Mouldy grapes?

[carlofbrigg]

i have a black grape vine growing under glass which this year and last year has produce a large crop of fruit which turns mouldy- white powdery mould on the fruit,before and during ripening

i have no clue to what it is or how to treat it ,any help greatly appreciate

only other items in greenhouse are tomatoes and a few cacti

[Geordie]

Grapes

Carl,

This sounds like powdery mildew or more specifically 'grape powdery mildew'. It would normally start on the underside of leaves, progress to the foliage before attacking the bunches of grapes. Generally powdery mildew on one plant will not spread to a different type of plant.

Try and thin out some of the vine growth this winter. Overcrowding is a major factor in mildew type diseases. Next year you need to ensure good ventillation and can spray vines with a sulphur based fungicide.

Hope this helps...grapes are worth persevering for!