Onion plants are not as clearly divided into roots, stems and leaves as we are used to seeing in other garden and vegetable crops. Onion leaves are tubular or fist-shaped, hollow inside or flat (Fig. 1), of various shapes and sizes. For example, onions have a fanny leaf, garlic has a flat linear leaf, tapering towards the end without a cavity; in wild garlic it is also flat, but wide and lanceolate in shape. The cotyledon and the first true leaves of all types of onions are fistulous. The lower parts of the leaves are tubular sheaths from which false stems are formed, and when thickened, bulbs.

The color of the leaves ranges from light to dark green, even bluish. Typically, onion leaves are covered with a waxy coating of varying intensity, but it may be absent. The waxy coating performs a protective function, protecting the leaves from damage by phytopathogens and damage by virus carriers. The number of leaves varies from one or two to forty or more. The stem of the onion is greatly shortened and is called the bottom (Fig. 2). One or more buds (buds) develop at the bottom, which are surrounded by leaf sheaths. In vegetatively propagated plants (propagated using plant parts rather than seeds) the lower part of the bottom - the remainder of the bottom of the mother bulb - is called the heel. The dead tissue of the heel is very dense and hard and prevents moisture from reaching the bottom, protecting the bulb from premature root regrowth. Bulbs grown from seeds do not have heels. A certain number of buds, or rudiments, are formed on the bottom, which is called rudimentary, and the property of forming a certain number of bulbs on one bottom from rudiments is called nesting.

Fig 2. The structure of the bulb (on the left - longitudinal section, on the right - transverse): 1 - dry integumentary scales; 2 - open juicy scales; 3 - closed juicy scales; 4 - rudiments; 5 - bottom; b - heel; 7 - neck Varieties of onions can be single-germ (resp. single-cell), medium- and multi-germ. The primordium and the nesting that depends on it are determined by the degree of branching of the onion and serve as varietal characteristics. Short side shoots - buds - are located on the stem-bottom in a spiral. They are called branches. The buds on the bottom do not form simultaneously - their formation occurs gradually during the growing season and during storage. Subsequently, new bulbs or peduncles with inflorescences develop from the buds.

As leaves develop, a false stem is formed from their sheaths. It is supported in an upright position by young leaves growing in the center from the inside (Fig. 3). As it grows, the bases of the leaves thicken and fleshy scales form, from which the bulb is formed. Gradually the leaves die off, starting from the very first ones in time to appear, the false stem dries out, forming the neck of the bulb. The sooner the neck dries out, the thinner it is and the sooner the bulb ripens. The bulb consists of a bottom with modified scale leaves sitting on it and a bud inside. The outside of the onion bulb is covered with dry scales of various colors (see Fig. 2). The outer shells of the bulb, which protect it from adverse external influences, for different types of onions can be thick or thin, leathery, filmy, papery, fibrous, mesh, etc.

Rice. 3. Scheme of leaf formation in onions: I - leaf blade; 2 - leaf sheaths; 3 - false stem; 4 - shoot growth point; 5 - germinal root; b - adventitious roots Their color is also very diverse - white, gray, yellow, brown, dark red, purple in different shades. Succulent scales are of two types: external open and internal - cone-shaped closed. This can be clearly seen if you cut an onion bulb lengthwise down the center. Exposed scales are thickened parts of green leaves in which reserve nutrients are deposited. With the beginning of thickening of the open juicy scales of the onion, leaves of a different type appear inside the bulb - closed scales. These are non-assimilating modified leaves that serve to store nutrients.

The ratio of closed and open scales is an important indicator of the keeping quality of the bulbs. The more closed scales, the better and longer the onion is stored. When closed scales are formed, the growth of new leaves stops, the false stem remains hollow inside, and the onion lies down under the weight of the leaves. Lodging is an important sign indicating the beginning of bulb maturation. Due to the drying of several outer succulent scales, dry integumentary scales of a specific color for a given variety are formed. Onion types are characterized by a wide variety of bulbs. They can be real, like the onion bulb described above, or false, without closed scales. The most interesting is the collective garlic bulb, consisting of onion-teeth. For many species, for example, onion, chives and others, the formation of only false bulbs is characteristic, which do not ripen and cannot be stored. Externally, false bulbs differ from real bulbs in the smaller thickening of the leaf sheaths, the absence of a pronounced neck - the transition from the false stem to the bulb itself is not sharp, but smooth. The shape of such bulbs is elongated (Fig. 4). The mass of the bulbs can vary - from 1 g or less to 1 kg, depending on the species, variety, location and growing conditions. In many species, small baby bulbs are formed on the bottom, as well as bulbs on the stolons. In garlic, multi-tiered onions, blue onions and other onions, small bulbs, called bulbs, are formed in inflorescences along with flowers or instead of flowers. The development of bulblets in an inflorescence is called viviparity (from the Latin word vivus - alive, in pairs - to give birth), or viviparity. The bulbs are colored, often unevenly, green or purple. Fig 4. Scheme of the structure of the onion: 1 - leaves; 2 - longitudinal section of the false bulb; 3 - rhizome; 4 - roots; 5 - sighting bulb; b - peduncle Aerial bulbs are used for vegetative propagation; as a rule, their formation is associated with a decrease in the ability of plants to form normally developed seeds. Most perennial onion species have a rhizome. A rhizome is a modified stem located in the soil and similar in appearance (brown color, lack of green leaves) to a root. On the rhizome you can see modified leaves - scales, which are short-lived and quickly fall off. The rhizome has internodes in which buds are formed, which subsequently give rise to new shoots.

Rhizomes can have shortened internodes and crowded buds, which leads to close arrangement of shoots, or long internodes, like wheatgrass. The latter reproduce better, since the shoots formed at the nodes spread faster throughout the area. The rhizome plays an important role in the vegetative propagation of onions. When the old parts of the rhizome die off, the shoots of the plant separate and become independent plants. The rhizome of onions serves as a reservoir for reserve nutrients. False bulbs are attached to it. The bottoms of the latter either directly continue the rhizome or are delimited from it. However, young shoots always use nutrients from bulbs and rhizomes that store scales for development.

