Sarah de Bruin
Timeliness of tree training into a 2D canopy ensures the canopy remains calm and the trees continue to be balanced. Regular attention is required to fill the structure with the right branches and establish the trees within the system. Narrow, calm branches need to be brought down and secured onto the wires. Tying down branches regularly through the season, starting when the branches have a length of 25-30cm, will improve bud density and lower vigour.
Decision making for which branches to tie down may seem intimidating, but can be broken down into three simple rules:
- Fill the wires
- Bring down a branch closest to the wire
- Choose branches less than 30 % of the trunk diameter
Leaving wires bare reduces the potential yield in this system. It is important to fill the wires with any available branch options rather than missing an opportunity. Unideal branches can always be replaced with better options further down the track.
Trained in branches should come from within the target zone of 80mm above and 50mm below the wire. Branches within this zone create a wide crotch angle, greater than 45 degrees when secured to the wire. This promotes the best sap flow and the least vigour. If the angle is too steep between the branch and the leader, a vigour response will occur off the back of the branch.
Branches which are less than 30% of the trunk diameter should be trained in. Thicker, heavier branches have a heavier sap draw. The tree will allocate resources to these heavy branches, reducing the allocation for vertical growth.
If the canopy is young, the focus should be directed to filling the bottom wires. The taller the tree grows, the harder it becomes to direct sap flow to the lower branches. Once these bottom wires have been established, attention can shift to further up the tree.
Using the three simple tree training principles in a timely and systematic approach, will help to achieve the uniform interception of available light and grow consistent and highly coloured fruit.