Plant Disease Management Handbook

Cause Meloidogyne hapla, a nematode that lives in soil and attacks many other kinds of plants. Root-knot nematodes are sedentary endoparasites where only second-stage juveniles (the infective stage) and adult males (which may be rare) are found in the soil. The second-stage juveniles penetrate the tips of young roots.

See:

Strawberry (Fragaria spp.) - Virus Diseases

See:

Strawberry (Fragaria spp.) - Crown Rot

See:

Strawberry Cultivar Susceptibility

Note the red blotches on the leaves and on the unripened fruit.

Photo by Jay W. Pscheidt, 1994.

Cause Botrytis cinerea, a fungus that overwinters as sclerotia or dormant mycelia in old leaves, petioles, and mummified fruit. Plants from nurseries can also be a source of fungi including ones that are resistant to fungicides. Conidia from within the planting are the principal inoculum and are produced readily and for a long time on diseased plant material. Conidia may infect leaves but infections generally remain symptomless until the leaf dies.

Image related to Strawberry (Fragaria spp.)-Gray Mold (Fruit Rot)

Note the gray, fuzzy growth over these berries.

Photo by Jay W. Pscheidt, 1994.

Soft, rotted fruit with a gray mold over the surface.

Dept of Horticulture, OSU

A basket of moldy berries.

Photo by Jay W. Pscheidt, 1997.

Although Botrytis generally occurs on mature fruit it can develop on flowers under ideal conditions.

Jay W. Pscheidt, 2020.

See:

Strawberry (Fragaria spp.) - Leather Rot

Strawberry (Fragaria spp.) - Red Stele

Image related to Strawberry (Fragaria spp.)-Crown Rot

The entire plant may wilt soon after young leaves become off-colored then collapse and die.

OSU Plant Clinic Image, 2014.

The vascular system of the crown is discolored with dark shades of brown.

OSU Plant Clinic Image, 2014.

See:

Strawberry Cultivar Susceptibility

Note the small leaf spots with gray centers and purple borders.

OSU Extension Plant Pathology Slide Collection, 1984.

Image related to Strawberry (Fragaria spp.)-Common Leaf Spot

Note that most of the leaf spots on this plant are near the ground and on older leaves.

Jay W. Pscheidt, 1991.

Black seed and necrotic leaf spots.

Photo by Melodie Putnam.

Small gray leaf spots with purple boarders.

Neil Bell, 2017.

See:

Apple (Malus spp.) - Replant Disease

Strawberry (Fragaria spp.) - Charcoal Rot

Image related to Strawberry (Fragaria spp.)-Black Root Rot Complex

Roots turn necrotic and do not function for water or nutrient uptake.

OSU Extension Plant Pathology Slide Set, 1982.

Note the many necrotic roots on this plant.

OSU Extension Plant Pathology Slide Set.

The roots on the right side are starting to turn necrotic near the crown.

Melodie Putnam, 2007.

See:

Blackberry (Rubus spp.) - Armillaria Root Rot

Note Out of hundreds of samples there have been 19 that were diagnosed with Armillaria root rot by the OSU Plant Clinic.

Image related to Strawberry (Fragaria spp.)-Armillaria Root Rot

The fungus has attacked the crown of these plants.

OSU Extension Plant Pathology Slide Set, 1964.

The fungus can be seen as white threads near the center of this picture.

OSU Extension Plant Pathology Slide Set.

Cause Several Colletotrichum spp. can cause various anthracnose diseases of strawberry. C. acutatum has been found by the OSU Plant Clinic. This is now considered a species complex where C. nymphaeae predominates on strawberry and C. fioriniae is less frequently found. The diseases of fruit and crown rot were not a problem in the 1900s but were found more often in 2000s.

Image related to Strawberry (Fragaria spp.)-Anthracnose

Crown rot may first be seen as wilting of the entire plant with the youngest leaves appearing to recover but eventually the whole plant dies.

OSU Plant Clinic Image, 2012.

Fruit spots rapidly develop into firm, round lesions that turn dark-brown to black.

Jay W. Pscheidt, 1992.