What can be cooked from squid: quick and tasty

Pliny wrote in his Natural History that trees grow at different rates: “Some trees by nature grow slowly, and above all those that are born only from seeds, and are distinguished by longevity. Those that die quickly, grow quickly, such as the fig and pomegranate trees, plum, apple, pear, myrtle, willow. "
Most plants grow at a rate of 0.005 millimeters per minute, which is about 0.7 centimeters per day. The growth rate of the hyacinth flower-bearing arrow often exceeds three centimeters per day. Such an explosion of growth is possible due to the intensive use of the accumulated in the bulbs during the flowering period. nutrients.
In Myanmar (formerly Burma), a representative of the legume family Amherstia nobilis (Amherstia nobilis) grows - one of the most ornamental plants the world, called the "queen flowering trees". Against the background of its dark green foliage, large 30-centimeter inflorescences, consisting of two dozen bright large flowers, look very beautiful. Due to its high decorativeness, Amherstia is often cultivated in the tropics. Its leaves reach a meter in length in just a few days.
Bamboo is growing even faster. So, for example, the shoots of this plant increase in a minute by 0.6 millimeters, in an hour - by 3.6 centimeters, in a day - by 86.4. It so happens that in one night for empty space a young bamboo grove appears, knee-high. An anecdotal incident happened to a certain hunter who camped in bamboo plantings for the night. Before going to bed, he hung his hat on a nearby plant, and in the morning he could not get it. Konstantin Paustovsky wrote in his story "Throw to the South":
“Bamboo shoots broke through the pavements. In one night, they stretched a meter, or even more. "
Why is there such a significant difference in growth rates between individual plant species? Maybe in fast-growing individuals, cells divide more intensively? It turned out that this is not the case (as a rule, within a day, each cell of the growth zone doubles in both fast-growing and slow-growing species), but in the unusually long length of the growth zone. For example, in slow-growing plants, only the tip of the stem, only 0.6 centimeters long, is involved in growth, while in bamboo, sometimes a 60-centimeter section of the stem is involved.

It should be clarified that in bamboo, like in all other cereals, the growth site is not located in one place, but in the lower part of each internode. Thanks to this, the stem of the plant reaches its final size (30 meters) in a few months, while many trees would take several decades to achieve the same goal.
Eucalyptus grows very quickly. For seven years, his seed turns into a tree 19 meters high and a trunk circumference of 1.5 meters. The height of these giants was discussed in the section "Do plants evaporate a lot of water?"

Another representative of fast-growing trees is crescent albicia from the mimosa family (Albizzia

falcataria). Its closest relative, the Moluccan albition (A. moluccana), reaches a height of five to six meters in just a year, and at the age of six years - 25 meters with a trunk thickness at the level of human growth of 20-25 centimeters.
The real record holder in terms of growth rates is the dictyophore mushroom, which we talked about in the “Forest and Sea Lights” section.
To monitor the growth rate of plants, special devices are usually used - auxanometers. The simplest auxanometer is a sturdy straw attached to a vertically oriented board. The pin serves as an axis around which it pivots. The long end of the straw moves along the scale drawn on the paper, and the short end is fixed at the top. fast growing plant with a soft thread. If the room is warm enough and the soil is well moistened, then after a while you can see that the straw moves along the scale, and this indicates the presence of growth.
Scientists are using more advanced auxanometers to measure plant growth over a short period of time. Especially sensitive devices were designed by the Indian plant physiologist Jagdish Chandra Bose. They record changes in plant growth in a few minutes.

Plant growth Plants, like all living organisms, are capable of growing and developing. But, unlike many animals, the plant grows its entire life. Look at an old, almost dry tree - in spring young shoots appear here and there, green leaves and its growth continues. Growth stops - the plant dies.

Growth is an increase in the size, volume and mass of both the whole organism and its individual parts. That is, growth is quantitative changes in the body. It is caused by cell division and growth. Another feature of plants is that they grow in one place. Therefore, they need the growth of all parts in order to cover the maximum living space.

Plant growth can be continuous or periodic. With the continuous growth characteristic of most of our annuals and many tropical species, the size of the organism or its individual parts increases constantly.

