Symptoms of Sclerotinia sclerotiorum on Cucurbitaceae

• Organs attacked :

• Symptoms :
  • Elongated lesions on stems  initiated from senescent or injured tissue (aborted fruits, tendrils, floral parts, senescent leaves, various injuries, etc.). These can be located near the collar or along the length of the stems. They have a wet and milky appearance, and end up encircling them for several centimeters (figures 1 to 3).
  • exudates  Reddish-brown salmon-colored gummy
  • The distal part of the girdled twigs, the leaves can turn yellow, wither and dry out.
  • Wet and dark rot developing on the fruits, at the level of the stylar scar or in contact with the ground (figures 5 to 8). It spreads rapidly and gradually generalizes; the fruits eventually shrivel up and/or collapse more or less completely.

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• Signs : more or less fluffy and white mycelium  on all affected tissues (figure 7), as well as large irregular black structures, sclerotia which are  rather elongated, measuring 2-20 mm x 3-7 (figures 6, 8, and 9). Small “trumpets”, apothecia, forming on the larger sclerotia.
• Possible confusion : Sclerotium rolfsii , Rhizoctonia solani aerial,

• Affected production areas :

• Reunion