Pruning Grapevines: Buds, Nodes & Shoots

1. How to Prune Grapevines Part One Buds, Nodes & Shoots Tim Creagh Lecturer in Viticulture

2. Introduction Pruning is one of the most important operations carried out in the vineyard and is one of the most expensive and time consuming

3. Introduction Pruning time gives the opportunity to: • Regulate the form and size of the vine • Regulate the vigour of the vine • Regulate the quantity (yield) and quality of the grapes

4. It Starts in the Bud The bud contains the shoot, the leaves, tendrils and flowers, ready to burst and grow in spring A bud is found in the nodes of grapevine shoots These buds appear single but in fact, comprise at least three 'true' buds and a lateral bud

5. Bud Node

6. Internode

7. Cut the node in half and you can see the buds Bud

8. Shoots Tendril • In spring the main bud bursts to become a shoot Leaf • The shoot will produce the flowers that become the fruit Flowers

9. Shoots As well as producing fruit for this season the shoot develops the buds for next seasons growth Later on the shoots harden, turn brown and become canes

10. The shoot………. becomes the cane

11. Canes • A shoot becomes a cane after periderm formation • From these canes will come the shoots that will carry the crop for the next season • But canes will only produce fruit if they come from buds that have been left deliberately (if you can count them) • Otherwise....

12. They are Watershoots The difference between a watershoot and a count shoot is....

13. Watershoots • Count shoots from count nodes • Watershoots from nowhere

14. Therefore… • Pruning is a matter of leaving count nodes • Count nodes are the nodes that you deliberately leave at pruning • Count nodes are always from wood (canes) that grew in the last season • These canes come from count nodes from the previous season • They are not from watershoots

15. Recap…… • Nodes contain buds • The main bud bursts to become a shoot • The new shoot produces the flowers which become the fruit • At the same time the new buds are forming in the shoot • Shoots become canes when they turn brown • Only canes that come from deliberately left buds are used for pruning which are found on count nodes

16. Before we move on • Basal bud • A bud at the base of a cane • They don’t normally burst in the same season as buds at nodes • These can remain dormant for many years • But when they do burst they produce.... • Blind buds • Buds that don’t burst

17. Watershoots • Watershoots come from buds that have been dormant • But during this time they lose the fruitfulness • And that’s why they look like they come from nowhere!

18. One last thing! • Bud swell and bleeding • Bud swell is when the buds swell and become fluffy just before budburst

19. Bleeding • When a cane, spur or cordon is cut close to bud burst time the cut 'bleeds' • Bleeding is due to increased sap flow within the vine, which brings carbohydrate from the roots and trunks • It can also bleed early on in the pruning season if it rains heavily followed by warm weather

20. Next…..Cane Pruning