The untimely loss of green color from the leaves of an apple tree worries any gardener, and rightly so! The tree is clearly in poor condition and may die.

Due to ignorance of the reasons, the gardener may make a mistake in trying to solve the problem, which will lead to the loss of precious time to save the tree. It is also important to know how to prevent such problems from occurring.

So as not to wonder why the leaves of an apple tree turn yellow, it is important to observe:

1. Choosing the right landing site.
2. Dosed and.
3. Prevention from diseases and pests.
4. Autumn work to protect the tree from winter damage.

Important! The leaves on the apple tree turn yellow in different ways. For example, from bottom to top or top to bottom, the shade changes, the color change occurs along with curling or falling.

Based on the nuances, you can determine the reason why the leaves on the apple tree turn yellow.

Why do the leaves turn yellow?

Change in foliage color starting from the lower tiers of the tree– indicator of soil nutrition imbalance. So why do apple tree leaves turn yellow in summer? The reason may be a lack of nitrogen, phosphorus or potassium:

1. Lack of nitrogen. The leaves become light green, then gradually turn yellow, young shoots grow weakly.
2. Lack of potassium. A red rim appears on the border and dries up. When potassium is deficient, trees cannot effectively absorb nitrogen from the soil, so symptoms of the problem often appear in tandem.
3. Phosphorus deficiency. The plate becomes bronze or purple in color, then the leaves turn black and dry out.
4. Magnesium deficiency occurs more often on sandy soil and sandy loam, especially in the event of prolonged rains. Yellow, red, and then brown spots appear on the leaves (spotting as a result of scab development looks different), fruits and leaves drop off.

Elimination of the above problems is achieved through the timely introduction of nutrients into the soil and proper.

If yellowing of leaves started from the top of the apple tree, then you need to pay attention to excess soil moisture resulting from excessive watering coupled with poor drainage or.

Attention! Stagnant waterlogging leads to rotting of the roots, since toxic products of anaerobic decomposition accumulate in the thickness of the damp soil.

It is better not to allow such a situation, since it is quite difficult to correct it.

It is necessary to organize:

1. Soil drainage.
2. Correct choice of site level for planting or artificially increasing the level.
3. Landing on shafts.

Yellowing of a young apple tree

The main reasons why leaves of a young apple tree turn yellow:

• If the groundwater is shallow, then a three-year-old young apple tree may begin to turn yellow (such cases are not uncommon).
• Young apple trees are not typically affected by fungus, unlike older ones, which are more often susceptible to yellowing of the foliage due to fungal infections. An actively growing tree may lack nitrogen.
• If the entire apple tree does not turn yellow, but only individual branches with the formation brown edge near the leaf (marginal burn), then it is necessary to apply potash fertilizer.
• At deficiency of sulfur and nitrogen The color changes of young leaves are similar, so you need to fertilize with complex mineral fertilizer.

Other reasons why young apple trees turn yellow:

1. Hot weather.
2. Pests.
3. Less commonly, fungal diseases.

Presence of spots on leaves - sign of scab or brown spot. Typically, scab damage is noticeable already in the spring. Oily spots appear on the leaves, then a velvety coating appears and the plate turns brown and dries out.

For a young tree use Bordeaux mixture; the drugs Skor or Fitosporin are also suitable.

To increase vitality the affected specimen is fed with nitroammophoska, the box is dissolved in 10 liters of water.

First, water the tree generously with several buckets of water, then add 2-3 liters of the prepared solution.

Watch the video about a disease such as scab:

Yellowing of seedlings

If this happened shortly after landing, then the reason why the leaves of apple tree seedlings turn yellow most likely lies in wrong choice place or deepening of the specimen.

In the first case, the development of the root system is hampered by a lack of oxygen, which arose as a result high humidity lower layers of soil.

Exceeding the planting depth by 10-15 cm, It is also a common reason why the leaves on an apple tree turn yellow.

Another reason for the yellowing of the foliage of a seedling is unsuitable soil composition eg as a result of high (alkaline) pH due to excess lime or fresh manure.

The leaves turn pale yellow and then fall off.

The disease is called chlorosis, other causes of which include:

1. Deficiency of iron salts, which is required for the synthesis of chlorophyll (green pigment).
2. Freezing of roots after winter.
3. Oxygen deficiency in the soil as a result of waterlogging.

in spring

If yellow leaves appear on an apple tree in spring, the cause is scab or brown spot. Young leaves immediately turn yellow and become covered with spots.

Need to rake fallen leaves and burn them, then spray the tree with Bordeaux mixture. Sometimes rapid spring yellowing of leaves occurs as a result of a severe deficiency or excess of microelements.

