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Timber rot/white mold/drop (Sclerotinia spp.) can affect most vegetable crops. Infections girdle stems, eventually killing whole plants or causing damping off in leafy greens. White mycelium covers affected tissue under humid conditions; under drier conditions, elongated lesions appear bleached or tan. Infected fruit become limp and rotten; this phase occurs most commonly on tomatoes. Dark brown to black overwintering structures (sclerotia) are often formed on and within diseased tissues. 

Sclerotinia white mold/timber rot on trellised cucumber.

(Photo: Emily Pfeufer, University of Kentucky)

Sclerotinia white mold/timber rot on carrot.

(Photo: Emily Pfeufer, University of Kentucky)

Sclerotinia white mold/timber rot resulting in fruit

drop on tomato.

(Photo: Emily Pfeufer, University of Kentucky)

Sclerotinia white mold/timber rot black sclerotia in

decayed tomato fruit.

(Photo: Emily Pfeufer, University of Kentucky)

Sclerotinia white mold/timber rot within a tomato stem.

(Photo: Kenneth Seebold, University of Kentucky)

Management:

• Remove diseased plant parts or entire plants, as well as sclerotia; burn infected debris or dispose of in uncropped areas far from structures.
• Maintain a weed-free border around structures.
• Apply labeled fungicides or biocontrol products preventatively where this disease has previously been a problem.

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