With periodic growth, growth processes alternate with periods of rest, when the growth of the plant temporarily stops. In plants of cold and temperate climates, the suspension of growth processes is associated with a reduction in the length of the daylight period and the onset of winter.

The reaction of plants to the duration of the daylight period is called photoperiodism (from the Greek. Photos and periodos - alternation). The time of the onset of flowering and fruiting of plants depends on this reaction. In tropical plants, periodic growth interruptions are caused by the onset of the dry season. Plant development. We often say that a plant grows and develops.

The development of plants is closely related to their growth, but they are not the same thing. Development is qualitative changes that are consistently occurring in the body and its individual parts throughout life. An example of development is the formation of a flower. Its individual parts are also growing, but on the whole its appearance is a new qualitative state of the whole organism. Therefore, flowering is an indicator of a certain stage in the development of a plant.

All transformations that occur in the body from the moment the zygote is formed to the end of life are called individual development. In the individual development of seed plants, the embryonic and post-embryonic periods are distinguished. The embryonic period begins from the formation of the zygote and continues until the moment of germination of the seed, after which the post-embryonic period begins. It includes the stages of seedling, youth, maturity and old age.

The seedling stage lasts from the moment of germination to the formation of the first green leaves. At this time, the seedling feeds on the reserve nutrients of the seed.

The youth stage is the period of life from the appearance of the first green leaves to the beginning of flowering. At this time, all the vegetative organs of the plant grow and form vigorously. A young plant, unlike a seedling, feeds on photosynthesis.

Further development of one-, two- and perennial plants occurs in different ways. Annual plants complete their growth throughout the year, bloom, form seeds and fruits, and die off. The time of their youth is short (dill, peas, cucumbers): within 30–40 days after germination, they form flowers and soon bear fruit. In biennial plants (cabbage, carrots), only roots and leaves develop in the first year of life. The next year, they form a flowering shoot, seeds and fruits and then die off.

Perennial grasses can bloom and bear fruit for several years, but all their aerial parts die off annually (for example, lily of the valley, wheatgrass, horseradish). Woody perennial trees and shrubs (for example, apple, oak, gooseberries, hazelnuts, currants) reach their maximum size after tens or even hundreds of years, and their first flowering and fruiting occurs only a year later, sometimes several years after germination ... They bear fruit over the years.

The stage of maturity lasts from the beginning of the first flowering until the termination of reproduction with the help of seeds. Over time, even plants with a long life span cease the formation of generative organs. You've probably noticed how old fruit trees bloom less and less and less and less fruit. New shoots almost never appear on them, old ones dry up and die off. In the trunks of old trees, holes are often formed - hollows. This occurs as a result of rotting and withering away of areas of wood.

The final stage of the plant's life cycle - aging - lasts from the end of the last fruiting until the death of the organism.

Having studied the living conditions of plants, man has learned to manage their development. The leading role in the development of plants is played by the temperature factor. The transpiration coefficient can be used to determine the moisture requirement of plants. It is known that many environmental factors act on any plant, however, the development and yield of a plant is limited by the factor that is at a minimum. With an excess of this or that factor, the yield will also decrease. Any cultivated or wild plant needs best conditions, that is, in the cumulative effect of the optimal amount of a particular factor (heat, water, light, soil conditions, etc.). Knowing the biology of plant species and varieties, you can create appropriate optimal living conditions for them in the fields. The action of factors may vary depending on weather conditions, soil fertility, fertilization. It is known that, for example, in windy weather, the transpiration (evaporation) of plants sharply increases. In different periods of growth in the development of the same plant, its need for different environmental factors is not the same.

“For growth, all terrestrial plants need sunlight, because it participates in the process of their nutrition. Food creation, or photosynthesis, occurs primarily in leaves, in which chlorophyll absorbs sunlight and converts it into energy. If you keep a green plant in the dark, it will soon lose its evil color, fade and die. "

"" The plant is 90% water. The production of nutrients by a plant through photosynthesis is impossible without water. Water helps plant cells in the plant to stay firm. If there is not enough water, the cells weaken and the plant dies. Most plants constantly need water from the root system. "

Special plant cells produce ndash hormones; chemical substances - laquo; controllersraquo; which laquo; orderraquo; different plant cells perform certain functions. Plant hormones are responsible for things like fruit development, the death of petals from the plant's flowers and leaves, and most importantly, ndash; they are responsible for growth.

