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Compendium of Diseases of Crops: Strawberry

Manilyn is a part time writer and a part time farmer. She is very much interested in topics like Farming and Food Marketing.

Strawberry Diseases

1. Leaf Scorch (Marsonina earlianum)

Symptoms

Irregularly-shaped purple spots occur on leaves. The spots may later enlarge or merge into brown lesions that look burnt. Fruiting bodies grow at the center of the old spots.

The disease is prevalent during rainy season and in damp areas. It may affect the petioles, stolons and fruit stalks.

Management of Disease:

  • Sanitation practices such as removal and proper disposal by burying or burning of infected leaves.
  • Sanitation can be supplemented with spraying of recommended fungicide preferably when leaves of plants are dry.
Leaf Scorch caused by Marsonina

Leaf Scorch caused by Marsonina

2. Leaf Spot (Mycosphaerella fragariae)


Symptoms

Circular spots on affected leaves measureform 1/8 to 1/4 inch in diameter. The disease differs from scorch in that spots are dry and whitish gray at the center surrounded by a purple or violet halo. The fungus may also affect the fruit and cause a symptom known as "black seed". Infection may extend to fruit stalks, stolons and calyces.

Management of Disease:

  • Sanitation practices such as removal and proper disposal of infected leaves by burying or burning
  • Sanitation can be supplemented with proper timing of spray using recommended fungicides
Leaf Spot caused by Mycosphaerella

Leaf Spot caused by Mycosphaerella

3. Leaf Blight / Anthracnose (Colletotrichum Sp.)

Symptoms

Spots are colored brown to black and irregular in shape. Symptoms may occur on the leaf blade, leaf margins or leaf tips.


Management of Disease:

  • Apply the recommended rate of nitrogen fertilizer for strawberry.
  • Plant disease-free planting materials and use resistant varieties that are available.
Leaf blight / anthracnose on leaf

Leaf blight / anthracnose on leaf

4. Anthracnose (Colletotrichum gloeosporioides)

Symptoms

The affected part of the fruit appears as firm rot. Lesions are light brown. White mycelia of the fungus grows at the edge of the lesion. Unripe fruits are also infected by pathogen.

Management of Disease:

  • Use of black plastic mulch to prevent fruits from touching the soil
  • During fruiting stage, do not water late in the afternoon. This practice promotes rotting of fruits
Fruits with anthracnose

Fruits with anthracnose

5. Gray Mold Rot (Botrytis cinerea)

Symptoms

On the infected berries, light brown spots appear which increase rapidly until the whole fruit becomes brown and rotten. Gray dusty mold (fungal mycelium and spores) develops onn affected part of the fruit. Both green and red fruit are susceptible to infection. However, the disease develops faster on ripe fruits.

Management of Disease:

  • Remove and bury infected fruits to minimize the spread of the disease
  • Remove and burn infected plant materials. Don't leave them in the canals or in between plots.
Gray mold rot on fruits

Gray mold rot on fruits

6. Phytophthora Rot (Phytophthora sp.)

Symptoms

Rotted portion of infected fruits are colored brown. Favorable environmental conditions encourage growth of fungus that appear as white cottony (mycelia) on the rotted portion. The fungus may infect unripe fruits.

Management of Disease:

  • Remove and bury infected fruits to minimize the spread of the disease
  • Remove and burn infected plant materials. Don't leave them in the canals or in between plots.
Fruits infected with Phytophthora rot

Fruits infected with Phytophthora rot

7. Fusarium Wilt (Fusarium oxysporum)

Symptoms

Wilting is initially seen on matured leaves. Leaves of infected plants roll during warm weather. As the disease progresses, the fungus affects the crown and causes it to rot. Brown discoloration of water-conducting tissue is seen when roots are cut lengthwise.

Management of Disease:

  • Avoiding too much nitrogen fertilizer.
  • Soil solarization during days with long sunshine.
  • Application of systematic fungicides recommended for Fusarium.
Fusarium wilt symptom

Fusarium wilt symptom

8. Crinkle (Crinkle mosaic virus)

Symptoms

infected leaves at the center of the whorl are crinkled and chlorotic (yellowish).

Management of Disease:

  • Disease spread may be prevented by using pan traps, sticky traps or low dosage of recommended insecticides against aphids and thrips which are the more common vectors of the disease.
Crinkling and chlorotic symptoms on leaves

Crinkling and chlorotic symptoms on leaves

Comments

Jennifer Jorgenson on June 05, 2019:

I will definitely be referring to this later. Thank you for creating such a thorough article. I've seen some of these issues on mine and my mom's strawberries. Now I know what's going on and how to treat it! Thanks again.