Why do the leaves turn yellow? Why do the leaves turn yellow?

It has long been proven that plants are living things. They, as well as animals, feed, breathe, reproduce. Thousands of biochemical reactions occur in them, useful nutrients are formed, from which the decay products are derived as a result of metabolism. That is, all the processes that characterize the manifestation of life are present in plants that make our planet unimaginably beautiful, clean and diverse.

Biological rhythms

How do plants breathe? Why do the leaves turn yellow? What do they eat? How to grow? A lot of questions arise in those who see these amazing creatures, so diverse, beautiful, bright and colorful.

For all plants, certain biological rhythms are characteristic , as well as for other living organisms. To them it is possible to carry:

• Opening of buds and their closure under the influence of the length of daylight and the chemical composition of the environment;
• Intensive escalating mass;
• Compression and opening of stomata on leaves;
• Increased or decreased breathing, photosynthesis;
• Leaf fall and others.

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

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

Pigment of plants contained in leaves

Why do the leaves turn yellow? Yes, because there is a reorganization of chemical reactions within the plant organism. Each representative of the flora contains a number of pigments - substances that determine the coloring of organs (leaves, flowers, stems, etc.). There are four main groups of such connections:

1. Chlorophyll . Pigment containing in its structure a cation of magnesium and several porphyrin rings. It gives the plants and its parts a rich green color, takes an active part in the processes of photosynthesis. It is under its influence that plants transform light into solar energy into the energy of chemical bonds. So the reserve nutrient is formed - starch. Under favorable conditions in evergreen plants, chlorophyll is in the overwhelming majority, therefore other pigments do not appear.
2. Xanthophyll . This compound is found in all individuals, but does not appear under favorable conditions, as it is suppressed by chlorophyll. In many algae in the flowers' crowns, in the stems, this pigment manifests itself, forming a yellow color.
3. Carotenoid . The orange color of the leaves, parts of the shoot, the flower haloes is determined precisely by this connection. It is often suppressed by chlorophyll and manifests itself only at the onset of low temperatures, unfavorable environmental conditions.
4. Anthocyanins are pigments that cause the formation of beautiful red shades in plant parts. Just like the previous two, it manifests itself in a natural form only in the corolla of flowers or algae (red algae). The change in conditions and the destruction of the porphyrin rings of chlorophyll causes a stronger effect of anthocyanins.

All these pigments primarily give an external reaction to the change in the state of individuals. Why the plants turn yellow leaves, which causes such manifestations, we will consider in more detail.

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 can not but become a source of inspiration for creative people. Many colors around, yellow, green, red, orange and even brownish-violet shades just turn their heads, and the smell of fallen leaves pleasantly pleases the sense of smell.

What are the reasons for such changes and is it always normal? Consider the causes of 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

For such reasons include the seasonal change of weather conditions, as well as changes in the length of daylight hours. All summer, the green giants are preparing for these rhythmic changes. Accumulate nutrients and store them in stems and trunk, actively carry out photosynthetic and respiratory processes, consume the maximum possible amount of moisture.

With the onset of cold weather, shortened light days inside the leaf plates, transformations begin.

1. Pigment chlorophyll begins to act less and less, the color turns pale. This gives an opportunity to manifest themselves to other pigments. As a result, the leaves turn yellow, turn red and so on. What will be the color of the falling leaves depends on the genetic characteristics of the tree species. And the fact is interesting that the brighter the sun in the autumn season, the faster chlorophyll breaks down, and the leaves turn yellow. During prolonged rains, the trees delight the greenery longer.
2. During the summer period, many metabolic products, salts, and mineral substances accumulate in the plates of sheets. This makes the sheet heavy, and it gradually begins to peel off around the stalk 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 to gradually tear off the leaf.
4. Under the influence of mechanical factors (rain, wind, thunder, etc.), of its own severity, all leaves begin to fall alternately.

Forced

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

• Sharp temperature fluctuations;
• Lack of mineral nutrition;
• Lack of sufficient moisture or excess;
• Hard exposure to direct sunlight;
• Vital activity of parasites.

These reasons lead to a decrease in the viability of trees. That's why the leaves turn yellow.

Houseplants

Many growers also have a question: "Why do flowers have yellow leaves?" Often you can see the drooping parts of plants, their unhealthy, faded appearance, and this applies not only to flowering species, but also ferns, rarely flowering plants and succulents. With what it is connected, let's try to figure it out.

Causes of yellowing

Why do the leaves turn yellow?

1. Excessive or insufficient watering.
2. Too bright sun or its lack.
3. Lack of potassium, magnesium and other minerals.
4. Defeat parts of the shoot or the roots of pests.
5. Excess of dust, fungi and bacteria.

These are the most common causes of yellowing of leaves in plants.

Methods of eliminating the phenomenon

Before taking action, you need to determine the specific reason why the flower yellow leaves. To do this, study materials for the care of each particular plant, because to any of them requires an individual approach.

Further, it is necessary to limit the limiting factor of development: if it is insufficient watering - to increase it, if excess - to reduce, protect from the sun or add it, feed up with mineral fertilizers, but do not overdo it. The main thing is to remember that flowers like cleanliness. Therefore, they must be protected from dust, debris and pollution.