The leaves on the fruit trees in the garden turn yellow at the height of summer. The gardener understands that this is certainly an abnormal phenomenon, so he tries to find ways to restore fruit trees. In today's article we will look at why the leaves on trees turn yellow in the summer and what to do to restore them.

It will help to determine the reason why leaves on trees turn yellow in summer detailed description yellowing or symptoms of disorders and diseases:

Nutrient Imbalance

Basic nutrients necessary for tree development:

• Magnesium;
• Potassium;
• Phosphorus;

Magnesium may not be enough on sandy loam and sandy soils. Often its imbalance manifests itself in humid weather, with frequent watering - magnesium is quickly washed out.

Potassium The leaves are missing if, in addition to yellowness, a red rim is noticeable on the leaf plate. A lack of potassium is accompanied by a simultaneous lack of phosphorus.

Phosphorus fasting manifests itself in the appearance of a bronze tint and the leaves dry out, covering the entire surface of the leaf.

Feeding the soil mixture with the missing ingredients will solve the problem.

Soil waterlogging

Close occurrence of groundwater and waterlogging of the soil due to frequent watering will affect water stagnation, oxygen decomposition. The fruit trees in the garden will begin not only to turn yellow, but also to dry out and wither, it is possible that root system will rot. The problem will be solved by soil drainage, increasing the planting level, and normalizing care.

Chlorosis of fruit trees

With the development of chlorosis, the leaves of fruit trees become dull, pale, and turn yellow, as if there is no sun in the garden. Chlorosis can appear for many reasons:

• Exceeding the level of lime in the soil;
• Excessive amounts of fresh manure;
• Lack of iron salts (chlorophyll is not formed);
• Freezing of roots;
• Oxygen starvation (due to waterlogging);

If chlorosis has not managed to cover the entire crown of the tree, then it is necessary to restore the gap in care that caused chlorosis, and also feed with a solution iron sulfate (2%).

Pests and diseases of fruit trees

When aphids or mites appear, the leaves of the trees in the garden not only turn yellow in the summer, but deformed shoots appear. Similar symptoms may appear with the development of fungal diseases. In order to garden trees were healthy, it is necessary to carry out prevention by spraying with solutions before flowering and after it ends.

Damage to the bark of garden trees in summer

In summer, garden trees begin to turn yellow if their bark or root system was previously mechanically damaged. This could happen during replanting, loosening the soil, pruning or tilling. Due to disruption of the vital functions of tree tissue, general withering occurs. Identify the problem in in this case difficult. Restore fruit tree in the garden in the summer, either fertilizing or using biological drugs for covering wounds.

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?

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 leaves 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 large quantity anthocyanin in foliage.

Proposed notebook - part educational complex to 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, highlighting various signs, compare, classify, establish cause-and-effect relationships, transform information, etc.) and personal qualities 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 required quantity 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, also sheds its needles as winter approaches.

Why do leaves turn yellow and fall off in autumn?

Summer season ends with the last fallen leaves from trees and bushes. For many people, bare plants cause despondency and longing for summer. But autumn is beautiful! No wonder so many poetic lines are dedicated to this time of year. Why do the leaves of some plants turn red while others turn yellow? And why do the leaves fall?

Leaf fall is the most striking sign of autumn. These plants adapt to unfavorable seasonal conditions. Seasonal variability of plants begins with northern latitudes and gradually moves south. Leaf fall repeats itself every year and always delights us with its bright colors - from yellow and orange to pink and purple. The leaves fly away even with evergreens in the subtropics and tropics. Only there they do not fall all at once, but gradually throughout the year, and therefore it is not so noticeable.

In autumn it gets colder, and water flows into plants from the roots to the leaves at a slower pace. But it is not main reason leaf fall. Offensive unfavorable conditions is a signal for the transition of plants to a new life cycle, which is inherent in genetic code. This indicates to us that the autumn shedding of leaves is not a direct consequence of the unfavorable conditions that have occurred. It's together with in winter dormancy is included in the plant development cycle itself. There is also a way to make sure that leaf fall is a physiological process. Why does the leaf separate from the branch? It turns out that with the onset of cold weather, a cork layer forms at the base of the petiole, where the leaf is attached by a “leaf pad” to the branch. The cells of this layer have smooth walls and are easily separated from each other. As soon as the wind blows a little harder, the sheet separates from the cork layer.

The green color of leaves in summer is due to big amount chlorophyll pigment contained in them. This pigment “feeds” the plants, since it is with its help that the plant is exposed to light. carbon dioxide and water synthesizes organic substances and, first of all, the main sugar - glucose, and from it - all other nutrients. Chlorophyll contains iron, and when it breaks down, oxides are formed that have a brown-yellow color. The destruction of chlorophyll occurs more intensely in the light, that is, in sunny weather. That's why on cloudy days rainy autumn leaves retain their green color longer. When it comes in autumn sunny days the leaves acquire golden-red colors.

However, along with chlorophyll, green leaves also contain other pigments - yellow xanthophyll and orange carotene (it determines the color of carrot roots). In summer, these pigments are invisible, as they are masked by a large amount of chlorophyll. In autumn, as vital activity in the leaf fades, chlorophyll is gradually destroyed. This is where the yellow and red shades of xanthophyll and carotene appear in the leaf.

In addition to gold, the autumn colors of trees contain crimson shades. This color comes from a pigment called anthocyanin. Unlike chlorophyll, anthocyanin is not associated inside the cell with plastic formations (grains), but is dissolved in cell sap. When the temperature decreases, as well as in bright light, the amount of anthocyanin in the cell sap increases. In addition, stopping or delaying nutrient synthesis in foliage also stimulates anthocyanin synthesis.