Onions are considered plants with a weak root system, which determines their increased demands on soil conditions, especially in the first stages of development from seeds. At the same time, certain species, for example, Pskem onion, which grows in nature in rock crevices and on mountain screes, have very strong, powerfully developed roots that allow them to exist in such harsh conditions.

Species such as onions, which form true bulbs, have a fibrous root system that does not penetrate deeply into the soil and is weakly branched. The roots of these species are annual, dying off simultaneously with the end of the growing season of the above-ground organs. In species with a well-developed rhizome and a long growing season, for example, the slime onion, roots form both on the bulbs and on the rhizomes. However, the nature of these roots is different. The roots of the bulbs spread horizontally and branch strongly until the formation of third-order roots. They are annual, that is, they die off at the end of the growing season. The roots extending from the rhizome are perennial, spread vertically in the soil, and do not branch very much - until the formation of second-order roots. The depth of penetration of the latter is 60...80 cm. There is information about deeper penetration of the roots of onions (up to 120 cm), perennial onions (up to 150 cm), but these are only single roots. The flowering shoot of an onion is called a peduncle or flower arrow . The peduncle develops when the formation of leaves is completed and they begin to die. The arrow emerges from the false stem in the axil of the last leaf (Fig. 5). Onions have a green flower arrow. Due to its photosynthetic activity, the formation and filling of seeds is ensured. The size, shape of peduncles and their number vary among onion species and varieties. Cross sections of flower arrows of different types were shown in Figure 1. Onions have narrow bases of flower arrows, then widen

Fig 5. A flowering plant of Altai onion swells, forming a swelling, and narrows again towards the inflorescence. The swelling on the flower arrows has an adaptive significance. It helps to increase the resistance of flower stalks to lodging. The timing of planting has a great influence on the number of primordia, and therefore flower shoots. The inflorescence of onions is a simple multi-flowered umbrella, the shape and number of flowers in which depend on the type of plant. There may be several flowers, or there may be up to a thousand or more. Usually onion flowers are small - 0.3...1 cm in diameter, in some species they are large - up to 3 cm, but at the same time they bear little resemblance to the flowers of other onions.

The young inflorescence is initially covered with a filmy wrapper of several fused leaves. The wrapper is called a cover or blanket. Its shape and size serve as species and varietal characteristics. As the buds grow and the inflorescence expands, the sheath breaks and dries, releasing the inflorescence before the flowers begin to bloom. The diameter of the inflorescence is from 5 to 15 cm. The primordia of flowers on the common receptacle of the inflorescence are not initiated and formed simultaneously. This causes flowers to bloom at different times in the inflorescence.

The duration of flowering of individual flowers in the southern regions is one to two days, in the middle zone it is five to seven. In total, the onion inflorescence blooms from 15 to 35 days. The whole plant blooms even longer, since the inflorescences also form and develop at different times. In onions, the flowers of the first tier usually bloom first (at the top of the inflorescence), the buds of the second tier at this time have short pedicels and are located under the flowers of the first tier, and the small buds of the third tier are located at the base of the inflorescence. Some of the buds of the third tier, as a rule, dry out without opening. As the flowers of the previous tier fade, the pedicels of the buds of the next tier lengthen and carry the blooming buds upward. By the end of flowering, the pedicels of the latest flowering flowers of the third tier are the longest. Onion flowers have a regular symmetrical shape, without a calyx. The corolla has six petals of very varied colors - white, yellow, greenish, pinkish, blue, purple in different shades, etc. The petals often have a dark central vein. There are six stamens, one pistil (Fig. 6). The anthers of the stamens, as well as the petals of the corolla, have different colors, and the pedicels also have different colors. Nectaries are located at the base of the ovary of onions. The flowers of some species, such as alliums, have a pleasant aroma, completely different from the usual pungent odor of onions. The fruit of an onion is a dry three-lobed capsule in which up to six seeds can form, but more often two or four are set. The seeds are black (sometimes called nigella), irregular triangular in shape, covered with a hard, wrinkled, horn-like shell that protects well from adverse influences. Fig b. Onion flower and fruit: a - flower during flowering; b - seed capsule when filling seeds; c - opened capsule with a seed. The size, shape and weight of the seeds are characteristic of the species, although significant variability is observed. Small-seeded species include chives; 1 g contains from 800 to 1000 seeds; onions have much larger seeds - only 250...400 seeds per 1 g. The seeds of ephemeroid onions are even larger - there are about 200 seeds in 1 g. The shape can be flat-convex, concave-convex, triangular, spherical. The biological characteristics of onion seeds also depend on the conditions in which the species was historically formed in nature. Conventionally, they can be divided into three groups: firstly, seeds of species formed under conditions of sufficient moisture favorable for the development of onions; this includes onions and spring onions; these seeds do not have a dormant period and can germinate at temperatures from 4 to 30 °C. They can be sown at any time - in spring, summer, before winter; secondly, seeds of species formed in zones of sharply continental arid climate, including onions from Central Asia and all ephemeral species; the seeds of such onions are large, have a dormant period, and germinate well at temperatures from 4 to 10 ° C; they should be sown only before winter; thirdly, seeds with an extended germination period; types of onions with such seeds grow in harsh conditions; their most important property is the non-simultaneity of germination, which serves as an adaptation for survival; wild garlic has these seeds; if seedlings of one period of germination die due to unfavorable conditions, the species survives at the expense of seedlings of other periods; seeds of this group are also sown before winter.

