnerable to graft transmission of the virus. Sour cherry cultivars show greater vulnerability to systemic spread and symptom development compared to sweet cherry. Vulnerability increases when soil and nutritional stress compound virus stress.
Initial leaf yellowing may appear the first year of infection, but typically symptoms develop after several years. Symptom expression is most favorable 2 weeks after night temperatures of 50-60°F and day temperatures of 86-95°F. Affected foliage shows a green and yellow mottle pattern with green coloration along the midrib and larger veins. Affected leaves drop prematurely, with subsequent waves of leaf drop occurring. Eventually 30-50% of leaves may drop. Fruiting spurs are reduced, creating a willowy growth habit with long bare branches. Yield quality remains high but quantity may be reduced 50%. Trees decline rapidly when sour cherry yellows is combined with Prunus necrotic ringspot virus.
Cultural Controls
- Use virus-tested (and found to be free of all known viruses) budwood and nursery stock. Propagate only from virus-free mother trees. Establish new sour cherry plantings at distance from older orchards infected with sour cherry yellows. In young, newly infected orchards, rogue infected trees if they are few and detected early. In mature, extensively infected orchards, avoid extensive roguing. Apply gibberellic acid to manage tree vigor and reduce decline symptoms. Avoid planting sour cherry orchards near locations known to have Prunus necrotic ringspot virus, as mixed infections accelerate decline. Source: PNW Plant Disease Management Handbook