Cherry Pests and DiseasesCherry Pests and Diseases

Rest Breaking Treatments for Rest Breaking Treatments for Sweet CherriesSweet Cherries

Joe GrantFarm Advisor

UC Cooperative ExtensionSan Joaquin County

National Cherry Growers of AustraliaAnnual Conference

July, 2004

Joe GrantJoe GrantFarm AdvisorFarm Advisor

UC Cooperative ExtensionUC Cooperative ExtensionSan Joaquin CountySan Joaquin County

National Cherry Growers of AustraliaNational Cherry Growers of AustraliaAnnual ConferenceAnnual Conference

July, 2004July, 2004

CHERRY PEST MANAGEMENT CALENDAR OF OPERATIONSJoe Grant, UC Farm Advisor, San Joaquin County

DecemberNovemberOctoberSeptemberAugustJulyJuneMayAprilMarchFebruaryJanuary

Bloom stimulation spray

Delayed dormant spray Fruit worms

Bloom disease sprays

Earwig bait

Preharvest decay control

Spot-treat spring & summer weeds Strip weed spray

Control Cherry Buckskin vectors

Mites Bordeaux spray

This calendar lists typical timings of practices conducted in a sweet cherry orchard. Specific needs will determine if the practice is necessary.

Pocket gophers

Bacterial canker & blossom blast

Phytophthora root & crown rot

Cherry Buckskin Disease (Western X Disease) High-worked Mahaleb tree

Mountain Leafhopper

Flor’s LeafhopperCherry (Flor’s) Leafhopper

Cherry Stem Pitting Disease

Blossom & fruit rots Brown rot blossom blight and fruit rotBotrytis blossom blightRhizopus fruit rot

Powdery Mildew, Podosphera clandestina

Green Fruitworm, Orthosia hibisciGreen Fruitworm, Orthosia hibisci

Fruittree Leafroller larvae & adult

Obliquebanded Leafroller larvae & adult

March April May June July Aug. Sept.

Larvae

Larvae

Eggs

Pupae

Adults

Adults

Pupae

Eggs

Blo

omB

loom

Obliquebanded leafroller

Fruittree leafroller

March April May June July Aug. Sept.

Webspinning spider mites

Cherry slugCherry slug

European EarwigEuropean Earwig

ScalesScales

BirdsBirds

Occasional Pests

Wood borersWood borers

Cherry VirusesCherry Viruses•• PrunusPrunus Necrotic Necrotic RingspotRingspot VirusVirus•• Cherry Cherry RaspleafRaspleaf•• Cherry Necrotic Rusty Mottle Cherry Necrotic Rusty Mottle

VirusVirus

NematodesNematodes•• Lesion Nematode (Lesion Nematode (P. P. vulnusvulnus))•• Ring NematodeRing Nematode

Cherry raspleafCherry Cherry raspleafraspleaf

Cherry crinkle

Suture, doubles, spursAbiotic DisordersAbioticAbiotic DisordersDisorders

Rest Breaking Treatments for Rest Breaking Treatments for Sweet Sweet CherriesCherries

Dormancy/RestDormancy/Rest

Lack of chilling causesLack of chilling causes–– Straggly leafing & bloomStraggly leafing & bloom–– Weak bloom, abnormal flowersWeak bloom, abnormal flowers–– Bud deathBud death–– Uneven fruit growth & maturityUneven fruit growth & maturity

Average Chilling Accumulation Avg. of available San Joaquin County stations

92/931236

674

95/96

867

97/98

98/991410

92999/00

00/01

1430

01/02

986

02/03

94603/04

0

200

400

600

800

1000

1200

1400

1600

11/15 12/15 1/15 2/15 3/15

DATE

HO

UR

S <

45F

0 400 800 1200 1600 2000

FigAlmondApricotPeachCherryWalnut

PlumPear

ApplePrune

0 400 800 1200 1600 2000

FigAlmondApricotPeachCherryWalnut

PlumPear

ApplePrune

Hours < 45 °FHours < 45 Hours < 45 °°FF

Approximate Chilling Requirements of Selected Fruit & Nut Crops

Approximate Chilling Requirements of Selected Approximate Chilling Requirements of Selected Fruit & Nut CropsFruit & Nut Crops

Chilling requirementChilling requirement

Varies:Varies:•• CropCrop•• VarietyVariety•• RootstockRootstock•• Among buds on a treeAmong buds on a treeCalifornia cherries: 850 hrs.California cherries: 850 hrs.

EndodormancyParadormancy Ecodormancy

SummerSummerSummer SpringSpringSpringWinterWinterWinterFallFallFall

Stages of dormancyStages of dormancyStages of dormancy

Short daysLow temperatures Short daysShort daysLow temperatures Low temperatures Warm temperaturesWarm temperaturesWarm temperatures

Hormones from terminal buds & leaves

Hormones from Hormones from terminal buds & terminal buds & leavesleaves

DehydrinsBound waterMembrane changesLow metabolism

DehydrinsDehydrinsBound waterBound waterMembrane changesMembrane changesLow metabolismLow metabolism

HormonesFree waterHormonesHormonesFree waterFree water

Environmental changesEnvironmental changesEnvironmental changes

Biological changesBiological changesBiological changes

Chilling ModelsChilling Models

Hours Hours << 45 45 °°FF

“Utah” Chill Units“Utah” Chill Units

Dynamic ModelDynamic Model

Chilling ModelsChilling Models

Hours Hours << 45 45 °°F (7 F (7 °°C)C)•• Less than 45 Less than 45 °°F (1934)F (1934)•• Less than or equal to 45 Less than or equal to 45 °°F (1950)F (1950)

323235354040454550505555606065657070

000.50.51.01.0

0.50.500

-- 0.50.5-- 1.01.0

“Utah” Chill Units Model, Richardson, et al, 1974

“Utah” Chill Units Model, , RichardsonRichardson, et al, 1974, et al, 1974

CUoFMost effectiveMost Most effectiveeffective

-- 2.02.0

Dynamic ModelDynamic ModelFishmanFishman, et al, 1987, et al, 1987

“Chilling Portion”““Chilling Portion”Chilling Portion”

HeatColdHeatHeatColdCold

Rest breaking materialsRest breaking materials

Oil Oil

DORMEXDORMEX

CAN 17 + SurfactantCAN 17 + Surfactant

Calcium nitrate Calcium nitrate ++ ErgerErger GG

Rest breaking treatmentsRest breaking treatments

Response variable, depending on:Response variable, depending on:•• DoseDose•• Time of applicationTime of application•• Conditions at/after applicationConditions at/after application•• Bud developmentBud development•• Extent of chilling deficitExtent of chilling deficit

Rest breaking treatmentsRest breaking treatments

DORMEXDORMEX generally more effective than generally more effective than CAN 17CAN 17

More consistent response when time More consistent response when time sprays sprays using CP using CP

DormexDormex: 42: 42--50 CP50 CPCAN 17: 54CAN 17: 54--58 CP58 CP

Easier to compact than advance bloomEasier to compact than advance bloom

Effect on fruit ripening less than bloomEffect on fruit ripening less than bloomSurfactants vary in effectiveness and Surfactants vary in effectiveness and riskrisk of of

phytotoxicityphytotoxicity

Bing, 2004Bing, 2004Bing, 2004

CAN 17 + 2% EntryCAN 17 + 2% EntryCAN 17 + 2% Entry

CAN 17 + Entry CAN 17 + Entry CAN 17 + Entry Dormex + Agri-dexDormexDormex + + AgriAgri--dexdex

Bing, G & S, 2004 50 CPBing, G & S, 2004 50 CPBing, G & S, 2004 50 CP