Scouting for diseases: Sclerotinia
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EmailEditor’s note: This article is from the archives of the MSU Crop Advisory Team
Alerts. Check the label of any pesticide referenced to ensure your use is
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Pathogen: Sclerotinia sclerotiorum (View images).
Hosts Include: Anemone, Aquilegia, Aster, Bellis, Campanula,
Coreopsis, Delphinium, Digitalis, Helianthus, Hosta, Iris, Liatris,
Lupinus, Papaver, Platycodon, Rudbeckia and Scabiosa.
Symptoms: Pre- and postemergent damping-off, crown rot, and
blighting of foliage and petioles. Small, hard, irregular, black
structures called sclerotia may be present on or in plant tissue
(especially inside stem and petiole tissue). White, fluffy growth on
affected plant parts is most readily visible in high humidity.
Spread: Sclerotia, long-term survival structures, are found in
soil and on plant debris. The disease is primarily spread when these
structures are moved. Disease can also be spread when infected plant
material is moved.Under certain environmental conditions, mushroomlike
structures (apothecia) are produced. These release air- borne spores.
Management: Field soil should be sterilized before use in
growing media. Susceptible crops should not be grown in areas with a
history of white mold problems. Additionally, good sanitation is
important to limit spread. Control weeds in production areas – some
weeds are hosts to S. sclerotiorum. Fungicide drenches can protect
plants from infection.