The cells in the tops of stems, new leaves and buds, for example, produce various growth hormones that instruct the plant cells to reproduce by dividing or enlarging.
The growth chart in plants is an illustration of how they differ from animals. While animals grow fully over time (and then live for a long time), plants grow throughout their entire life cycle. In other words, there is no such thing as an adult plant that has stopped growing but continues to live.

How do plants grow?

How do plants feed?

Why do plants need water?

How do ferns grow?

How do plants grow?

Can plants live without sunlight?

Without exception, all plants on earth need sunlight, because it is necessary for the process of their nutrition. The process of creating food in plants is called photosynthesis. " Photosynthesis occurs mainly in the leaves. It absorbs sunlight and converts it into energy for plant nutrition. If the plant is placed in a dark place, it will soon lose its green color, then it will fade and soon die altogether. In the dark, only mushrooms can exist, because they need other plants or inanimate matter to feed them.

How do plants feed?

Why do plants need water?

Plants are about 90% water. The nutrients that plants receive through photosynthesis cannot be produced without water. Almost all plants need water, which they receive through the root system. Water helps plant cells to stay firm. If there is not enough water, the cells become weak and eventually the plant dies.

Why are desert plants at a considerable distance from each other?

Desert plants are scattered over a wide area and do not grow very close to each other, because they would have to grow in a constant struggle for water and scarce nutrients. Desert plants have very long roots, with which they try to capture more moisture and nutrients. During rains, plants absorb as much water as possible in reserve and store it in a fleshy stem.

How do plants keep cool?

Plant leaves evaporate water, which helps them stay cool. This is possible due to small pores or stoogmata. Simultaneously with this process, the roots draw moisture from the soil. Water rises up the stem from the roots. This water carries with it essential minerals from the soil.

How climbing plants crawling up?

This process has different plants happens in different ways. Clematis, for example, winds around a stronger plant and crawls upward along it. In clematis, one half grows much faster than the other, as a result of which it begins to curl around another plant. Ivy uses small roots to climb up the wall. There are also owners of special twisted antennae with which they cling to the wall. These include, for example, peas and sweet peas. Small pads, similar to suction cups, which are attached to a wall or other flat surface are awarded with ampelopsis. Thorns cling to everything possible to help upward growth of climbing roses and kumanik.

Why don't water lily leaves sink?

On the inner surface of the leaves of the water lily there are cavities filled with air. I help these cavities to stay on the surface of the water. The lily has very strong stems that keep the leaves upright. This is how the water lily exposes its leaves to the sunlight, without which it cannot survive.

Why do some plants have thorns?

Thorns, sharp needles and thorns serve the plants to help defend against hungry animals and prevent insects from entering and causing harm. The thistle is very thorny and the cows, eating the grass, do not touch it. Also, the seeds of some plants are very sticky and, attached to animals, are spread over vast territories. " Animals bring these seeds far from the plant, where they begin to germinate.

Why does a fetid morel, or veselka, emit such a smell?

The fetid odor that this mushroom emits serves to lure flies. Flies like this smell, and it attracts them, although for us it is simply terrible. Veselka mushroom spores contain mucus that flies feed on. These spores stick to the feet of the flies, and they carry them over long distances. So this mushroom with the help of flies spreads over a huge territory.

Why is moss very similar to a thick rug?

Moss grows out of the spores. " Spores, germinating, throw out a thinning green thread. Twigs grow on this thread, on which buds are formed. New shoots are formed from these buds. The newly appeared plants are very close to each other and, soon, a rug forms. This moss rug absorbs a huge amount of moisture and distributes it evenly over the soil.

How do ferns grow?

The fern has no flowers, so nature has come up with a different method of reproduction. Red tubercles appear on the inner side of the leaf. From these hillocks, spores pour out onto the soil, from which the plates grow. They contain both female and male cells, which subsequently fuse. And already these plates grow a new fern. Some fern species breed by underground stems such as Bracken.