In most cases, it takes 40 to 60 days for the seeds to fully form. Seed development begins after pollen reaches the stigma of the pistil. The development of seeds is distinguished: the phase of milky ripeness - the age of the seeds is 20...25 days; at this time they are immature, unripe, still soft and when pressed, a white liquid similar to milk flows out of them; ripening when picking fruits in this phase is impossible; waxy ripeness phase - seed age is 30...35 days; the seeds are almost formed, have become hard, and are only slightly deformed when pressed; some are already able to germinate; seeds harvested in waxy ripeness ripen well; the phase of complete biological ripeness of seeds; occurs in onions, depending on the variety and place of cultivation, on the 50...60th day after fertilization; characterized by cracking of the bolls and spillage of seeds, the latter at this time are well formed, hard, germinating by 95...98%. Preservation of seed viability depends on their humidity and storage conditions. When stored in constantly changing conditions, seeds quickly lose their viability within two to three years.

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Onions - beneficial properties and growing conditions

Bulb onions

Using onions in nutrition

Onions are incredibly important in our diet, but at the same time they are often invisible in dishes. In salads made from fresh vegetables, it is, of course, immediately visible, but in the first and second courses it seems to be hidden, and you fully realize how necessary it is for their overall taste only when it suddenly isn’t there. At the same time, it is easier to list those dishes for which it is not needed than those in which it is put. And although, if measured only by weight, we eat little onions, this is the only vegetable that we need every day for health.

Useful properties of onions

Onion is one of the most ancient vegetables, known for at least 6,000 years, but, most importantly, it is one of the most useful. Even those who don’t like onions still rarely give up onions completely, because as a preventive remedy for many diseases, only garlic can compete with them. But there is no medicine. And it protects against almost the most common diseases, such as colds and flu. In the fall, those who don’t want to sit on sick leave or just sniffle can’t do without it. But the medicinal properties of onions are not limited to getting rid of colds: the phytoncides it contains destroy the causative agents of even such dangerous diseases as tuberculosis, diphtheria, or typhus and cholera, which have almost disappeared today, but which in the past wiped out entire cities. It also contains vitamins, and also in considerable quantities. And it is no coincidence that our ancestors said about onions that they are “a disease of seven.” And even now medicines are made from it. And onions have one more very useful property: for those who eat a lot of them fresh, wrinkles do not appear for much longer. Agree, for this reason you can tolerate the smell of it, especially if you eat it at home, after work. On the other hand, onions can be used as a natural substitute for pesticides in the same garden - an infusion from it repels many pests, not to mention the microbes that die from it.

Bow structure

The most common of the cultivated bunches was called onion because its bulb looks like a turnip. At its core, it is something like a head of cabbage, because it is formed by parts of leaves, with the difference that in the onion they have changed much more and not all of them - some have turned into scales, and the rest are feathers sticking out above the bulb. The uppermost scales of the onion dry out and serve the rest as additional protection (Fig.). The roots of the onion are fibrous; they do not go too deep. The bottom of the bulb is actually a stem, only very different from itself, but it is on it that the buds are laid and develop, from which new leaves are formed (more precisely, their nests, of which there may be several), and when the time comes, also peduncle - an arrow with a ball-shaped inflorescence on top. If you look closely at its small flowers, you will notice that each one is shaped like a tiny tulip or lily. And this is also no coincidence - onions are part of the lily family and are closely related to lilies.

Rice. Onion in section: 1 – juicy scales; 2 – dry scales; 3 – feather; 4 – bottom; 5 – roots

But the onion itself has three subspecies, outwardly similar, but with slightly different requirements for conditions and care - these are the northern (sharp) onion, the southern (sweet) onion and the white onion.

Northern onions are the most unpretentious and cold-resistant. Its seeds germinate at +5°C, and the seedlings tolerate light frosts well. Its bulbs are usually not too large, often multi-cavity and the most durable, and the taste is the most “evil”.

Southern onions are heat-loving; in cold regions they not only grow poorly, but also lose varietal qualities, primarily the sweetness for which they are valued. Frosts can destroy it. The bulbs of southern sweet and semi-sweet (semi-sharp) onions are usually large, but poorly stored, so they are used mainly for salad.

We only recently got white onions. In terms of its love for warmth, it is average between spicy and southern, in taste it is closer to the southern, and its main value is that after eating it there is no bad breath left. When moving to the north, its taste almost does not deteriorate, but white onions do not tolerate frosts well, and therefore even in central Russia they have to be protected by them.

Read more about the variety of varieties of onions in the article “The best varieties of onions.”

In this case, all three subspecies can use a feather.

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Botanical characteristics of onions

Onion (Allium cepa) is a biennial plant with a weak root system and a well-defined bulb. Onion plants are not as clearly divided into roots, stems and leaves as is observed in other garden crops. The lower parts of the leaves are tubular sheaths from which false stems are formed, and when thickened, bulbs.

Root system. Onions are considered plants with a weak root system, which determines their increased demands on soil conditions, especially in the first stages of development from seeds. Species such as onions, which form true bulbs, have a fibrous root system that does not penetrate deeply into the soil and is weakly branched. The roots of these species are annual and die off simultaneously with the end of the growing season of the above-ground organs.

The structure of the stem. The stem of the onion is greatly shortened and is called the bottom. One or more buds (buds) develop at the bottom, which are surrounded by leaf sheaths. In vegetatively propagated plants (propagated using plant parts rather than seeds) the lower part of the bottom - the remainder of the bottom of the mother bulb - is called the heel. The dead tissue of the heel is very dense and hard and prevents moisture from reaching the bottom, protecting the bulb from premature root regrowth. Bulbs grown from seeds do not have a heel. A certain number of buds, or rudiments, are formed on the bottom, which is called primordia, and the property of forming a different number of bulbs on one bottom from the rudiments is nestedness.

Leaf structure. Onion leaves can be tubular or fist-shaped, hollow inside or flat, of various shapes and sizes. For example, the leaves of onions are fist-shaped, those of garlic are flat and linear, tapering towards the end without a cavity, and those of wild garlic are also flat, but lanceolate and wide. The cotyledon and the first true leaves of all types of onions are fistulous.

Cross section of a leaf (top) and peduncle (bottom) of different types of onion.

The color of the leaves varies from light green to dark green, even bluish. Typically, onion leaves are covered with a waxy coating of varying intensity, but it may be absent. The waxy coating performs a protective function, protecting the leaves from damage by phytopathogens and damage by virus carriers. The number of leaves varies from one or two to forty or more.

