Q How do I recognise shanking in grapes?

A Bunches of grapes affected by shanking appear to develop normally, but then individual fruits within the bunch fail to colour up in the usual way; green varieties remain translucent and black varieties become red. If eaten, these grapes usually have a rather sour and watery taste. Soon afterwards, the affected grapes become wrinkled and, if left on the bunch, may become raisin-like.

Caption: Shanking ruins the quality of grapes.

Q What can do if my grapes are affected by shanking?

A Check that the grapevine is properly, but not excessively, watered and fed. Use sharp scissors to remove affected grapes, then apply a foliage feed at two-week intervals to encourage any remaining and subsequently formed grapes to develop normally.

Q What can I do to prevent shanking?

A Shanking is generally caused by incorrect cultural conditions – most commonly over- or underwatering, and occasionally underfeeding. Making sure that growing conditions are perfect should prevent the problem.