Do plants have a sense of time?

Most plants can tell the season with amazing accuracy. " Flowering flowers constantly bloom in the same period. Some plants, like animals, store for winter period nutrients in underground roots ”and stems. All this is regulated in plants by the length of day and night changing throughout the year.

Can plants feed on insects?

Insectivorous plants, such as the venus flytrap and sundew, grow in swampy soil that is very poor in the minerals that plants need to survive. These plants have acquired traps for catching various kinds of insects. Traps are not your main food source. There are traps on the tips of the flycatcher's leaves. It is enough for an insect to touch one of the hairs of the trap, as it instantly slams. The plant secretes acid, in which the victim is digested. The acid decomposes the insect into essential plant nutrients.

Botany Beginning

How Plants Grow Surprisingly, in general, plant life is very similar to how humans grow. Everything up to and including many types of plants.

From pollination to pollination - life cycle plants

How plants grow. How can this be changed

Just as humans have essential survival needs, all plants require several basic elements in order to grow and thrive, including ...

Minerals from the soil (the more nutrient-rich the soil is, the better the plant will grow)
Air (carbon dioxide, hydrogen and oxygen)
sunlight
Correct soil temperature
Correct air temperature

How much each element a plant needs initially depends on the plant's original habitat. For example, rainforest plants that require a constantly humid and warm environment might obviously not survive in the desert.

But according to human desire, the ability of a plant should not completely depend on nature. Organic farmers, horticulturists, scientists and researchers have "modified" the characteristics of many essential plants to enable them to thrive in other environments.

Continuing with the example of rainforest plants, if a farmer notices that one crop does not need so much water to grow and bear fruit, he may start to cross-pollinate that plant with another plant with the required qualities, in an attempt to start a new "line" (the so-called "Variety") to create more resilient rainforest plants. With the passage of time and constant cross-pollination, more and more tolerant plants become, so that rainforest plants can "learn" to survive in conditions that are significantly different from their native lands.

This intentional cross-pollination can be applied to any characteristic of a plant ... from resistance (roughly plant immunity,) flower color, fruit flavor and root depth.

Now let's move on to what's going on inside and between plants. Which allows them to grow, flourish and reproduce ...

How to grow plants? Pollination to Pollination: The Life Cycle

At the risk of oversimplifying, the seven stages of the growing cycle are essential ...

Pollination
Fertilization
Seed formation
Seed spread
Germination
Continued growth
Pollination

1. Pollination

While some plants can reproduce asexually (for example, plant a root cut or stem cut and a new plant will work), most plants reproduce sexually through pollination.

During pollination, pollen grains carrying male sperm (gametes) are carried by insects or animals in the female part of the plant, where the gametes come into contact with the female ovum. This can occur either between two plants (cross-pollination) or within the same plant (self-pollination). The reproductive organs of sexually reproducing plants are found there, which we usually call.

2. Fertilization

In some plant species, when a pollen grain containing gametes comes in contact with the female part of a flower (pistil), the pollen grain travels down the tube in an attempt to reach the plant's ovum.

In some plants, pollen can travel up to 40 cm through the tube! When this happens, the gamete will pass through the pollen tube, reach the egg and fertilize the egg.

In other types of plants, the female parts contain a watery fluid through which the flagellated sperm swims their way to fertilize the eggs.

3. Seed Formation

Seed formation begins within the mother plant or plant part. Then it continues to grow inside the fruit in some types of plants (angiosperms) or in the open on the perianth in other types (gymnosperms).

4. Dissemination of seeds

Once the fruit of the plant is ripe or the fruit has opened, its seeds are carried by wind, water, animals, or insects at a time when conditions are ideal for the plant's seeds to germinate and grow.

5. Germination

Germination occurs when a plant germinates from a seed and begins to grow, producing familiar parts, including roots, stems, and leaves. Germination occurs after the plant's seed has landed on the ground or has been trampled into the ground or buried in environment(that is, soil).

