Sometimes autumn appears before us in gray color. Gloomy leaden sky gray wall rain - it’s easy to get discouraged. But there is also a bright spot to lift your spirits! The autumn color of trees always delights and pleases the eye.
Why are the leaves green?
The green color of the leaves is due to the pigment chlorophyll. It is this substance that provides plants in the light with the synthesis of oxygen and other important substances from carbon dioxide and water. Chlorophyll is actively produced in the warm season, when trees receive enough nutrients and moisture from the soil.
The trees release the oxygen obtained through synthesis into the atmosphere, and absorb the rest of the substances themselves. With the onset of autumn, the activity of trees decreases; they receive less and less nutrition from the soil. To continue the process of photosynthesis, the foliage continues to draw nutrients from the trunk. In turn, the tree, in order to preserve reserves of substances for the winter, begins to take magnesium from the leaves, which leads to the destruction of chlorophyll. Once the green pigment begins to break down, other shades appear. Why is one leaf red, another yellow, and the third variegated, like an artist’s palette? It turns out it's a matter of chemical composition.
What determines the color of leaves
- We can see the yellow color thanks to the xanthophyll pigment.
- Carotene is responsible for the orange color.
- The leaves become crimson and red under the influence of anthocyanin. It is dissolved in the cell sap of the leaf, and the amount of pigment increases with bright light and lower temperatures.
Pigments of all these colors are always present in plant cells, but during the period of active chlorophyll production, the green color covers all the others. But a leaf becomes brown or brown when it completely loses its coloring pigments. At this time, empty cell walls that are brown in color become visible to us.
When can leaves change color?
As a rule, the color of foliage changes in the fall, because it is at this time of year that the level of plant activity decreases. It's getting colder outside, and trees are getting less nutrients from the soil. Chlorophyll begins to break down.
At the same time, its destruction occurs most actively in the light. If the weather outside is cloudy and rainy, then oaks, maples, and birches will remain green longer. If there are clear sunny days outside, the trees will change their color much faster.
During hot, dry summers, when plants lack moisture and have too much sunlight, leaves may also lose chlorophyll and their green color.
What happens to coniferous trees in autumn?
Representatives of conifers retain their green color with the onset of the cold season: spruce, pine, fir, juniper. This is because their foliage area is small and they require few nutrients to sustain life.
But even conifers lose needles, but this happens gradually. The needles are not replaced simultaneously, but in parts. 
Catch and save bright moments of autumn
Colored foliage does not last long in forests and parks, plant activity decreases and gradually fades away, they “fall asleep.” A special cork layer appears between the leaf and the trunk, and the leaf is separated from the branch. Very little time will pass, and the trees will already be completely bare.
The bright colors and beauty of autumn are fleeting. Have time to enjoy these moments and capture them in your memory. A pleasant autumn pastime is a walk through a colorful forest or park, when soft leaves of rich colors rustle under your feet. Only at this time of year can you find a special silence in the forest, when the rustling of leaves can be clearly heard. 
An unforgettable sensation will be given by a running jump into a soft pile of colorful freshly fallen leaves, the main thing is to rake up more! Both adults and children will enjoy this entertainment.
Painted in different colors the leaves look very picturesque. Collect a beautiful bouquet of dried leaves: it will last a long time and will delight you, bringing a sunny mood to your home.
From recently fallen, still succulent leaves, you can assemble a colorful album with a herbarium. Place colorful leaves between the pages of an album or book. They will soon dry, and later, after flipping through the album, you will be able to inhale the aromas of autumn. 
The creation of such an album can be turned into an interesting and educational game for children. Collect different leaves, place them between the pages, and label which tree belongs to which leaf.
Any time of year is wonderful. Autumn gives us a rainbow of colors in parks, alleys and forests. Be open to such gifts and share them with your loved ones!
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:
- Choosing the right landing site.
- Dosed and.
- Prevention from diseases and pests.
- 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:
- Lack of nitrogen. The leaves become light green, then gradually turn yellow, young shoots grow weakly.
- 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.
- Phosphorus deficiency. The plate becomes bronze or purple in color, then the leaves turn black and dry out.
- 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.
Causes and what to do when leaves turn yellow. 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 humidity soil formed as a result of excessive watering coupled with poor drainage or.
Attention! Stagnant waterlogging leads to rotting of the roots, as 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:
- Soil drainage.
- Correct choice of site level for planting or artificially increasing the level.
- Landing on shafts.
Close groundwater cause waterlogging of the soil and death of apple trees. 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 not have enough 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: 
- Hot weather.
- Pests.