The structure of the bulb. The bulb consists of a bottom with modified leaves sitting on it - scales and a bud inside. The outside of the onion bulb is covered with dry scales of various colors. The outer shells of the bulb, which protect it from adverse external influences, in different types of onions can be thick, thin, leathery, filmy, papery, fibrous, mesh and others.

Their color is also very diverse - white, gray, yellow, brown, dark red, purple in different shades. Juicy scales are of two types: external open and internal - cone-shaped closed. This can be clearly seen if you cut an onion bulb lengthwise down the center. Exposed scales are thickened parts of green leaves in which reserve nutrients are deposited. With the beginning of thickening of the open juicy scales of the onion, leaves of a different type appear inside the bulb - closed scales. These are non-assimilating modified leaves that serve to store nutrients. The ratio of closed and open scales is an important indicator of the keeping quality of the bulbs. The more closed scales, the better and longer the onion is stored. When closed scales are formed, the growth of new leaves stops, the false stem remains hollow inside, and the onion lies down under the weight of the leaves.

The structure of the bulb (on the left - longitudinal section, on the right - transverse):

1 - dry integumentary scale; 2 - open juicy scales; 3 - closed juicy scales; 4 - rudiments; 5 - bottom; b - heel; 7 - neck.

Varieties of onions can be single-budded (respectively, single-celled), medium-budded and multi-budded. Short side shoots - buds - are located on the stem-bottom in a spiral. They are called branches. The buds on the bottom do not form simultaneously - their formation occurs gradually during the growing season and during storage. Subsequently, new bulbs and peduncles with inflorescences develop from the buds.

According to the number of rudiments, varieties are distinguished: one, two, few rudiments and multi-germs. Each primordium develops leaves and then a flower stalk. Low-bud varieties usually form large bulbs with thick, juicy scales with a slightly pungent taste. These include mainly southern salad varieties. Sharp varieties most often have multi-primed bulbs with thin, juicy scales tightly adjacent to one another.

Longitudinal section of onion bulbs differing in the number of rudiments:

1 - single germ; 2 - two-germ; 3 - multi-primordial; 4 - shooting bulb: a - arrow, b - shooting bulb.

Bulbs can be of various sizes - from 5...20 grams to 800 grams, as well as of various shapes.

Bulb shapes of different varieties of onions: flat, rounded-flat, rounded, melon-shaped, elongated-meloned and long.

The structure of a flowering shoot. The flowering shoot of an onion is called a peduncle or flower arrow. The peduncle develops when the formation of leaves is completed and they begin to die. The arrow emerges from the false stem in the axil of the last leaf. Onions have a green flower arrow. Due to its photosynthetic activity, the formation and filling of seeds is ensured.

Flower arrows develop from primordia. Therefore, by the number of primordia, you can determine the number of flower arrows in the seed bulb. The arrows are hollow, tender, of varying heights (50...175 cm) depending on the variety (mainly on the size of the bulb) and growing conditions. The size, shape of peduncles and their number vary among onion species and varieties. In onions, the bases of the flower arrows are narrow, then expand, forming a swelling, and the ends narrow again.

The inflorescence of onions is a simple multi-flowered umbrella, the shape and number of flowers in which depend on the type of plant. There may be several flowers, or there may be up to a thousand or more. The duration of flowering of individual flowers in the southern regions is 1...2 days, in the middle zone - 5...7 days. In total, the onion inflorescence blooms from 15 to 35 days.

The structure of flowers. Onion flowers have a regular symmetrical shape, without a calyx. The corolla has six petals of very varied colors - white, yellow, greenish, pinkish, blue, violet. The petals often have a dark central vein. Six stamens, one pistil. The anthers of the stamens, as well as the petals of the corolla, have different colors, and the pedicels also have different colors. Nectaries are located at the base of the ovary of onions. The flowers of some species, such as allium, have a pleasant aroma, completely different from the usual pungent odor of onions.

The structure of the fruit. The onion fruit is a dry three-lobed capsule in which up to six seeds can form, but more often two to four are formed. The seeds are black (sometimes called nigella), of irregular triangular shape, covered with a hard horn-like shell, which well protects the seeds from adverse influences.

Onion flower and fruit:

a - flower during flowering; b - seed capsule when filling seeds; c - opened seed capsule.

The size and weight of the seeds are characteristic of the species. Small-seeded species include chives; 1 gram contains from 800 to 1000 seeds; onions have much larger seeds - only 250-400 seeds per gram. Most seeds take 40 to 60 days to fully form. Development begins after pollen hits the pistil.

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The structure of the bulb, rhizome, tuber

The bulb is an underground shoot with leaves closely attached to the bottom. The structure of the bulb is the same in different plants, but may differ in shape and size. In their structure, all the bulbs are similar to the usual onions.

General structure

Looking at the structure of the bulb in a section, you can see that there is a bottom at the very bottom. Below it are the roots, and above it are the modified shoots. They accumulate nutrients during the dormant period.

Modified shoots include not only bulbs, but also rhizomes and tubers. Plants with rhizomes are irises, wheatgrass, and nettles. There are few tuberous plants; one of the most famous is potatoes. It has shoots underground, on the upper parts of which tubers grow. They have shortened internodes and do not contain chlorophyll. However, when the tubers are exposed and exposed to direct sunlight for a short period of time, the tubers may turn green.

Looking at the structure of the bulb, you can see the embryos of the leaves. They accumulate a large amount of nutrients. They allow leaves to start growing at any time of the year. Therefore, bulbous plants are used for early forcing, planting them in winter. This is their difference from other plants. Another difference is that bulbous plants have a precisely defined number of leaves, that is, the number of primordia is equal to the number of leaves.

In the lower part of the bulbs, near the bottom, there are flower buds. How many buds are laid, so many flower shoots will grow.