Summer (July-August)

Yellowing of leaves on an apple tree in summer is often associated with physiological disorders of the tree. For example, too severe planting depth or winter freezing of the tree trunk.

Often, disturbances in the physiological functioning of plant tissues arise due to human factor, in particular as a result of a rope or wire cutting into the bark.

It is necessary to remove all unnecessary elements, for example, the label of the seedling and its fastening.

ATTENTION: Common mistake– untimely loosening of the grafting strap.

The growth of the trunk in width leads to cutting. Minor damage is corrected by furrowing, that is, making cuts in the bark down to the wood at the damage, above and below it, to generate the formation of callus influxes.

Another reason why an apple tree turns yellow in summer is physiological incompatibility of scion and rootstock as a result of poor fusion of grafted surfaces.

Brief description of special cases

Young apple tree and seedling

Main reasons:

• Wrong landing
• Unsuitable soil composition,
• Waterlogged soil
• Infection with fungal diseases,
• Freezing of roots in winter.

Often the change in color of leaf blades from green to yellow is associated with the cause magnesium deficiency, boron, as well as potassium and phosphorus.

Deficiency of these elements causes death of shoot ends.

ADVICE: A sufficient concentration of nitrogen is indicated by the presence of nettle as a weed. The presence of dandelion, on the contrary, indicates a shortage.

On one branch

Yellowing foliage on one branch may indicate aphid infestation of part of the tree.

Other reasons: damage to roots by mice or moles.

Many of the above options (freezing of roots, deficiency of elements) can lead to yellowing of not the entire tree.

Serious problem, life-threatening – bark diseases, for example, cytosporosis. The lesion first covers one branch, then spreads more strongly and finally to the entire tree.

Leaves turn yellow and dry out

The reason lies in the development of fungal diseases or sucking insects, in particular. It is better to prevent such problems than to solve them as they arise.

Leaves curl and fall

As a result of feeding, it sucks juices from the leaves, as a result of which the foliage curls and falls off. This coincides with the curvature of young shoots.

Aphids accumulate at the ends of branches, which is where it is necessary to treat them more intensively with Confidor or Iskra, and from folk remedies will do decoction of wormwood or garlic.

The leaves are turning pale

The chlorosis described above usually occurs in early summer. Leaves with this disease can become almost white.

If chlorosis is mild, spraying with 2% iron sulfate will help.

If chlorosis occurs as a result of excess lime, then the site may be completely unsuitable for growing garden trees.

ADVICE: It is necessary to assess the condition of weeds (dandelion, bindweed, yarrow, etc.) in order to determine the cause of chlorosis of the apple tree. If the grasses are pale in color, then to normalize the soil, alfalfa is planted as green manure; rotted manure or ammonium sulfate/nitrate are also added to the soil (alkaline fertilizers are not suitable, only fertilizers with an acidic reaction).

What to do if a columnar apple tree turns yellow?

Wilting of newly emerged leaves is the result of poor root nutrition, for example, due to damage to underground parts by rodents.

It is necessary to carry out hilling to stimulate the growth of adventitious roots.

This method works exactly for dwarf varieties, since the low-growing crown of young specimens requires less nutrition.

At the Kras apple tree in Sverdlovsk

The falling of leaves in the Krasa Sverdlovsk variety, like in all apple trees, may be a consequence of the development powdery mildew.

Gardeners, when growing this variety of apple trees, note yellowing of the foliage when high temperature and humidity.

ATTENTION: The variety responds well to potassium fertilizing.

Do not add ash or lime in excess, since their high concentration can cause sulfur and iron deficiency.

If these substances are added in the wrong concentration, ammonium sulfate or ammonium nitrate should be added to eliminate negative influence, you can additionally feed with sources of iron and sulfur.

Incompatibility may occur when unrelated trees are used. For example, an attempt to graft an apple cutting onto a pear tree.

Instances with incompatibility may develop and bear fruit for some time.

May be observed:

• Yellowing of leaves
• The formation of small (uncharacteristic for the variety) fruits and their severe shedding,
• Decreased cold resistance
• The presence of thickenings at the grafting site,
In contact with

As soon as summer passes, restless children's voices begin to ask: “ So why do plant leaves turn yellow in the fall?»

All summer, the trees stand proudly with bright green crowns, but when autumn comes, the sun is no longer so warm, the sky is increasingly cloudy and drizzling - that’s when the plants begin to change color. Their leaves turn red, yellow, and orange - and the autumn forest begins to seem like a special magical place.

In summer, the foliage of trees contains a lot of the pigment chlorophyll, which is what colors the leaves green. This pigment is vital for any tree - with the help of chlorophyll, in the light the plant synthesizes sugar - glucose - from carbon dioxide and water. And from this sugar - all the rest nutrients. In this way, chlorophyll feeds the plant.

