Pruning in the vineyard - White Castle

Dr Delana Davies, Arable & Horticulture Technical Officer

Winter pruning of grapevines is a task that must be carried out every year during the dormant winter period. It is considered to be the most important task carried out during the vineyard year, because the way in which the vines are pruned has a strong influence over the following:

• The level of vigour with which vegetative growth is produced during the following summer season
• The potential yield of crop produced
• The potential grape ripeness levels that can be achieved
• Level of pressure from fungal diseases during the summer season
• The cost of grape production
• The risk of crop loss through spring frost damage
• The productive lifespan of the grapevine

The vine on the left has been pruned in a random manner, and a large area of die-back tissue has formed on the left hand side. No sap can flow through this area now, as it is dead tissue. The vine on the right has been pruned using small cuts restricted to young wood. This pruning method maintains an uninterrupted flow of sap from the roots, up the trunk and into the foliage.

The grapevine leaves are like solar panels. They absorb sunlight and convert this into carbohydrate. The vine then distributes this carbohydrate internally, apportioning it to its various organs, such as trunk, roots, buds and grapes.

More information is contained in this Fact Sheet.