Symptoms of Sclerotium rolfsii on Lettuce

• Organs attacked :

• Symptoms :
  • Wet, brown lesions developing on leaves in contact with the ground (Figure 1). The rot sets in and gradually affects the collar, certain roots, the base of the petioles.
  • Generalized rot in the apple.
  • Wilting, yellowing of leaves, collapse of plants followed by their progressive decomposition.
  • Affected plants distributed in more or less wide foci.

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• Signs : dense whitish mycelium covering the damaged organs. Smooth structures, rather spherical (1 to 3 mm in diameter), initially white, then tawny to reddish brown, gradually visible within the mycelium: sclerotia resembling mustard seeds.

• Affected production areas :