Advice
Grape shanking
Shanking
is a disorder of grapes, occurring most commonly on indoor
vines. It begins as a brown area girdling the fruit stalk,
causing the affected grape or cluster to discolour and shrivel.
It is believed to be caused by one or more of the following
factors.
- Overcropping - avoid cropping young vines in the first two years, allow only three or four bunches in the third year, and on established vines do not exceed more than one bunch per lateral. Removal of surplus bunches may stall the onset of shanking if caught early.
- Excessive pruning when in leaf - stopping of laterals and sub-laterals should be done regularly during the growing season, not left to a single removal which can cause shanking in the current or following season.
- Impaired root action - drought or waterlogging at the roots can lead to fruit abortion.
- Pest and disease - shanking may occur if their action results in the damage of leaves (eg red spider mite or mildew) or loss of roots (e.g. vine weevil).
- It is also possible that late cold damage in unheated greenhouses and excessive nitrogen leading to soft growth are contributing factors to the problem of shanking.