6. Continued growth

Unlike animal stem cells, which can only create new types of cells in the early stages of animal development, plants always create new parts based on need from a special tissue called the meristem. Meristems are of two types - one for the roots and one for the upper part - and consists of different types cells that "work" at the right time (we must say, will have an effect on the root or stem),

The process of continuous plant growth is made possible by several processes including photosynthesis, nutrient transfer and transpiration (see our page for more information on these).

7. Pollination

After the plant has grown and matured, it produces its own flowers for pollination and fertilization. Let the circle of life go on forever!

Growth and development are inalienable properties of every living organism. These are integral processes. The plant organism absorbs water and nutrients, accumulates energy, countless metabolic reactions take place in it, as a result of which it grows and develops. The processes of growth and development are closely interrelated, as the body usually grows and develops. However, the rates of growth and development may be different, rapid growth may be accompanied by slow development or rapid development by slow growth. So, for example, a chrysanthemum plant in early summer (long day) grows quickly, but does not bloom, therefore, it develops slowly. A similar thing happens with winter plants sown in spring: they grow rapidly, but do not proceed to reproduction. These examples show that the criteria that determine the rate of growth and development are different. The criterion for the rate of development is the transition of plants to reproduction, to reproduction. For flowering plants, this is the laying of flower buds, flowering. Growth rate criteria are usually determined by the rate of increase in the mass, volume, and size of the plant. The foregoing emphasizes the non-identity of these concepts and allows us to consider the processes of growth and development consistently.

The plant grows both in length and thickness. Longitudinal growth usually occurs at the tops of shoots and roots where the cells of the educational tissue are located. They form the so-called growth cones. Young cells of the educational tissue are constantly dividing, their number and size increase, as a result of which the root or shoot grows in length. In cereals, the educational tissue is located at the base of the internode, in this place the stem grows. The growth zone at the root does not exceed 1 cm, at the shoot it reaches 10 cm or more.

The growth rate of shoots and roots is different for different plants. The record holder for the growth rate of shoots is bamboo, in which a shoot can grow up to 80 cm per day.

The growth rate of the root depends on moisture, temperature, oxygen content in the soil. Tomato, peas, corn have a high oxygen demand, less rice and buckwheat. Roots grow best in loose, moist soil.
Root growth depends on the intensity of photosynthesis. Conditions favorable for photosynthesis have a positive effect on root growth. Mowing the aboveground part of the plants thermally inhibits the growth of roots, leading to a decrease in their mass. A bountiful harvest of fruits also inhibits the growth of the tree's roots, and the removal of the inflorescences promotes root growth.

Photo: MarkKoeber

The growth of plants in thickness occurs due to the division of the cells of the educational tissue - the cambium, located between the bast and the wood. In annual plants, cambium cells stop dividing by the time of flowering, and in trees and shrubs, they stop dividing from mid-autumn to spring, when the plant enters the dormant stage. The frequency of cambium cell division leads to the formation of annual rings in the tree trunk. The annual ring is the growth of wood per year. By the number of annual rings on the stump, the age of the cut tree is determined, as well as the climatic conditions in which it grew. Wide growth rings indicate favorable climatic conditions for plant growth, while narrow growth rings indicate less favorable conditions.

Plants grow at a certain temperature, humidity, and light. During the growth period, organic substances and the energy contained in them are intensively consumed. Organic substances enter the growing organs from photosynthetic and storage tissues. Water and minerals are also required for growth.
However, water and nutrients alone are not enough for growth. We need special substances - hormones - internal growth factors. The plant needs them in small quantities. An increase in the dose of the hormone causes the opposite effect - growth inhibition.
Growth hormone heteroauxin is widespread in the world of plants. If you cut off the top of the stem, then its growth slows down, and then stops. This indicates that heteroauxin is formed in the growing zones of the stem, from where it enters the stretch zone and affects the cytoplasm of cells, increases the plasticity and extensibility of their membranes.
The hormone gibberellin also stimulates plant growth. This hormone is produced by a special kind of lower fungi. In small doses, it causes the elongation of the stem, pedicels, and accelerated flowering of plants. Dwarf forms of peas and maize, after treatment with gibberellin, reach normal growth. Growth hormones remove seeds and buds, tubers and bulbs from dormancy.

