In different periods of the growing season, wheat makes different demands on heat. Its seeds begin to germinate at a temperature of 1 ... 2 ° C, but for friendly germination and emergence of seedlings, a higher temperature is needed. At a temperature of 14 ... 16 ° C (stage I of organogenesis), seedlings appear 7 ... 9 days after sowing. The sum of active temperatures for the period of sowing - seedlings is 116 ... 139 ° С. 13…15 days after full germination at a temperature of 12…15°C, tillering begins (II…III stages), it lasts 30…45 days, depending on the sowing time, temperature and humidity.

Winter wheat bushes in autumn and spring. Low air temperature (up to 6...10°C) with sufficient humidity, as well as increased cloudiness, delay the overall development of plants, but contribute to more intensive tillering. The tillering is significantly increased when nitrogen fertilizers are applied and when sown with large seeds. In favorable growing conditions, one plant forms 3 ... 5 stems.

In the transitional autumn-winter period, dry, clear and warm weather during the day (up to 10 ... 12 ° C) is most favorable for the development of winter wheat, with a decrease to negative temperatures at night, this contributes to greater accumulation of carbohydrates, hardening and better overwintering.

When the average daily air temperature drops to 4...5°C, the autumn growth of winter wheat stops. In spring, when the temperature rises to 5°C, the wheat begins to grow and additionally bush. For winter wheat, sharp fluctuations in temperature in early spring are very dangerous, when during the day it rises to + 10 ° C, and at night it drops to - 10 ° C. Winter wheat can withstand temperatures in the zone of the tillering node -16 ... - 18°C. Modern varieties are more resistant to low temperatures and are able to tolerate winter frosts up to -25 ... - 30 ° C in the presence of snow cover.

The booting (IV…VII stages) of winter wheat begins 25…35 days after spring regrowth, heading (VIII stage) – 30…35 days after booting. Flowering (stage IX) of wheat begins 2-3 days after heading and lasts about a week. The duration of formation, filling and maturation of grain (X…XII stages) is about 30…35 days, depending on weather conditions and characteristics of the variety. In rainy and cool weather, this period is lengthened, and in dry weather it is shortened.

The total sum of positive temperatures from sowing to full ripeness is 1850...2200°C. The length of the growing season (including winter) ranges from 275 to 350 days.

Winter wheat is quite heat-tolerant and drought-resistant, but less winter-hardy than winter rye. However, at too high temperatures (above 40 ° C), with a lack of moisture and dry winds, the normal process of photosynthesis is disturbed, transpiration increases, plant growth is inhibited, which prevents good grain filling. The effect of dry winds is stronger when they are long and are accompanied by a lack of moisture in the soil. Irrigation of wheat in arid regions reduces the negative effect of dry winds and prevents grain frailty.

Winter wheat makes better use of autumn and winter precipitation and consumes much more moisture than spring wheat. This is due to the fact that it has a longer growing season and forms a higher dry matter yield. Moisture consumption during the growing season is uneven and depends on age, intensity of growth and development, plant density, temperature, development of the root system and the presence of moisture in the soil.

In the phase of grain germination and emergence of seedlings, plants consume a relatively small amount of moisture. However, in order to get friendly and full-fledged seedlings, it is necessary to have at least 10 mm of productive moisture in the upper soil layer (0 ... 10 cm). As plants grow and develop, the need for moisture increases. For normal autumn tillering of winter wheat, it is necessary to have at least 30 mm of productive moisture in a soil layer of 0 ... 20 cm. wax ripeness of grain (up to 20%). The critical period in relation to moisture in winter wheat is the exit into the tube - earing. With a lack of moisture during this period, plant growth and the formation of leaf area are suspended, which leads to a violation of the differentiation of generative organs, the formation of a large number of barren flowers, the total accumulation of dry matter and plant height decrease, which leads to crop shortages.