When caring for bulbous plants, you should carefully tear off damaged and dried leaves, since if the rudiments are damaged, the leaf dies, and if the damage is severe, the entire bulb may die.

In different plants, the scales of the bulb adhere to each other in different ways. In lilies, they are located loosely against each other, but there are plants with a tight fit, such as hyacinths.

Types of bulbs

The internal and external structure of the bulb is different for different types of plants. They are divided into the following subspecies:

• Film. The scales can cover the entire internal part. The scaly edges touch. There are plants whose scales can grow together.
• Semi-tunic. There are scales that never grow together.
• imbricated. The scales are very narrow. At one edge they come into contact with neighboring scales.
• The number of scales varies from plant to plant. Some may have one, others three, five or more.

All scales are divided into:

• leafy;
• grassroots.

From below, the scales grow, storing nutrients in them.

Tuber structure

The internal structure of the tuber and bulb is different. On the outside of the tubers there are sprouts - they are called eyes. There are more of them on the apical part than on the lower part. When planted in the ground, the above-ground part grows from the eyes.

On the underside of the tubers there are stolons. They receive nutrients. They accumulate in the shoots, then active growth and thickening of the shoots occurs, and by autumn tubers grow on the stolons.

The structure of the bulb and tuber are similar only in that they accumulate substances useful to the plant. Otherwise they are different.

Rhizome structure

A rhizome is also an underground shoot of a modified type that develops in perennials and shrubs. It, like the bulb, stores the nutrients the plant needs for normal development and maintenance of life.

The external structure of the rhizome of the bulb resembles a regular root, but is distinguished by dissected internodes and scaly leaves on which axillary buds are formed. When the aerial part dies, a scar remains on the rhizome.

There are simple, thin, horizontal, thick, branched, vertical and ascending rhizomes. These are not all rhizome options.

The lifespan of the rhizome is on average five years. In some plants it can live for two years, and in others for more than ten years.

Conclusion

The rhizome, tuber and bulb of plants are different types of modified shoots. They are similar in that they have short internodes and accumulate a large supply of microelements and other nutrients. These plant organs do not contain chlorophyll.

Underground shoots are storehouses of vital substances. They contain starch, mineral elements, and phytoncides. These parts of plants can be used for human food and also used as animal feed.

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Botanical features of onions | Our Gryadka.ru

Onions belong to the lily family. The genus of onions (allium) has about 400 species, more than half of which grow in our country, mainly in the mountainous regions of Alai, as well as in Central Asia. Of this total number of species, only seven are in cultivation: onions, shallots, batun, portray, garlic, chives or chives, and the recently introduced multi-tiered onion.

Many of the wild onions are used as food by the local population, and some are even stored for future use, such as the skoroda onion, which grows in abundance in the meadows of the Volga region and Siberia. In Kazakhstan, eleven types of wild onions are used for food, including onion forms. Among the onions there are also beautifully flowering ornamental species that can take a place in our flower beds.

Onion is a perennial plant. Its development cycle from seed to seed is two to three years. Onions overwinter in the form of a bulb.

The base of the bulb (bottom) is the actual stem of the plant, shortened and expanded in width. At the top of the bottom there are one or several growth points - rudiments, which are clearly visible in the cross section of the bulb. The buds are surrounded by succulent scales of the bulb, which are the bases of the leaves with nutrients deposited in them. The outside of the bulb is covered with dry scales, protecting it from drying out and damage. Usually there are from two to five, they are colored, depending on the variety, in white, yellow and red, in different shades. The denser the dry scales and the more of them, the more stable the onion is in storage. The lower part of the bottom is called the heel. The older the bulb, the larger it is. In annual onions, the heel is small and covered with remnants of roots.

Onion roots are straight, string-shaped, poorly developed, have few root hairs and go vertically into the soil to a depth of no more than 60-80 centimeters. According to Professor Edelstein, the volume of soil used by onion roots is 20-25 times less than that of carrots or cabbage. Therefore, onions are very demanding regarding the content of nutrients in the soil and respond well to fertilizing and loosening the soil.

Onion leaves are tubular and hollow. Each new leaf grows inside the previous one in such a way that the bases of all the leaves, nested one inside the other, form a false stem. This stem is supported in an erect position by the growing young leaf. When the growth of new leaves stops, the false stem goes down, and the nutrients from the leaves move into the bulb.

The size of the bulb depends on the number and size of leaves: the more powerful the leaves and the more of them, the larger the bulb. Agricultural technology for growing onions should be designed in such a way as to provide the best conditions initially for rapid growth, and in the second half of summer for rapid ripening of the bulb. The better the bulb ripened and the earlier it went into a dormant state, the better it is stored in winter. Depending on the conditions of winter storage, onions planted in the ground in the spring either shoot or form a nest of daughter bulbs.

To begin flowering, the bulb must go through the vernalization stage, which occurs at a temperature of 2 to 15 degrees throughout the entire period of ripening and storage of the bulb. Onions that have undergone vernalization after planting in the ground produce from one to five arrows. The flower arrow bears 200-800 flowers per inflorescence - an umbrella. The inflorescence is covered with a membranous involucre, which falls off before flowering begins. The flowers are quite small, greenish-white, have a network of petals and six stamens. The ovary is confluent, three-locular.

The ripe fruit is a triangular capsule containing a maximum of six seeds. The seeds are black, triangular, in a wrinkled horn-like shell. Because of their black color, onion seeds are called “nigella”. Thanks to their dense shell, onion seeds swell poorly and, if there is not enough moisture in the soil, germinate very slowly.

A single onion cotyledon appears on the soil surface in the form of a loop. Continuing to grow, the loop pulls the upper end with the remnants of the seed shell out of the soil. After three to five days, the first true leaf sprouts at the base of the loop. The next two or three onion leaves are still very small and grow slowly. Only 25-30 days after the emergence of seedlings, starting from the fourth or fifth leaf, their size increases and growth proceeds faster.

