Cherry leaf roll disease Identification National Clean Plant

Cherry leaf roll disease Identification National Clean Plant Network – Fruit Trees

Cherry leaf roll identification Background Information • Infection of sweet cherry trees by Cherry leaf roll virus alone is difficult to recognize • Although the virus has a definite impact on production, the symptoms are vague and difficult to distinguish from other forms of stress or disease National Clean Plant Network- Fruit Trees

Cherry leaf virus alone Symptoms • Abundant, small fruit • Late ripening – 3 -14 day delay reaching maturity – Longer delays in years with cool springs • Early leaf senescence – 2 -3 weeks pre-harvest National Clean Plant Network- Fruit Trees

CLRV interacts with other common viruses Background Information • Prune dwarf virus and Prunus necrotic ringspot virus are common in all cherry production areas of the world Cherries with Prunus necrotic ringspot symptoms • Although they can reduce yield, the industry has learned to live with the effects. National Clean Plant Network- Fruit Trees

CLRV interacts with other common viruses Background Information • Most orchards will be infected by one or both viruses by the time they are 12 -14 years old Cherries with Prunus necrotic ringspot symptoms • Cherry leaf roll virus in combination with one of these viruses leads to the development of distinct, more easily recognizable symptoms National Clean Plant Network- Fruit Trees

CLRV & Prune dwarf disease • Delayed or weak bloom on diseased limbs • Leaves emerge & remain in tight whorls for 3 -4 weeks after healthy leaves are fully expanded and laying flat Healthy Cherry leaf roll & Prune dwarf disease National Clean Plant Network- Fruit Trees

CLRV & Prunus necrotic ringspot • Weak terminal growth Diseased Healthy • Delayed fruit development • Poor leaf color & size Cherry leaf roll virus & Prunus necrotic ringspot virus National Clean Plant Network- Fruit Trees

CLRV & Prunus necrotic ringspot • Symptoms resemble Bacterial canker with bud blast & dieback on 1 or 2 major scoffold limbs Cherry leaf roll virus & Prunus necrotic ringspot virus • Gumming is often found at the base of the diseased limb National Clean Plant Network- Fruit Trees

CLRV & Prunus necrotic ringspot or Prune dwarf • First leaves to emerge in the spring have prominent white veins on their upper surface Cherry leaf roll virus with either Prunus necrotic ringspot or Prune dwarf viruses Healthy National Clean Plant Network- Fruit Trees

CLRV & Prunus necrotic ringspot or Prune dwarf • Some leaves will have growths underneath Cherry leaf roll virus with either Prunus necrotic ringspot or Prune dwarf viruses National Clean Plant Network- Fruit Trees

CLRV & Prunus necrotic ringspot virus • Small leaves • Poor leaf color • Shoot die back • Poor terminal growth • Decline overwhelms other symptoms Cherry leaf roll virus and Prunus necrotic ringspot virus National Clean Plant Network- Fruit Trees

Trees WILL NOT recover from CLRV • Cutting back trees WILL NOT stimulate new growth • Delayed tree removal puts other trees in yours & your neighbor’s orchard at risk of infection National Clean Plant Network- Fruit Trees

Correct diagnosis is Essential Cherry leaf roll virus and Prunus necrotic ringspot virus Bacterial Canker Pseudomonas syringae National Clean Plant Network- Fruit Trees

Other diseases have similar symptoms Little cherry disease Cherry leaf roll virus Western X disease Rugose mosaic National Clean Plant Network- Fruit Trees

Other similar symptoms Summer oil application For control of mites, cherry fruit fly, powdery mildew National Clean Plant Network- Fruit Trees

Contact your local extension agent • If you recognize the symptoms of Cherry leaf roll disease, contact your nearest Cooperative Extension Office or specialist National Clean Plant Network- Fruit Trees