little cherry virus 2
TRANSCRIPT
Little cherry virus -2Little cherry virus -2 Facts and controlsFacts and controls
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Symptoms Symptoms
•Small cherriesSmall cherries
•Higher packing house Higher packing house cull percentage cull percentage
•Negative impact on Negative impact on color, shape & tastecolor, shape & taste
10.5 row Lambert & Royal Ann10.5 row Lambert & Royal Ann
Little cherry virus -2 samplesLittle cherry virus -2 samples
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SymptomsSymptoms•Bing & Sweetheart Bing & Sweetheart
relatively tolerantrelatively tolerant
•Severe symptoms Severe symptoms first year of infectionfirst year of infection
•Fruit size & color Fruit size & color return to return to NEARNEAR normal, but still normal, but still reducedreduced
•Fruit flavor never Fruit flavor never recoversrecovers
Replace this picture Replace this picture with picture ofwith picture ofBings and/or Bings and/or
Sweethearts with little Sweethearts with little cherry viruscherry virus
Little cherry virus-2 on ‘Sweetheart’
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Pathogen
Little cherry disease can be caused by one Little cherry disease can be caused by one of two agentsof two agents– Little cherry virus -1Little cherry virus -1
• Prevalent in Eurasia, but also with limited distribution in Prevalent in Eurasia, but also with limited distribution in North AmericaNorth America
• Insects that transmit this virus are unknownInsects that transmit this virus are unknown
– Little cherry virus -2Little cherry virus -2• Most common form of the disease found in western Most common form of the disease found in western
North AmericaNorth America• Transmitted by at least one species of mealybugTransmitted by at least one species of mealybug
Western X disease appears similarWestern X disease appears similar– Actually caused by special group of bacteriaActually caused by special group of bacteria
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TransmissionTransmission
•Apple mealybugs Apple mealybugs spread the little cherry spread the little cherry virus-2virus-2– Can be controlled with Can be controlled with
insecticide sprayinsecticide spray
•It is highly likely other It is highly likely other types of mealybugs types of mealybugs transmit the virus, but transmit the virus, but not confirmednot confirmed
Apple mealybugsApple mealybugs
Grape mealybugsGrape mealybugs
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TransmissionTransmission
• Transmitted via grafts of non-certified Transmitted via grafts of non-certified budwood or rootstocks budwood or rootstocks
• Root grafting can pass virus on to Root grafting can pass virus on to healthy treeshealthy trees
• Best defense is to plant virus-tested Best defense is to plant virus-tested trees from certified nurseries. Click here trees from certified nurseries. Click here for a list of for a list of certified nurseries
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ControlControl
•Control mealybug vectorsControl mealybug vectors
•Control wild cherries Control wild cherries (bitter cherry) near (bitter cherry) near orchardorchard
•Immediate & proper Immediate & proper removal of infected trees removal of infected trees
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Proper tree removalProper tree removal
•As cut tree limbs start As cut tree limbs start to dry, the insects to dry, the insects (and viruses) may (and viruses) may move to nearby trees. move to nearby trees.
•To prevent vector To prevent vector (and virus) (and virus) movement.movement.– Apply good cover spray Apply good cover spray
of broad spectrum of broad spectrum insecticide/miticide to insecticide/miticide to tree about 7 days tree about 7 days before cutting.before cutting.
Goal: Prevent the spread of virusGoal: Prevent the spread of virus
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Proper Tree RemovalProper Tree Removal
• Or remove trees in Or remove trees in winter while insects winter while insects are dormant. are dormant.
•Remove all of the Remove all of the wood from the orchard wood from the orchard before mild spring before mild spring weather.weather.
Even though Bing and Sweetheart Even though Bing and Sweetheart trees can “bounce back” after trees can “bounce back” after virus infection, but they never virus infection, but they never
return to full production.return to full production.
Healthy cherry tree Healthy cherry tree surrounded by trees surrounded by trees
infected by little cherry infected by little cherry virus-2.virus-2.
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Things to consider
• Even when you remove an infected tree, the virus may still be a threat
• Keep an eye on surrounding trees for the next 2 to 3 years
• If in doubt, have trees tested
Newly infected tree may take 2-3 years to show symptoms
Symptomatic tree to be removed
Root graft
Things to considerThings to consider
• Ignore the disease and Ignore the disease and it will continue to it will continue to spreadspread
– To nearby treesTo nearby trees– To your neighbors’ To your neighbors’
orchardsorchards
•Little cherry disease Little cherry disease reduces economic reduces economic viability of your orchard viability of your orchard
– Decrease in yieldDecrease in yield– Increase in cullsIncrease in culls– Fruit flavor never Fruit flavor never
recoversrecovers
Above: Cherries with little cherry Above: Cherries with little cherry virusvirus
Below: Virus-free Bing cherriesBelow: Virus-free Bing cherries
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Questions?Questions?
Tim SmithTim Smith
WSU Extension EducatorWSU Extension Educator
Dr. Ken EastwellDr. Ken EastwellFruit Tree Clean Plant NetworkFruit Tree Clean Plant NetworkWSU-Prosser IARECWSU-Prosser [email protected]
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