If the onion at the stage of three or four leaves does not have enough moisture and nutrition, then a small onion is formed, consisting of one or two juicy scales. Such an onion, from 1.5 to 2 centimeters in diameter, is called a set. It is obtained by heavily thickened sowing as planting material for growing large onions.

And, conversely, by continuously supplying the onion plant with moisture and nutrients, you can make it grow until late autumn. The plant will develop a large number of powerful leaves, but the bulb will not go into a dormant state - it will not ripen. Knowing the needs of a plant at different periods of its development, you can control its growth and obtain the products that are needed.

1 - wild garlic; 2 - onions; 3 - chives; 4 - garlic

Requirements of onion plants to environmental conditions

The main environmental conditions that determine the growth and development of a plant are light, heat, moisture and food. Onions are undemanding to light intensity, but still do not tolerate strong shading.

Northern onions are long-day plants. With a short day (less than 12 hours), the formation of the bulb is greatly delayed, and the leaves grow faster. In the central zone, the Urals and the Volga region, where the day length in June-July is 16-18 hours, there are all conditions for the rapid formation of the bulb. Agricultural technology should ensure rapid growth of the plant before the formation of the bulb.

Soil moisture is critical to onion development. For the seed to swell, the bulb to germinate, and the leaves to form, a large amount of moisture is needed. And watering onions at the beginning of their growth, in May-June, is very favorable for the harvest. Once the bulb has formed (late June, July), excess moisture is harmful. It delays ripening and can cause onions to grow, and such onions cannot be stored in winter.

Onions are among the cold-resistant plants. Its seeds can germinate at a temperature of 1-2 degrees Celsius. Onion seedlings tolerate short-term frosts of 1-2 degrees, and adult plants up to 6-7 degrees cold and below. Often in the spring you can see regrown bulbs that have lain in the soil all winter.

Onions are well stored in winter at a temperature of 1-3 degrees cold and do not die if it is briefly lowered to 5 degrees. Due to the poorly developed root system, onions especially need rich, well-fertilized and loose soil, easily accessible food, especially since they produce a harvest in a short period. But onions cannot tolerate high concentrations of nutrient salts. Therefore, it gives much better results if the required amount of fertilizer is applied not immediately, but several times during the growing season in the form of fertilizing.

Plant seeds usually germinate once they are in the ground at some depth. The very first shoot growing from the bud of the embryo must break through the soil. The first adventitious roots usually grow on this underground part of the stem. They can pull the base of the stem into the soil even deeper than it was originally immersed. Unlike rhizomes and tubers, bulbs have well-developed leaves, and the stem is very short and flat. He is called the "Donets".

At the top of the bottom, under the cover of scales, there is a bud from which an above-ground shoot grows. New “daughter” bulbs are formed from axillary buds located below the apical one. From each daughter bulb - “baby” - a new plant can grow.

What to do. Consider the external structure of the bulb.

• What is the outside of the bulb covered with?
• What does it matter?

What to do. Use a paring knife to cut the onion lengthwise.

What to watch. Examine the succulent scales—the leaves—closely pressed against each other.

How do internal scales differ from external scales?

What to do. Find and examine the stem-bottom, apical and lateral buds.

What to do. Consider the roots growing from the bottom.

• What are these roots called?
• What kind of root system do they form?

Prepare for the report. Draw a longitudinal section of the bulb and label its parts. Write down the signs that show the bulb is a shoot.

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Introduction: problem, goal, objectives, hypothesis

1. From the history of the bow

2. Structure of the bulb

3. Whoever undresses him sheds tears

4. Using a bow

5. Bulbous plants

6. Results, analysis, conclusions

Conclusion

Literature

Introduction

How often in life we ​​do not pay attention to familiar things. But if you look closely, you can learn a lot of interesting things.

For example, onions. By the way, why onion? Mom says that onions are healthy and often puts them in soups and salads. Grandma loves to bake pies with green onions. In our environment lessons, we also talked about the benefits of onions. What a benefit! There is a fire in the mouth, and a flood from the eyes. All onion riddles end like this:

Grandfather is sitting, dressed in a hundred fur coats,

Whoever undresses him sheds tears.

So we thought, why does an onion need an onion? And, in general, what is it? Botanists believe that a bulb is a stem with leaves, which nature has slightly changed at its whim. Does not look like it? It turns out that a bulb for plants is like a backpack with groceries for us. And, if not for the rich supply of sweet juices in the bulb, we would not be able to have green onions in early spring. There were a lot of questions. We started our own research.

Target: study of onion bulb.

Tasks:

1) find out the history of the appearance of onions on Earth;

2) find out how the bulb is structured inside;

3) observe the germination of the bulb under different conditions;

4) formalize the results of the study;

5) talk with experienced gardeners.

Object of study: bulb onions.

Subject of study: bulb - like an underground shoot.

Research hypothesis: if the bulb has a supply of nutrients, then under certain conditions (light, water, heat) it will germinate and sprout in the form of green feathers.

onion tear medicine plant

1. From the history of onions

We looked for information about onions in books and learned that the homeland of this culture is Central Asia, Iran and Afghanistan. Gradually, onions spread to nearby countries - India, China, Greece.

In Rus', this culture spread in the 12th - 13th centuries. When the ancient Egyptians built their pyramids, they wrote down on their walls how many onions the workers ate. He gave the builders strength and health. The value of onions is determined by the presence of many useful substances. For example, it contains more sugars than apples and pears. Even hot onions contain up to 14% sugars. About 500 types of onions are known. 10 types of onions are listed in the Red Book and are protected.

Onions come in different varieties. There are onions, batun, leeks, shallots, garlic, chives and others.

Onion most common. This bow changes its name three times. Its seeds are called “nigella onion”. From a seed as black as coal, a small onion grows. Onion sets. In the spring, the onion will be planted in the garden bed, it will become fat and look like a turnip. This is where the name came from - onion.

Onion- a perennial garden plant of the onion family, characterized by high bushiness. In the onion, the bulb is barely noticeable, but its long leaves (they are called feathers) are green and fresh from spring to autumn. China and the south of Eastern Siberia are considered its homeland. It has other names: fistula, sandy, tartar, winter, Chinese onion, odorless garlic.