But not only chlorophyll is present in green leaves, there are also other pigments

• - yellow – plant pigment xanthophyll
• – red – this beautiful color is manifested thanks to pigments anthocyanins
• - orange - pigment carotene, the same pigment is found in large quantities in carrots, which is why carrots have such a bright orange color.

In summer, all these pigments are not noticeable, since they are hidden a large number of green chlorophyll. But in the fall, vital activity in the leaves fades, and chlorophyll gradually begins to collapse. This is where all the other “color” pigments begin to appear - thus In autumn, plant leaves turn yellow and fall off.



The sunnier the weather in autumn, the faster chlorophyll is destroyed in plants. And in a cloudy, rainy autumn, the leaves on the trees remain green longer. But if, after prolonged rains, sunny weather quickly sets in, or as this time is also called “Indian summer,” then the green color of the leaves changes to golden-red tones in 1-2 days.

Red pigment – anthocyanin– unlike chlorophyll, it is not associated with plastic formations, but is dissolved in cell sap. When the temperature drops, there is much more anthocyanin in the cell sap. Therefore, the red color of trees in autumn indicates the extinction of leaf activity - the foliage is preparing to fall.

Line UMK V.V. Pasechnik. Biology (5-9)

Biology

The world

Why do the leaves on trees turn yellow and fall off in the fall?

With the arrival of autumn appearance trees are changing. The dense green crowns are replaced by bright crimson-red “caps” of leaves, which then completely fall off. Why green leaves change their color, and why do trees get rid of their leaves every year? We understand the details of the life of trees with scientific point vision.

Leaves the color of summer

A special substance is responsible for the emerald foliage of any plant chlorophyll- a pigment that gives leaves a green color. It not only provides fresh herbal color, but also nourishes plants by participating in the formation of glucose and other nutrients.

This pigment is produced through the process of photosynthesis. Leaves absorb carbon and release oxygen. This happens in comfortable conditions- in the presence of heat and sun. In addition to oxygen, photosynthesis also produces the chlorophyll we know.

With the onset of the cold season, sunny days become shorter: the weather is no longer pleasant with warmth, and there is less light. Chlorophyll ceases to be actively produced and is replaced by other pigments.

Every Hunter Wants to Know

The autumn colors of the foliage are due to special pigment substances. Carotene is responsible for Orange color. This pigment can be found not only on the autumn crowns of trees, but also in ordinary carrots. Yellow leaves appear due to xanthophyll, and red ones due to anthocyanin.

The conditions for the production of pigments are different. If chlorophyll needs a lot of heat and sun, then xanthophyll and carotene need enough heat and a little light. But to get a lot of purple leaves, you need cold weather and bright sun. Frost and plenty of light are the conditions for the appearance of large amounts of anthocyanin in the foliage.

The proposed notebook is part of the educational complex for the textbook by A. A. Pleshakov, N. I. Sonin “Biology. Introduction to biology. 5th grade." Special signs mark tasks aimed at developing meta-subject skills (planning activities, identifying various features, comparing, classifying, establishing cause-and-effect relationships, transforming information, etc.) and personal qualities of students. The material in the notebook is arranged in the same sequence as in the textbook.

Yellow leaves swirl over the city

In autumn, trees make us happy at first bright colors, but with the approach of winter they begin to get rid of leaves. Why and why does this happen?

With the arrival of the cold season, the soil begins to freeze. Trees stop receiving the required amount of moisture and nutrients. Life processes begin to stop, plants go into hibernation. In order not to waste energy on nutrition, plants are forced to get rid of excess load - and shed their leaves.

At the base of the petiole (the narrow part of the leaf, the place where the leaf blade is attached to the stem), a special separating cork layer is formed, blocking the “delivery” of nutrients from the tree. It becomes increasingly difficult for weakened leaves to stay on the branches and gradually they begin to fall off. As with the appearance of a multi-colored crown, so with the fall of leaves, all processes do not occur instantly. That is why at first we see a measured change in the colors of the foliage, and then the trees slowly get rid of their bright attire.

Leaf fall is a prerequisite for the existence of trees, helping them renew their foliage annually. With the arrival of spring, the trees again begin to receive required amount water from the thawed soil and revive their lush crown.

But also among coniferous trees there are exceptions, for example, larch. It grows in harsh conditions and cannot evaporate moisture in winter. Therefore, like deciduous trees, they also shed their needles as winter approaches.

Have you ever wondered why autumn is golden? Why do leaves turn yellow in the first place? Let's try to understand this issue and tell you.