In many plants, special substances have been found - inhibitors that inhibit growth. They are found in the pulp of apple, pear, tomato, honeysuckle, in the shells of chestnut and wheat seeds, in sunflower embryos, in onion and garlic bulbs, in the roots of carrots and radishes.
The content of inhibitors increases by autumn, due to which fruits, seeds, roots, bulbs, tubers are well stored and do not germinate in autumn and early winter. However, closer to spring, if conditions are favorable, they begin to germinate, since inhibitors are destroyed during the winter.

Plant growth is a fickle process: the period of active growth in spring and summer is replaced by the attenuation of growth processes in autumn. In winter, trees, shrubs and grasses are dormant.
During the dormant period, growth stops, and the vital processes of plants slow down greatly. For example, in winter their breathing is 100 - 400 times weaker than in summer. However, one should not think that the life activity of plants in a state of rest completely ceases. In the resting organs (in the buds of trees and shrubs, in tubers, bulbs and rhizomes of perennial grasses), the most important vital processes continue, but growth completely stops, even if there are all the conditions for this. It is difficult to "awaken" the plants during the period of deep dormancy. For example, freshly harvested potato tubers will not germinate even in warm and wet sand. But after a few months, the tubers will sprout and this process will be difficult to delay.

Rest is the body's response to changes in environmental conditions.
Changes in environmental conditions can lengthen or shorten the dormant period. So, if you artificially lengthen the day, then you can delay the transition of plants to a state of dormancy.
Thus, plant dormancy is an important adaptation to the experience of unfavorable conditions that arose in the course of evolution.
Growth processes underlie plant movement. Plant movements are different. Tropisms are widespread in nature - bends of plant organs under the influence of a factor acting in one direction. For example, when a plant is illuminated from one side, it bends towards the light. This is phototropism. The plant bends because its organs on the lighted side grow more slowly than on the non-lighted side, since light slows down cell division.
The response of plants to gravity is called geotropism. The stem and root react differently to gravity. The stem grows upward, in the opposite direction to the action of gravity (negative geotropism), and the root grows downward, in the direction of the action of this force (positive geotropism). Turn the sprouting seed upside down and stem down. After a while, you will see that the root will bend downward, and the stem upward, i.e. they will take their usual position.

Plants react with movement to the presence in the environment. chemical substances... This reaction is called chemotropism. It plays an important role in mineral nutrition, as well as in the fertilization of plants. So, in the soil, the roots grow towards the nutrients. But they bend in the opposite direction from pesticides, herbicides.
A grain of pollen germinates, as a rule, only on the stigma of the pistil of plants of its own species, and sperm (male germ cells) move towards the ovule, to the egg cell and the central nucleus located in it. If a pollen grain falls on the stigma of a flower of another species, then it first germinates and then bends in the opposite direction from the ovule. This indicates that the pistil secretes substances that stimulate the growth of "its" pollen grain, but suppress the growth of foreign pollen.
Plants respond with tropisms to the effects of temperature, water, and organ damage.
For plants, another type of movement is also characteristic - nastia. The growth of the plant, which is caused by various irritants acting on the plant as a whole, is also the cornerstone of the infusions. Distinguish between photonastia, caused by changes in illumination, thermonastia, associated with a change in temperature. Many flowers open in the morning and close in the evening. react to changing lighting. For example, in the morning, in bright sunlight, dandelion baskets open, and in the evening, with a decrease in illumination, they close. The flowers of scented tobacco, on the contrary, open in the evening, with a decrease in illumination.
The basis of nastya, like that of tropisms, is also uneven growth: if the upper side of the petals grows stronger, the flower opens, if the lower one closes. Consequently, the movement of plant organs is based on their uneven growth.
Tropisms and nastias play an important role in the life of plants, this is one of the signs of the adaptability of plants to their environment, to an active response to the effects of various factors.

