AgFirst, Hawkes Bay
Signals are that orchard labour may become a problem next season. We need to make trees more worker friendly. This means bringing a larger proportion of the marketable crop closer to the ground. Aim to reach about 60% of the marketable crop from the ground. This means improving light levels within the lower tree.
Focus your pruning effort on eliminating large, shading upper tree branches to allow more light past them into the lower canopy. Above the 2.5m level, there needs to be “in row” gaps between the trees to enable light to reach the lower canopy.
In most trees planted intensively, upper tree structure needs little more than spurs and weak fruiting laterals with good terminal fruiting buds.
In the lower tree, stronger branches producing excessive annual shoot growth may also need removal.
At individual branch level, fruiting wood should be confined to a single layer horizontal plane to avoid within branch shading. This means removal of any uprights, overlapping laterals and anything underneath the branches.
Where lower branches have been cut back hard to allow machinery access, remove this too as the severe heading cuts will stimulate excessive annual shoot growth.
Once the high growth, unwanted branches have been removed, the remaining calmer branches should be left more or less unpruned except for the removal of any vertical shoots.
Often where tree canopies are too dense, removal of problem branches has been too timid. Providing detailed pruning is minimised, its possible to remove a quarter, to a third of the branches without stimulating excessive tree vigour.
In the lower canopy, its often difficult to stimulate good replacement lateral growth from the leader. This problem can be overcome by leaving a two or three bud stud where branches are being removed, rather than flush cutting.
Where leader topping is required to lower tree height, this is best left until after fruit set, say mid-November, to minimise the vigour response from these cuts.
In situations where vigour is really excessive, pruning and crop load alone will not solve the vigour problems. Other vigour control methods need to be considered such as late dormant root pruning, trunk girdling or growth regulators.