- 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 later short time after landing, then the reason why the leaves of apple tree seedlings turn yellow most likely lies in the wrong choice of location 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 of the high humidity of the lower layers of the 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:
- Deficiency of iron salts, which is required for the synthesis of chlorophyll (green pigment).
- Freezing of roots after winter.
- 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 the human factor, in particular as a result of cutting a rope or wire 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.
Deficiency Dependency minerals and yellowing of leaves. 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 is 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.
Fertilizer application rates. 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, VKontakte
- - yellow – plant pigment xanthophyll
- - red - this one beautiful color appears due 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.
As soon as summer passes, restless children's voices begin to ask: “ So why do plant leaves turn yellow in the fall?»
All summer long, the trees stand proudly with bright green crowns, but when autumn comes, the sun is no longer as 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 come all other nutrients. In this way, chlorophyll feeds the plant.
But not only chlorophyll is present in green leaves, there are also other pigments
In summer, all these pigments are not noticeable, since they are hidden by a large amount 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 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
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 do green leaves change color and why do trees get rid of their leaves every year? Let's understand the details of tree life from a scientific point of view.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 the 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.
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, 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 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, trees again begin to receive energy through their roots. required quantity 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.
DID YOU KNOW...
WHY DO THE LEAVES TURN YELLOW? Green The leaves are given a special substance - chlorophyll. Chlorophyll in a living leaf is constantly destroyed and re-formed. But this only happens in the light.
In summer the sun shines for a long time. Chlorophyll is destroyed and immediately restored. Therefore, the leaf remains green all the time.
Yellow paint is always in the leaves. Only in summer yellow unnoticed. It becomes clogged with a stronger one - green.
Autumn is coming, the nights are lengthening. Plants receive less light. Chlorophyll is destroyed and does not have time to recover. The green color in the leaf decreases, and yellow becomes noticeable - the leaf turns yellow.
The foliage falls green from the alder and lilac trees. Their leaves contain no other coloring substances other than chlorophyll.
According to G. Graubin
WHY ARE THE LEAVES ON ONE ASPEN YELLOW, AND ON THE OTHER ARE RED?
It turns out that the substance that gives the leaves their red color is formed in those plants that have stored more sugar. Plants that failed to do this have yellow leaves.
WHY DO THE LEAVES FLIP FROM THE PLANTS?
In the winter cold, plant roots are almost unable to get water from the ground.
In autumn there is a lot of water, but it is cold. Therefore, plant roots cannot absorb it.
Leaves continuously evaporate water. So the plants have to shed them so as not to dry out in winter.
In winter, the leaves would only damage the plant. Piles of snow falling on them would break branches and twigs. In addition, they accumulate in the leaves during spring and summer. harmful substances. By shedding leaves, the plant is cleared of them.
How does spruce get rid of unnecessary substances?
It turns out that spruce leaves are also falling. But its leaves do not fall all at once, but little by little and constantly. New ones grow in their place. Some fall, others grow. This happens unnoticed by our eyes, and it seems to us that the spruce always has the same leaves-needles.
WHY DOESN'T THE SPRUCE LOSE LEAVES FOR THE WINTER?
The needle leaves of the spruce were small, hard, and resinous. They evaporate less water than ordinary leaves. Winter drought is not scary for spruce.
Why don't tree branches break off under the weight of snow? Because they grow obliquely downwards and spring. Snow easily slides off the branches from the slightest push, blowing wind, or from the excessive weight of wet snow. In addition, due to the waxy coating of the needles, the snow does not stick to them firmly.
WHY ARE THERE NO WOUNDS ON THE BRANCHES FROM FALLEN LEAVES?
The thing is that the leaves do not break off the branches, but fall in a strictly certain place- where the petiole is attached.
In summer, the petioles of the leaves are firmly connected to the branches. In autumn, amazing changes occur in the petioles.
In the place where the petiole is attached to the branch, a special cork layer gradually grows. It, like a partition, separates the petiole from the branch.
Now the leaf and branch are connected by several thin fibers. The weight of the leaf itself, the impact of a drop of rain, or a blow of wind is enough for the leaf to easily separate from the plant.
LEAF FALL
The earliest trees to lose their leaves are linden, birch and elm.
In linden and poplar, the leaves of the large lower branches fall off first, then the middle is exposed, and the top of the tree flies last. But in elm, hazel, and ash, leaf fall begins from the upper branches. The foliage gradually melts, revealing the dark trunk of the tree.
With the first frosts, aspen leaves fall off, then maple leaves. Only the alder and willow trees along the river banks stand thick and green until the first snow. And then the frozen, blackened, crispy leaves fall off.
According to V. Korabelnikov