Photo: Sharon

Growth processes are an integral part of the individual development of plants, or ontogenesis. All individual development of an individual is composed of a number of processes, certain periods in the life of an individual, from the moment of its appearance until its death. The number of periods of ontogenesis and the complexity of development processes depend on the level of plant organization. Thus, the individual development of unicellular organisms begins with the formation of a new, daughter cell (after the division of the mother cell), continues during its growth and ends with its division. Sometimes unicellular organisms have a dormant period - with the formation of a spore; then the spore germinates and development continues until the cell divides. With vegetative reproduction, individual development begins from the moment of separation of a part of the maternal organism, continues with the formation of a new individual, its life and ends with death. In higher plants, during sexual reproduction, ontogenesis begins with fertilization of the egg and includes periods of development of the zygote and embryo, the formation of a seed (or spore), its germination and the formation of a young plant, its maturity, reproductive capacity, wilting and death.

If in unicellular organisms all the processes of their development and life occur in one cell, then in multicellular organisms the processes of ontogenesis are much more complicated and consist of a number of transformations. In the course of the development of a new individual, as a result of cell division, various tissues are formed (integumentary, educational, photosynthetic, conductive, etc.) and organs that perform various functions, the reproductive apparatus is formed, the body enters the reproduction time, gives offspring (some plants - once in a lifetime , others annually for many years). In the process of individual development, irreversible changes accumulate in the body, it grows old and dies off.
The duration of ontogenesis, i.e. the life of an individual also depends on the level of organization of plants. Single-celled organisms live for several days, multicellular organisms - from several days to several hundred years.

The duration of development of plant organisms also depends on environmental factors: light, temperature, humidity, etc. Scientists have established that at a temperature of 25 ° C and above, the development of flowering plants accelerates, they bloom earlier, form fruits and seeds. Abundant moisture accelerates the growth of plants, but retards their development.
Light has a complex effect on the development of plants: plants react to the length of the day. In the process of historical development, some plants develop normally if the duration of daylight hours does not exceed 12 hours. These are short-day plants (soybeans, millet, watermelon). Other plants will flower and form seeds when grown over a longer day. These are long day plants (radishes, potatoes, wheat, barley).

Knowledge about the patterns of growth and individual development of plants is used by humans in practice when growing them. Thus, the property of plants to form lateral roots when the tip of the main root is removed is used when growing vegetable and ornamental plants. Seedlings of cabbage, tomatoes, asters and other cultivated plants when transplanted into open ground pinch the tip of the root, that is, they carry out a pick. As a result, the growth of the main root in length stops, the growth of lateral roots and their distribution in the upper, fertile layer of the soil increases. As a result, plant nutrition improves and their yield increases. Picking is widely used when planting cabbage seedlings. The development of a powerful root system is facilitated by hilling - loosening and rolling the soil to the lower parts of the plants. In this way, the flow of air into the soil is improved and thus normal conditions are created for respiration and root growth, for the development of the root system. This, in turn, improves the growth of leaves, as a result of which photosynthesis is enhanced and more organic matter is formed.

Trimming the tops of young shoots, such as apple, raspberry, cucumber, stops their growth in length and increases the growth of lateral shoots.
Currently, growth stimulants are used to accelerate the growth and development of plants. They are usually used for grafting and transplanting plants to accelerate root formation.
For economic purposes, it is sometimes necessary to slow down the growth of plants, for example, the germination of potatoes in winter and especially in spring. The appearance of sprouts is accompanied by a deterioration in the quality of tubers, a loss of valuable substances, a decrease in starch content, and an accumulation of the poisonous substance solanine. Therefore, to delay the germination of tubers before laying them for storage, they are treated with inhibitors. As a result, tubers do not germinate until spring and remain fresh.

The general scheme of development of each organism is programmed in its hereditary basis. Plants vary dramatically in life expectancy. Plants are known that complete their ontogenesis within 10-14 days (ephemera). At the same time, there are plants that have a lifespan of thousands of years (sequoias). Regardless of their lifespan, all plants can be divided into two groups: monocarpic, or fruiting once, and polycarpic, or fruiting many times. Monocarpic plants include all annuals, most biennials, as well as some perennials. Perennial monocarpic plants (for example, bamboo, agave) begin to bear fruit after several years of life and die off after a single fruiting. Most of the perennials are polycarpic.