Review of strawberry Diseases in California-Steven Koike
Review of strawberry Diseases in California-Steven Koike
Review of strawberry Diseases in California-Steven Koike
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<strong>Review</strong> <strong>of</strong> Strawberry<strong>Diseases</strong> <strong>in</strong> <strong>California</strong><strong>Steven</strong> <strong>Koike</strong>University <strong>of</strong> <strong>California</strong>Cooperative Extension
FoliarFruit• Angular leaf spot• Anthracnose• Common leaf spot• Phomopsis leaf bl.• Leaf blotch• Powdery mildew• Gray mold• Anthracnose• Rhizopus rot• Mucor rot• Leather rot• Powdery mildew
FoliarFruit• Angular leaf spot• Anthracnose• Common leaf spot• Phomopsis leaf bl.• Leaf blotch• Powdery mildew• Gray mold• (Anthracnose)• Rhizopus rot• Mucor rot• Leather rot• Powdery mildew
Commonleaf spot
Leaf blotch
Angular leaf spot
Angular leaf spot
Powdery mildew
Gray mold
AnthracnoseRhizopusMucor
Recent developments• Dieback/collapse first noticed <strong>in</strong> 2005.• Increas<strong>in</strong>g <strong>in</strong>cidence through 2011.• Not associated with Phytophthora,Verticillium, or other pathogens.• In fields without MB/CP flat fumigation• Two pathogens responsible:– Macrophom<strong>in</strong>a phaseol<strong>in</strong>a– Fusarium oxysporum f. sp. fragariae
Recent developments• Distribution:– Initially <strong>in</strong> southern CA (Orange, Ventura)– Now occurr<strong>in</strong>g <strong>in</strong> other parts <strong>of</strong> CA• Symptoms:– Plant wilt<strong>in</strong>g– Poor growth– Plant collapse and death– Discoloration <strong>of</strong> crowns
Charcoal rot
M. p.
Distribution• Macrophom<strong>in</strong>a on <strong>strawberry</strong>:Argent<strong>in</strong>a, Australia, Egypt, France,India, Israel, Spa<strong>in</strong>, USA (CA, FL, IL).• <strong>California</strong> <strong>strawberry</strong>:– 2005-2009: Orange, Ventura, SantaBarbara, San Luis Obispo, Alameda,Sacramento counties– 2010-2011: Santa Clara, Santa Cruz,Monterey counties
The march <strong>of</strong>Macrophom<strong>in</strong>a20052009
The march <strong>of</strong>Macrophom<strong>in</strong>a2011
Fusarium wilt
F<strong>of</strong>
Distribution: Fusarium• Fusarium on <strong>strawberry</strong>: Argent<strong>in</strong>a,Australia, Ch<strong>in</strong>a, S. Korea, Spa<strong>in</strong>,Japan, USA (CA, SC)• <strong>California</strong> <strong>strawberry</strong>:– Ventura County– (Monterey: one corner <strong>of</strong> one field <strong>in</strong> 2009;was later fumigated)
Fusarium oxysporumf. sp. fragariae2006 2011
2011:Verticilliumoutbreaks?
Verticillium wilt
Phytophthoraroot and crownrot / fruit rot
Diagnosis?
Diagnostic challenge I:identical symptomsSymptoms Macroph. FusariumPoor growth yes yesStunt<strong>in</strong>g yes yesDieback yes yesPlant collapse yes yesCrown discolored yes yesStress related yes yes
Diagnostic challenge II:similar symptomsSymptoms Mac. Fus. Verticillium Phytoph.Poor growth yes yes yes yesStunt<strong>in</strong>g yes yes yes yesDieback yes yes yes yesPl. collapse yes yes yes yesCrown discolor yes yes no yesStress yes yes yes noAssoc. w/ H2O no no no yes
Management: soilborne diseases• Site selection: avoid <strong>in</strong>fested fields.• Crop rotation: plant non-hosts.• Pre-plant fumigation: still useful.• Sanitation: don’t move <strong>in</strong>fested mud,contam<strong>in</strong>ated equipment.• “Resistance”: use tolerant (?) cultivars.• Production: reduce plant stress.
USDA