Fallen leaves can retain their shape and color for a few more days, and then they begin to dry out and acquire a brown color that is not very pleasant to the eye. Some of the leaves remain in place under the trees and shrubs, while some are carried away by the wind outside the site. For aesthetic reasons, a gardener is often tempted to clear the soil of fallen leaves. Is it necessary? After all, the leaves contain the same chemical compounds that were taken by plants from the soil. True, they acquired a slightly different chemical composition and entered into plant-derived organic matter. Once on the soil surface, the leaves become “prey” for a great variety of different living organisms. Among them, earthworms play the most important role in leaf utilization. The products of their vital activity (the excrement of worms are called caprolites) contain the entire set of nutrients for plants in almost finished form. So the leaves, having entered the biological cycle of substances, returned to the soil what they once received in the plant.

Now decide for yourself - to remove leaves from under the trees or not? There are two ways to save useful properties fallen leaves. The first is to leave it in place until spring, followed by digging. At the same time, the leaves will insulate upper layer soil. The second path will be somewhat more difficult and take longer. Collect leaves in compost pit and after a year or two return it under the trees in a rotted form.

V. A. Rassypnov , professor of ASAU

It has long been proven that plants are living beings. They, just like animals, eat, breathe, and reproduce. Thousands of biological events occur in them chemical reactions, useful nutrients are formed, and breakdown products are removed from them as a result of metabolism. That is, all the processes that characterize the manifestation of life are also present in plants, making our planet unimaginably beautiful, pure and diverse.

Biological rhythms

How do plants respire? Why do their leaves turn yellow? What do they eat? How do they grow? Many questions arise for those who see these amazing creatures, so diverse, beautiful, bright and colorful.

All plants have certain characteristics, just like other living organisms. These include:

• opening and closing of buds under the influence of length and chemical composition environment;
• intensive increase in shoot mass;
• contraction and opening of stomata on leaves;
• increased or decreased respiration, photosynthesis;
• leaf fall and others.

Thus, the answer to the question of why plant leaves turn yellow lies in the mechanisms of biological rhythms. It is these processes that allow them to adapt to environmental conditions, survive in them, carry out life activities as efficiently as possible, grow and develop, respond to chemical and physical influences from nature, humans, animals, and so on.

Why do leaves on trees turn yellow, for example? This is also one of the manifestations of a biological rhythm aimed at preserving the viability of an individual in conditions low temperatures and reducing the number sunlight and moisture. The color of the leaf blade is determined by special substances in its composition.

Why do the leaves turn yellow and fall off? Yes, because there is a restructuring of chemical reactions inside the plant organism. Each representative of the flora contains a number of pigments - substances that determine the color of organs (leaves, flower corollas, stems, and so on). In total, four main groups of such compounds can be distinguished:

All of the pigments listed primarily provide an external reaction to changes in the state of individuals. Let’s take a closer look at why plant leaves turn yellow and what causes such manifestations.

Causes of leaf fall in trees

The phenomenon of leaf fall is one of the most beautiful in nature. That is why autumn is the favorite season of many poets. After all, the surrounding beauty simply cannot help but become a source of inspiration for creative people. The multicolored colors all around, yellow, green, red, orange and even brown-violet shades are simply dizzying, and the smell of fallen leaves pleasantly pleases the sense of smell.

What causes such changes and is this always normal? Let's consider the reasons for leaf fall in trees. They can be combined into two groups: natural and forced. Each includes a number of points and explanations for them.

Natural

These reasons include seasonal changes weather conditions, as well as changes in the length of daylight hours. All summer long, the green giants prepare for these rhythmic changes. They accumulate nutrients and store them in the stems and trunk, actively carry out the processes of photosynthesis and respiration, and consume the maximum possible amount of moisture.

With the onset of cold weather and shortened daylight hours, transformations begin inside the leaf blades.

1. The chlorophyll pigment begins to act less and less, the color fades. This gives the opportunity for other pigments to appear. As a result, the leaves turn yellow, red, and so on. What color the falling leaves will be depends on the genetic characteristics of the tree species. Moreover, an interesting fact is that what the sun is brighter V autumn time, the faster chlorophyll is destroyed and the leaves turn yellow. During prolonged rains, trees remain green for longer.
2. During summer period many metabolic products, salts, minerals. This makes the leaf heavy, and it gradually begins to peel off in the petiole area from the stem.
3. At the base of the petiole, between it and the trunk, the processes of formation of a special tissue layer begin, which gradually rejects the leaf.
4. Under the influence of mechanical factors (rain, wind, thunderstorm, etc.) and their own gravity, all the leaves begin to fall one by one.

Forced

There is another answer to the question of why the leaves turn yellow. This happens for forced reasons, such as:

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 imbalance soil nutrition. 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 the excess soil moisture resulting from overwatering 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 old ones, which are more often susceptible to yellowing of the foliage due to fungal infections. An actively growing tree may lack nitrogen.
• If not the entire apple tree turns yellow, but only individual branches with the formation of a 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 they appear in the spring yellow leaves on an apple tree, the cause is scab or brown spot. Young leaves immediately turn yellow and become spotted.

Need to rake fallen leaves and burn them, then spray the tree 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 the human factor, in particular as a result of cutting a rope or wire into the bark.

Everything needs to be cleaned up extra elements, for example, a label on a 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.

A serious problem that threatens life - 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 specifically on 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,
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