tree form
The shape of a tree consisting of a trunk and a crown. It can be divided into single stem, multi-branch, alternating, inverted broom, lamp brush and umbrella bone. One of the characteristics of tree species is also related to site conditions, and is influenced by cultivation measures such as pruning and shaping.
Simple stem shape
A tree with an obvious trunk (that is, the central main branch, the same below) and relatively few and weak branches. For example, the tree of PR 107.
Multi-branch shape
Trees with inconspicuous trunk, low branches, many branches, large branches or many branches. This kind of tree often changes with the age of the tree, and some branches are eliminated. Such as the tree of RRIM600.
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There is a tree with obvious trunk and alternate main branches. This branch of the trunk has a large branch angle and can last for a long time. It is considered to be a reasonable crown structure, which is beneficial to wind resistance and growth.
Inverted broom shape
A tree with no branches in the middle and lower part of the trunk and multi-level or multi-level branches in the upper part. It is more common in old rubber plantations with relatively high planting density. This kind of tree is top-heavy and prone to wind folding or wind folding.
Lamp brush shape
A tree shaped like a lamp brush without branches. The trunk of some young trees is not branched from a few meters to nearly ten meters high, and the leaves at the top seem to be growing constantly, or the leaves are not obvious, and the length difference of the big petioles is very small, which looks like an inverted lamp brush or a feather duster. The tree finally branched at high places to form a broom tree.
Umbrella shape
A tree with a cluster of branches of similar size or similar size at the upper end of the trunk. This kind of tree is common in some young rubber plantations that have been unreasonably pruned. Topping on dense buds in the growing season often leads to a large number of branches at the same time, forming an umbrella tree. This umbrella-shaped branch is easy to split one by one under the action of strong wind, thus endangering the trunk and eventually destroying the whole plant.
Branch angle
The angle between the main branch and the trunk. Branching angle is one of the habits of varieties and is also related to cultivation conditions. If the branch angle is too large, the branch will wither easily; if it is too small, the branch will split easily.
Sandwich skin
Bark is sandwiched between branches and trunks or between branches. Because of the barrier of the sandwich skin, the branches that are close together cannot be connected. The smaller the branching angle, the longer the interlayer skin, and the branches that were originally close together can be separated when encountering strong wind.
Scaffolding branch
The main branches that make up the crown of a tree. Generally, it consists of primary branches (main branches) and secondary branches (main branches and big branches). The trunk branch is the skeleton of the crown and the main object of pruning and shaping, such as cultivating multi-level and multi-branch trees by pruning the trunk branch.
Overlord paper
The growth is obviously better than other branches or branches. The continuous growth of Bawangzhi often makes the center of gravity of the crown deviate, which leads to the deviation of the crown, making itself and even the whole crown prone to wind damage. It is the main object of pruning and shaping. Generally, some branches are cut off to weaken their growth and promote the balanced growth of the crown.
Pendulous branch
Branches hanging from the crown of a tree. Too low drooping branches hinder gum tapping, forest management and other operations, but help to reduce the center of gravity of the crown and improve the wind resistance. The position of drooping branches is related to variety characteristics, planting density and planting form.
secondary phloem
Phloem tissue produced by vascular cambium. The secondary phloem of rubber tree includes sieve tube, companion cell, parenchyma and laticifer. There is no essential difference from primary phloem, but cells such as laticifer are arranged regularly along the radiation direction, and the cell wall is thick.