Thickening Of The Tree Trunk. Diseases And Pests. Garden Care. A Photo

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Thickening Of The Tree Trunk. Diseases And Pests. Garden Care. A Photo
Thickening Of The Tree Trunk. Diseases And Pests. Garden Care. A Photo

Video: Thickening Of The Tree Trunk. Diseases And Pests. Garden Care. A Photo

Video: Thickening Of The Tree Trunk. Diseases And Pests. Garden Care. A Photo
Video: How To Protect Trees From Wood Boring Insects 2024, March
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Not infrequently, noticeable thickenings appear in the lower part of the trunks. Some argue that this is an indicator of the good condition of the tree, while others consider them a dangerous sign. But what in reality?

Good or bad for a tree depends on the cause of the thickening, its specific place on the trunk and the anatomical structure of the tissues. Let's start with a favorable reason.

If the thickening is in the lower part of the trunk, starts from the ground and is not one-sided, like a flux, but uniform in diameter, there is no reason for concern. This is an indicator of a healthy structure of a tree, its good architectonics. After all, the foundation of any structure is always wider than the top. And the fruit tree in this situation can also be considered as a structure consisting of a rootstock and a scion. It is not without reason that IV Michurin called the rootstock "the foundation of a fruit tree." Look at what a thickened "foundation" Melba of venerable age has. The tree firmly "sits" on it, as if on a "pedestal".

Thickening of the trunk
Thickening of the trunk

© photofarmer

Let me remind you that the stock is not only the root system, but also the lower part of the trunk to the graft site, which can be at different heights from the roots (a high graft is clearly visible on the beveled scar on the bark). And the scion is the main above-ground part of the tree that grew out of grafting.

The rootstock is always at least a year or two older than the scion, since when growing seedlings, grafting or budding is done at least in a one-two-year-old wild-stock, therefore its wider part at the base of the tree is quite natural "in seniority".

Of course, this explanation is true with the general good condition of the tree: normal growth, healthy dark green leaves, winter hardiness and yield characteristic of the variety, timely passage of all phases of vegetative development, etc.

Thickening of the trunk
Thickening of the trunk

But if there is a thickening “on the contrary”, which violates the natural structure of the tree, when either a one-sided “gumboil” or a noticeable influx of scion over the rootstock is formed, these are already other situations that require specific consideration.

Sometimes "thick top-thin bottom" occurs due to the stronger development energy of the scion compared to the stock. Such a feature is possessed, for example, by the early-growing apple variety Beforest. Its grafts grow and develop so rapidly that they often catch up and surpass the thickness of the stock. Fortunately, already in the 2nd or 3rd year, Beforest begins to bear fruit, and this "overtaking" stops.

A more vigorous development occurs in cherries grafted onto cherries. The vegetative mass of the cherry with its large leaves on powerful shoots causes, accordingly, a rapid growth in thickness, outstripping the less vigorous growth of the cherry rootstock.

It is known from classical literature that some trees with thickenings “on the contrary” can live and bear fruit normally for many years. For example, in the monograph of a specialist at the East Malling Experimental Station (England) R. Garner "Guidelines for grafting fruit crops" (Moscow, 1962), a photograph of a 55-year-old cherry tree with a strong thickening at the site of grafting is given. The tree, according to the author's testimony, was quite healthy and fruitful.

Thickening of the trunk
Thickening of the trunk

© jmcextman

But this is rather an exception to the rule, and it is better not to allow such anomalous development. Furrowing will help smooth out the beginning difference in thickness - longitudinal cuts of the bark with a small (1 mm) notch and wood. They are made in May-June with the sharp tip of a knife along the entire circumference of the trunk from the point of thickening to the ground. The distance between the cuts is 5-10 cm, the older the tree, the more often the grooves are made. This technique stimulates the growth of wood and bark tissue, contributing to the leveling of the thickness of the rootstock and scion.

But usually thickening in the form of slugs from above is an unfavorable sign that occurs in cases of physiological incompatibility of the scion with the stock, leading to the death of trees. This phenomenon itself consists in poor anatomical fusion and weak interpenetration of tissues and vessels of the grafting components. The consequence of incompatibility is insufficient mechanical strength at the place of their junction, as well as carbohydrate starvation of the roots, since they do not receive plastic substances produced by leaves during photosynthesis. Having a large molecular structure, they cannot penetrate to the roots due to the poor vascular relationship between the scion and the stock. As a result, these substances are retained from above, gradually forming a noticeable influx in the form of a tumor above the inoculation site.

Thickening of the trunk
Thickening of the trunk

© nellylouise1

Most often, such incompatibility occurs in unrelated vaccinations, when, for example, a pear is grafted onto an apple or mountain ash, chokeberry, irga, etc. In the early years, their "union" may seem normal: everything grows and even bears fruit. In fact, it turns out to be short-lived, such plants die due to drying out, breaking off in a strong wind or under the weight of the harvest, reduced winter hardiness, etc.

In addition to influxes, physiological incompatibility has other accompanying diagnostic signs: abundant budding of flower buds with weak growths; fruits that are too small for a given variety and their strong crumbling; general depression despite good care; premature coloring of leaves in the scion and the appearance of shoots from the rootstock.

Sometimes physiological incompatibility does not appear immediately, it has a kind of delayed character. But if the tree, despite good care, gradually takes on a depressed appearance and at the same time the influx from above increases, it will be short-lived.

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