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Strawberries: Leaves are brown, burned, or necrotic

Look for patterns in the field to help distinguish between:

Overfertilization

Look for a rather uniform pattern of injury, appearing suddenly. Burn resulting from ammonium fertilizers applied just prior to wet, warm weather.

Strawberry leaf covered in maroon speckles
Overfertilization injury from ammonia application in wet, warm weather.
Strawberry leaves with off-center V-shaped necrosis. Living tissue is blemished by purple-edged marks with brown center.
Excessive chloride fertilizer.
Strawberry leaves with brown necrotic lesions along leaf edges.
Excessive boron application.

Herbicide Injury

Look for regular patterns in the field, such as at the ends of rows where the sprayer turned or every fourth row where spray overlap occurred, etc.

Strawberry leaf with yellowing and necrosis along veins, characteristic of herbicide injury.
Herbicide injury from terbacil exposure.

Four herbicides that can induce chlorosis and tissue death are carfentrazine ethyl (Aim EC), flumioxazin (Chateau / Valor),  oxyfluorfen (Goal), and terbacil (Sinbar).

Carfentrazone ethyl (Aim EC)

Carfentrazone ethyl is a contact herbicide that will cause spotting and necrosis in leaves, petioles, flowers, and fruit of exposed strawberry plants. It is meant to be applied before planting or in shielded sprays between rows. If carfentrazone drifts onto strawberry leaves, injury can occur quickly. Carfentrazone does not translocate through the plant, so if injury is not severe, new leaves can be unaffected.

Close-up of strawberry plant with leaves curled up and covered in dark brown necrotic lesions.
Carfentrazone ethyl injury.

Aim EC Usage Instructions; See group 13-07G for strawberry

Flumioxazin (Chateau / Valor)

Flumioxazin is a pre- and post-emergent herbicide that persists in the soil, providing residual grass and broadleaf weed suppression 4-8 months after application. Flumioxazin is meant to be applied peplant or to row middles and not directly to strawberry leaves. If drift occurs, burning and stunting can result with necrotic lesions on leaves, fruits, and flowers.

Strawberry plant in straw mulch. Mature leaves mottled brown with few green patches. Browning is veinal and interveinal, brown tissue is not dry. Young, green, healthy leaves are emerging from injured plants.
Flumioxazin injury.

 

Strawberry plants with brown spotting along leaf veins and interveinal margins.
Flumioxazin injury causes necrotic lesions along veins and in interveinal margins.

Herbicide Injury: flumioxazin (Chateau). NC State Extension.
Strawberries: Flumioxazin. OMAFRA.

Oxyfluorfen (Goal)

Oxyfluorfen is a pre- and post-emergent herbicide. This herbicide can be transported by water droplets, or water vapor, onto strawberry foliage. Injury causes symptoms ranging from interveinal necrosis, to leaf death, to total plant death. Leaves will develop brown, purple, or blackish spots upon exposure. It should only be used on dormant strawberry plants.

Close-up of strawberry leaf with patches of healthy green tissue, and mottled bronze-purple tissue. Necrotic tissue is along veins, between veins, and occasionally has spotting pattern corresponding to droplets.
Oxyfluorfen injury on mature strawberry leaf.

 

Strawberry leaves with veinal bronzing and purple discoloration along leaf margins.
Oxyfluorfen injury.

 

Strawberry leaves with veinal and interveinal bronzing, and purple spotting on leaf margins. Leaf petiole has red discolored patch.
Strawberry leaves and petioles with oxyflurofen injury.

Herbicide injury: Oxyflurofen (Goal). NC State Extension.

Terbacil (Sinbar)

Terbacil is a pre-emergent herbicide that reduces germination rates of non-grass weeds. Terbacil should be applied sparingly to soils with low (<1%) organic matter or low clay content, to avoid crop injury. Terbacil is water-soluble. If crop exposure is suspected, irrigating or otherwise washing off strawberry leaves and root zone can prevent injury. Terbacil is taken up through roots as well as foliage.

Symptoms of injury begin roughly 48 hours after exposure. Marginal or interveinal chlorosis can spread throughout entire leaves. Chlorotic tissues eventually die, and new shoot and root growth is stunted. Field regions with spray overlap are most susceptible to injury.

Strawberry plants with pronounced interveinal necrosis. Some leaves are not necrotic but have distinct chlorotic border on outer lead margin.
Terbacil injury causes marginal and interveinal tissue damage in leaves.

Herbicide Injury: Terbacil (Sinbar): NC State Extension
Strawberries: Terbacil. OMAFRA

Nutrient Deficiencies

Nutrient deficiencies, such as calcium, magnesium, or potassium tend to follow soil type or drainage patterns.

Calcium Deficiency

Interveinal necrosis and yellowing of leaf tips on strawberry plant.
Calcium deficiency symptoms in established plant.

 

Strawberry runner with browning of new leaves. Stem attached to runner has pinched, blackened appearance. Runner rootlets are black and underdeveloped.
Calcium deficiency in strawberry runner.

Potassium Deficiency

Potassium deficiency causes marginal burning and a dark discoloration of the leaves.

Deep purple discoloration on strawberry leaf. Discoloration begins at center of plant and travels outwards towards margins. Leaf edges have small, tan, necrotic lesions.
Potassium deficiency in strawberry.

Magnesium Deficiency

Progression of Mg deficiency symptoms in leaf, increasing from left to right. Proliferation of tan necrotic lesions along interveinal margins, most severe along leaf edges.
Magnesium deficiency in strawberry.

Use these resources if you need additional help with diagnosis and to find solutions to your problem.