Pigments are responsible for the color of any plant. For example, the red color of an apple is due to anthocyanin, the green color of a cactus is due to chlorophyll, orange carrots- carotene. The yellow color comes from xanthophyll. Anthocyanin, carotene and xanthophyll are carotenoids. They give color to the leaves.

But how does this happen? Why do they appear in the leaves in the fall? After all, in the summer we see green tree crowns.

It turns out that the whole problem is chlorophyll. The amount of carotenoids does not increase, but chlorophyll decreases. With the onset of cool weather, trees switch to energy saving mode.

In the summer, when there is a lot of sun, green leaves filled with chlorophyll absorb light and convert it into chemical processes beneficial to the plant. Photosynthesis occurs. As you can imagine, in the fall the daylight hours become significantly shorter. But the leaves have chlorophyll, and they really want the sun. And there is not enough of it. At such moments, the crown “sits on the neck”, sits on the neck of the tree and begins to draw out all the useful substances from it. Then the tree decides: that’s it, hair, I can’t afford you! I won't give you magnesium. Because of this, the leaves fall off. And the tree trunk calmly survives the cold, and then again acquires a crown.



But before that, due to the reduction in the amount of chlorophyll in them, they will turn yellow. After all, carotenoids will predominate.

By the way, it is interesting that those leaves that have fallen and turned brown no longer contain any pigment at all.



However, why, for example, does the Christmas tree not turn yellow and shed its leaves? In fact, conifers shed needles, but not in such quantities. In addition, it’s all about the peculiarities of the structure of the needles. Each needle is encased in a protective wax sheath. There is also more than enough chlorophyll there. But the area of ​​the needles less area leaves, so the trees survive the cold quite calmly.

Yes, such interesting chemical processes are happening around us. But we don't always notice it.



Did you know about this feature of trees? Tell us in the comments!

Adults, immersed in everyday problems, stop paying attention to the world, while children are amazed by its features every day. How does it work? And why? What for? Is that necessary? What interests these little whys! And if you bear the proud title of mom or dad, then sooner or later you will definitely hear the question: “Why do the leaves turn yellow in the fall?” It seems that the question itself is not very complicated, this is one of the questions, but it will certainly entail a number of additional ones that need to be answered in detail and clearly. Well, let's try to do this!

Why do the leaves turn yellow?

In spring and summer, each leaf contains the pigment chlorophyll, which is green in color. It is the large amount of chlorophyll that makes the leaves on trees green. This pigment is needed by a tree not just for beauty, but for tasty nutrition, since chlorophyll can transform with the help of daylight carbon dioxide and water into nutrients. So, thanks to its spring-summer green color, the tree grows and develops. But the season comes when nature prepares for winter, when its vital activity stops, when the leaves turn yellow - this happens in the fall. Less and less water enters the leaves, chlorophyll is gradually destroyed, and the plants lose their green color. An interesting fact is that chlorophyll is more actively destroyed under the influence of the sun, so the period when leaves begin to turn yellow in the fall does not always occur at the same time. In dry, clear autumn, the leaves change color faster, and in rainy autumn they remain green for a long time.

Why are these yellow and those red?

An attentive child will definitely ask why some leaves on trees turn yellow, others turn red, and others even turn brown. The answer is quite simple. The fact is that in addition to chlorophyll, plant leaves also contain other pigments, but due to the predominant green color, they are simply not visible. As the green chlorophyll recedes, other colors become visible:

• yellow leaves get their color as a result of the “work” of the plant pigment xanthophyll;
• orange leaves put on their autumn attire when the carotene pigment becomes visible, which, by the way, is familiar to everyone from the bright orange color of carrots;
• red leaves acquire this unexpected color thanks to anthocyanin pigments;
• brown leaves- this is no longer the color of pigments, but the color of the cell walls of the leaf; it appears when other visible coloring pigments are absent.
And why do the leaves fall?

If we talk about the process of leaf falling itself, the mechanism is quite clear - in the fall, when the leaves of plants turn yellow, a thin separating layer of cells, the so-called cork layer, appears at the base of the leaf. Gradually, this partition breaks the connection between the tree and the leaf. All you have to do is wait for the wind to blow and the leaf ends up on the ground. A small scar remains on the branch where the leaf is torn off, which is covered with a protective cork layer, which means that this is a completely painless period for the tree. If you wonder why the leaves turn yellow and fall off, in a global sense, then we can understand that this is defense mechanism, which nature came up with for the survival of trees in the cold season. All plants receive most of their nutrition from water that comes from the soil, but in winter the water freezes. That is, if the leaves remained on the trees, they would need to eat, but the frozen water could not bring the necessary nutrition with it, so the leaves would pull substances from the roots, trunk and branches. Most likely, having lost its vitality, the tree organism would die. So the falling of leaves is an opportunity to withstand the winter and bloom again in the spring.