Leek- a vegetable biennial spicy-aromatic plant, known and used by the ancient Egyptians, Greeks and Romans. The Eastern Mediterranean is considered its homeland. The Romans were especially fond of leeks. The famous Nero used this onion with butter, believing that the onion gave special strength and sound to his voice.

Shallot very similar to green onions. Its bulbs are small, elongated, and have a distinct taste and smell compared to regular onions. The taste is delicate and soft. Shallots are a high source of potassium and low in sodium.

Chives The good thing is that you can eat it in early spring, as soon as the snow melts. It can also be used for decorative purposes until late autumn. Used to create low borders. Onions - chives are an irreplaceable source of spring vitamins. The bulbs of this type are very small, collected in 15-20 pieces.

Garlic botanists describe it as a bulbous plant with a pungent taste

and a strong smell. Garlic does not spoil for a surprisingly long time and retains freshness and moisture for months, unlike other vegetables that dry out and decompose in just a few hours.

2. Bulb structure

We read in the encyclopedia:

"Loumkovitsa(lat. bъlbus) - a modified, usually underground shoot of plants with a thickened short flat stem (bottom) and overgrown fleshy or filmy colorless leaf bases (scales), storing water and nutrients, which also serve as an organ of vegetative propagation. Membranous bulbs are covered with common membranous scales (onion). In the axils of the scales there are buds from which above-ground shoots or daughter bulbs develop - kids»

And then they turned to biology teacher I.A. Silinskaya for help.

What is an onion? A house without windows or doors, a cleverly hidden bedroom, where baby onion buds, the rudiments of future sprouts, sleep for the time being between the juicy fleshy scales.

The outside walls of the onion children's bedroom are also covered with scales, only dry, golden ones. The thicker this golden coating, the longer the onion will be stored. The better the children's sleep.

3. “Whoever undresses him sheds tears”

They took the onions and began to peel them. But what happened? Tears immediately appeared in my eyes. Why? By cutting the onion with a knife, we disturbed the peace of the onion buds - the babies. The beast will fight for its cubs with claws and teeth. How can onions preserve their children? He has no claws or teeth. But the bow has a special, amazing weapon.

Arrows flew out of the cut onion. At the slightest damage to the bulb, tiny droplets of juice splash in all directions and get into the person’s eyes. We couldn’t see them - they were invisible, but we felt it - our eyes were stinging. We escaped with tears, but our eyes remained intact. But if carriers of diseases and harmful microbes get in the way of flying bow arrows, they will be in trouble.

Chemistry teacher Fedorova T.V. talked about the chemical composition of the onion. And we learned that onions emit a characteristic odor due to the presence of essential oils in it, including sulfur. Onion phytoncides kill microbes, streptococci - dysentery, diphtheria, tuberculosis bacilli, oral microflora, and have a beneficial effect on kidney function. Onions provide health benefits. In addition, onions contain protein, sucrose, maltose, fructose, polysaccharide, proteins, ash, and fats. Onions are rich in vitamins C, A, D, B1, B2, B6, E, PP; contains calcium, potassium, sodium, magnesium, phosphorus, iron.

Useful tips from our teacher

Before you start cutting onions, you should dip your knife in cold water so that the essential oils contained in onions do not irritate your eyes. And in order not to cry when peeling the onion, you should first hold it in cold water.

Onions are best preserved if they are hung in wreaths or in a net in a dry, ventilated place.

To remove the bitterness from chopped onions, scald them with boiling water and then keep them in cold water for a while.

To prevent the onion from burning, roll it in flour or sprinkle with granulated sugar before frying.

If half of the onion remains, it should be greased, then it will be well preserved.

4. Using a bow

Onions in folk medicine.

Onions have been used as a remedy in folk medicine in many countries since time immemorial. In Ancient Rus', onions, as in Ancient Rome, were considered a universal healing remedy for all diseases. Wise folk sayings and proverbs about this vegetable have reached our time:

"Onion - from seven ailments" (diseases).

“Onion and bath rule everything” (treat).

“He who eats onions is freed from torment.”

Ш Use fresh juice to remove warts, freckles, birthmarks, acne, lubricate ulcers on the oral mucosa, and place cotton swabs soaked in juice in the ears for purulent otitis media.

Ш Using a compress from an onion boiled in table vinegar, remove calluses. For headaches, it is recommended to apply cut onions to the temples and forehead.

Ш Fried onions in butter are taken orally for cough and chest pain.

Onions in cosmetology. Onion peels are also used for cosmetic purposes:

Ш Rinse your hair with a decoction that will give your hair a golden-straw hue, strengthen its roots, and prevent the formation of dandruff. This recipe was used by the Egyptians more than four thousand years ago.

Ш It is useful to rub onion juice with a decoction of burdock roots into the scalp under the hair if you have dandruff.

Ш Onion masks refresh and nourish the skin.

Ш The water in which onions were boiled is an excellent antibacterial agent. It's worth washing your face with.

We are so accustomed to onions that we sometimes forget that at any time of the year we have at our fingertips a cheap means of combating many diseases.

5. Bulbous plants

When planting tulips and daffodils in the spring, we noticed that they also have a bulb. Onions belong to the bulbous family.

Plants with a bulbous organ are called bulbous plants.

In spring, the flower bud and leaf buds develop into a flowering plant, taking advantage of the water and nutrient reserves stored in the fleshy leaves of the bulb. When the flower dies, the leaves continue to live and produce nutrients that are carried to the base of the leaves. They swell and turn into new bulbs, giving rise to new plants.

The genus of bulbous plants is quite large. Today it includes 600 species of perennial herbaceous plants.

Interestingly, our most popular onion has not been found growing wild.

Why do they say “onion grief”?

