How to develop the two-leader branchless tree
Plant the right type of nursery tree (cont from last issue)
To give your trees a good start in life and develop a full canopy of an Open Tatura Ground-Level Production System in less than three years, you need to start with moderate-size whips—which are nursery trees without feathers and have good root systems.
With the ground level production system that does not need branches, planting well-developed nursery trees is not required because quick development of leaders and fruiting units to fill the trees’ spaces is compensated for by low canopies and a high canopy surface area per hectare.
Roots are more important than tops.
Even a small reduction in tree price is important. For example, a 17 per cent cheaper tree can mean an increase in profitability of around 25 per cent. As plant material costs are of major importance for orchard economics, you should economise on this expenditure and use the most suitable trees.
Container-grown recommended
It is recommended you plant container-grown nursery trees in favour of bare-rooted nursery trees because:
• The window of planting bare-rooted fruit trees in winter is small. It is often a rush to prepare the block before the trees arrive and need to be planted, especially when the weather does not cooperate. If necessary, bare-rooted trees can be cold-stored for a few weeks, but we know that trees perform well when they are planted early in winter and as soon as possible after lifting.
• Water must move from the soil through the roots to the tree above the ground and into the air. This continuum is broken when trees are lifted in the nursery. The shock that trees can get when they lose many roots in the nursery, and then are transplanted into a different soil environment, can lead to poor or no growth of new roots. This is called transplant shock, and is often exacerbated when roots are not kept wet after lifting.
• With bare-rooted trees, there is also a potential problem when trees arrive in bundles and are heeled-in somewhere in the orchard or kept in cool storage. The roots inside the bundle easily miss out on being kept wet. This becomes obvious sometime after the trees have been planted when it is noticed that in a line of planted trees there are a few not doing well.
• During lifting, transport and planting, bare-rooted trees often have to put up with a lot of ‘abuse’, which results in broken roots and feathers, buds rubbed off and bark damaged.
• Use nursery trees with sleeping eyes only if trees are very expensive, or there are no 2-year-old trees available. A sleeping eye is a nursery tree with a dormant scion bud that is removed from the nursery the season before it normally would be for planting in the orchard. Planting sleeping eyes can significantly reduce the cost of establishment. However, you have to give the trees special attention when the bud becomes a shoot that will have to develop into two equal size leaders.
Container-grown nursery trees
Many of these problems can be prevented and early growth of roots and tops can be markedly improved when container-grown trees are used instead of bare-rooted dormant trees.
There are many advantages in purchasing and planting container-grown trees:
• Trees don’t need to be dug, heeled-in or held in cold storage. Trees can be full size when planted out into the orchard and still in the container they were grown in.
• Trees can be planted any time of year. One of the big advantages to growers is not losing a significant portion of the roots when the trees are dug up for transplanting in the orchard.
• Because the roots are not cut or disturbed, there is no transplant shock.
• Because the trees are initially grown in a green-house, the seedlings, or tissue-cultured rootstocks can be budded or grafted at any time of year.
• In the nursery, the trees can be grown in ‘air pruning’ trays to prevent root circling, which can be a problem with growing trees in pots or plastic tubes.
• Budding and grafting can be done conveniently, efficiently and is worker-friendly inside a shed on benches at waist-height, and without the weather interfering.
• Trees are easier to plant than bare-rooted dormant trees because smaller holes are needed.
• Container-grown trees develop many fine feeder roots which gives them a good start in the orchard.
• Container-grown trees have the potential to form a more uniform orchard and fill their space quicker and better than bare-rooted dormant trees.
Tree training (cont next issue)
See this article in Tree Fruit Nov 2023
This article is from the Orchard Manual: Open Tatura Ground-Level Production System
