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Common spot of strawberry

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**Symptoms and Effects:**
– Circular spots on leaves, ⅛ to ¼ inches across
– Dark borders on spots
– Centers of spots may turn tan or gray
– Spots may merge into larger lesions
– Infected fruit may have sunken spots
– Disease can lead to foliage death, stunting, or plant death
– Black seed disease can discolor fruit achenes
– Reduced yield and poor quality strawberries
– Economic impact on farm profitability

**Disease Cycle and Environment:**
– Pathogen overwinters in leaf debris
– Spread through rain splash
– Thrives in cool temperatures, high humidity, and wet conditions
– Polycyclic disease capable of reinfection
– Two spore types: conidia spores and ascospores
– Optimal temperature for growth around 25°C
– Favors 12+ hours of leaf wetness for infection
– Young foliage more susceptible
– Severe infections in mid to late spring

**Prevention and Management:**
Plant disease-resistant cultivars
– Proper spacing for air circulation
– Mulching to prevent soil splash
– Avoid overhead irrigation
– Remove and destroy infected plant debris
– Use fungicides with recommended application times
– Cultural practices like pruning for airflow
– Monitor and detect early
– Integrated pest management approach

**Importance and Economic Impact:**
– Disease had significant economic impact before resistant cultivars
– Can cause serious reductions in yields
– Does not kill plants but affects foliage and fruit quality
– Manageable compared to other diseases
– Development of resistant cultivars has improved control

**Causes and Spread:**
– Fungal pathogen Colletotrichum acutatum
– Spread through splashing water or wind
– Thrives in warm, humid conditions
– Overwinters in plant debris
– Entry points through wounds or natural openings

Common spot of strawberry is one of the most common and widespread diseases afflicting the strawberry. Common spot of strawberry is caused by the fungus Mycosphaerella fragariae (imperfect stage is Ramularia tulasnei). Symptoms of this disease first appear as circular, dark purple spots on the leaf surface. Mycosphaerella fragariae is very host-specific and only infects strawberry.

Common spot of strawberry
Younger stadium of Mycosphaerella fragariae on strawberry
Common namesCommon leaf spot, leaf blight of strawberry
Causal agentsMycosphaerella fragariae

Common spot of strawberry
Older stadium of Mycosphaerella fragariae on strawberry
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Dothideomycetes
Order: Capnodiales
Family: Mycosphaerellaceae
Genus: Mycosphaerella
M. fragariae
Binomial name
Mycosphaerella fragariae
(Tul.) Lindau, 1897
  • Cylindrosporium grevilleanum Tul.
  • Ramularia grevilleana (Tul.) Jørst., (1945)
  • anamorph Ramularia tulasnei Sacc., (1886)
  • Sphaerella fragariae (Tul. & C. Tul.) Sacc., (1882)
  • Sphaeria fragariae Tul., (1856)
  • Stigmatea fragariae Tul. & C. Tul., (1863)
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