When a person cries, it means something has happened to him. But the reason why tears well up in the eyes is not in all cases associated with some kind of misfortune. When you peel or cut onions, tears flow. And the reason for this is “ onion grief" This phraseological unit is also known in other countries, only there it is slightly modified. The Germans, for example, use the phrase “onion tears.” People shed these tears over trifles. The expression “onion grief” also means minor troubles that you shouldn’t be too sad about.

So, we learned a lot about onions and bulbs, as well as their family. Now it is necessary to confirm the hypothesis in a practical way.

6.Organization of observations

Target: finding out under what conditions an onion bulb will germinate and sprout.

We prepared buckets of soil and planted 3 bulbs, creating different conditions for them (in the dark, in the shade and in the light).

We presented the results of observations in the table:

Thus, our observations of the bulbs confirmed the hypothesis: if the bulb contains a supply of nutrients, then under certain conditions it will germinate and produce a sprout in the form of a green feather. Light, water and warmth are necessary conditions for plant growth. Lack of light leads to unhealthy growth and color changes. The plant tries to catch the light, so the feathers are directed in different directions. The bulb that was exposed to the light had straight feathers.

But, if it weren’t for the supply of nutrients in the bulb that it accumulated after flowering, we would not have been able to have healthy green onions in the spring. Indeed, an onion bulb is a real pantry item.

Useful tips from grandmother Nikita Mironyuk Proskurina L.V. - an experienced gardener:

1. Select small bulbs for sowing.

2. Use earth, peat, sawdust as soil.

3. Before planting, soak the bulbs in warm water for 10 hours. This is necessary so that the bulb wakes up.

4. Cutting off the crown will slow down growth but increase yield.

6. Water generously at the beginning, but not often.

7. It is better not to pluck out the onion feathers, but to remove the entire onion.

This green vitamin bed on the windowsill will delight you all winter!

Conclusion

Onions are an amazing vegetable. We eat both green “feathers” and the bulbs themselves. Onions are a source of vitamins and a means of fighting diseases. Onions are a source of nutrients.

As a result of work on the project “Why do onions need an onion,” the goal was achieved, the problems were solved, the hypothesis was confirmed.

We made many discoveries for ourselves:

Sh got acquainted with the history of onions;

We learned about the family of bulbous plants;

Ш acquired practical experience in germinating bulbs;

Sh grew a small crop on their own;

Ш saved the family budget, because... green onions are not cheap in the store;

We learned how to collect the necessary information and organize it.

Literature

1. “Children’s Encyclopedia of Cyril and Methodius, 2007.”

2. Encyclopedia for children. Biology, publishing house "Avanta +", 1995, p. 246

3. I.A. Vinshu “The Land of Our Care” - Serov, State Unitary Enterprise “PO North”, p. 102

4. Jane Walker “Seeds, bulbs and spores”, M., Flamingo Publishing House, p. 18

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All about growing and forcing bulbous plants in Russia Litvinova Tatyana Aleksandrovna

Structure and types of bulbs

Structure and types of bulbs

The bulb is, in essence, the same shoot. It’s just that the stem in such a modified shoot corresponds to the bottom of the bulb, and the scales that are attached to the bottom correspond to the leaves. The thickest scales are located in the center of the bulb, the thinnest - almost transparent, beige - are located on the outside. The bulbs of different plants can have different shapes and sizes. In general, any bulb is structured in the same way as the bulb of the familiar onion.

With a vertical section of the bulb, we can see the embryo of the flower shoot at the very bottom, and around this embryo - the embryos of the leaves. The bulb contains such a supply of nutrients that they are enough for the plant to start growing at any time of the year! It is precisely because of winter flowering that I love bulbous plants so much!

How the bulb works can be understood by looking at the structure of the tulip bulb in Figure 1. Bulbs of other colors are very similar to it.

In addition to winter flowering, bulbous flowers differ from other flowers in that the number of leaves is predetermined by the number of their primordia in the bulb. This means that the leaves of the bulbous plants need to be plucked carefully - their supply is irreplaceable! I only trim off the dried leaves from my bulbous flowers.

The scales of the bulbs of some flowers lie tightly on top of each other - for example, hyacinths, and in some flowers the scales do not fit tightly to each other - for example, lilies.

Types of bulbs

1. Tunica (film): has concentric scales that span the inside of the bulb, with the edges of the scales usually either touching or fused together.

2. Semi-tunicular: has scales that do not completely cover the inside of the bulb, and the edges of the scales never grow together

3. Tiled: has very narrow scales, which only have one edge in contact with neighboring scales.

The number of scales in the bulb can vary - from one to several dozen.

Rice. 1. Structure of a tulip bulb

The structure of a tulip bulb in a horizontal section: 1 – remnant of last year’s peduncle; 2 – buds in the axils of storage scales; 3 4 – covering scales; 5 – peduncle; 6 – storage scales Structure of a tulip bulb in vertical section:1 – covering scales; 2 – leaf primordia; 3 – storage scales; 4 – buds storing scales; 5 – bud in the axil of the covering scales; 6 – kidney; 7 – bottom; 8 – root primordia; 9 – storage scales of a flower bud; 10 – flower bud; 11 – leaf bud buds

Scales are divided into grass roots and leaves. Lower scales are characterized by the presence of lower leaves. These leaves grow and turn into storage organs. Leaf scales serve as bases for above-ground leaves. By the end of the growing season, the above-ground part of the leaf dies off and the underground part grows - nutrients accumulate in it. The storage scales then become integumentary scales.

There are annual and perennial bulbs.

IN annual bulb ( for example, in a tulip) at the very base of the flower shoot, the embryos of the scales exist in the form of a bud. Next year a new bulb will grow from it - it is called a replacement bulb, and the old bulb will die.

IN perennial bulbs in the axils of the scales the rudiments of leaves will be laid, and from them the next year new scales will appear instead of the old ones. The bulb does not die entirely. Old scales will be pushed aside and become external.

In the axils of the scales are formed kids. These are lateral daughter bulbs that are separated from annual bulbs in the first year. They remain on the bottom in the form of a nest with common integumentary scales in perennial bulbs. Children are necessary for vegetative reproduction.