When the leaf is turned over, a greenish mold may be associated with the colored areas. Timber rot is caused by Sclerotinia sclerotiorum . This fungal disease will be more common in greenhouses which have been infected in the past. Without careful removal of the diseased vines, the hard resting structures which were produced inside the stem will fall out. Some will be located in an area where they can germinate and produce spores.
Infection usually occurs where fallen flower petals have lodged or in leaf axils.
The growing fungi produce water soaked areas in the stem which become soft and eventually turn a bleached, white or grey when they dry. Infected fruit is gray and goes to a rapid watery rot. Prevention is the best management for these diseases. Scout your greenhouse regularly. Keep the air inside the greenhouse moving, reduce free water and lower the relative humidity.