During flowering and grain filling, the lack of moisture reduces the grain size of the ear, grain size and yield. By the beginning of the spring growing season, due to autumn, winter and spring precipitation, the soil is moistened to a depth of 50...80 cm, and in wet years - up to 150...200 cm, which creates favorable conditions for moisture supply. The root system of winter wheat penetrates to a depth of 1.5 ... 2.0 m, it uses water not only from the root layer, but also from deeper soil horizons.

A decrease in the growth rate of winter wheat, and sometimes the death of its crops, can also be observed during waterlogging, especially in late autumn and early spring, and in the northern regions - even in summer with heavy rainfall, when the soil is moistened to full saturation. At the same time, the air regime is disturbed, the conditions for microbiological processes and mineral nutrition worsen. With prolonged moisture, the growth rate decreases, the duration of the growing season increases, the root system may rot, resistance to lodging, yield and grain quality decrease.

Soil requirements.

Wheat is demanding on soils. They must be highly fertile, have a good structure, contain a sufficient amount of nutrients: nitrogen, phosphorus, potassium, etc. A neutral or slightly acidic (pH 6 - 7.5) reaction of the soil solution is favorable for wheat.

The root system, power and depth of its occurrence depend on the moisture content and mechanical composition of the soil. With sufficient soil moisture and a good structure of the plow horizon, it penetrates to a depth of 2 m. Therefore, the depth of the plow horizon, fertility and physical properties of the soil are of great importance for the favorable growth of wheat and, ultimately, for obtaining a high yield. On light sandy loamy soils, winter wheat grows poorly. Soils with a thick humus horizon, a high content of nutrients and good water-physical properties are most suitable for it. Highly fertile chernozem, dark chestnut, soddy-calcareous soils with a neutral or slightly acidic reaction (pH KCl 6.0 ... 7.5), with a humus content of at least 2.0 ... 2.5%, phosphorus and potassium not less than 150 mg per 1 kg of soil (according to Kirsanov). It can produce good yields on fertilized slightly podzolized, medium loamy and gray forest soils. On light sandy loams and drained peat bogs, as well as on acidic soils without their corresponding improvement, winter wheat does not work well. Liming, the use of organic and mineral fertilizers on acidic soils with a low content of organic matter are indispensable conditions for the cultivation of winter wheat.

Under it, it is better to allocate more fertile fields with a leveled relief. Lowered swampy areas are of little use for winter wheat, since it develops poorly on them and does not tolerate unfavorable wintering conditions. Winter wheat is rightly called a plant of cultivated agriculture. It gives high and stable yields with a high level of agricultural technology.

Requirements for batteries.

The consumption of mineral nutrition elements depends on their content in the soil in available forms, the intensity of plant development and the power of the root system, weather conditions and other factors. A decrease in the intensity of growth of winter wheat plants is often associated with an insufficient content of mineral nutrition elements - nitrogen, phosphorus, potassium, and, on some types of soil, microelements.

Nitrogen is one of the most important elements of plant nutrition, it regulates the growth of the vegetative mass, increases the protein and gluten content in the grain and affects the formation of the crop. It is part of the amino acids of simple and complex proteins, chlorophyll, some vitamins and enzymes. Both deficiency and excess of nitrogen adversely affect the growth and development of wheat plants and ultimately lead to a decrease in yield. With a lack of nitrogen, the rate of accumulation of dry matter and the formation of leaf area decrease, the leaves become pale green in color and die prematurely. Nitrogen starvation negatively affects the formation of crop structure elements, such as productive tillering, the number and weight of grains per ear, the weight of 1000 grains, and the protein and gluten content in the grain; technological properties and baking qualities deteriorate.

Excessive nitrogen nutrition sharply increases the growth of the vegetative mass, disrupts the ratio between the above-ground mass and the root system, lengthens the growing season, and reduces the resistance of plants to lodging and disease. Enhanced nitrogen nutrition and imbalance in other nutrients lead to crop shortages and a decrease in sowing qualities of seeds and technological properties of grain.

The consumption of nitrogen by winter wheat plants begins from the first days of life and continues until the end of grain filling. So, in the tillering phase, nitrogen consumption is 20...25%, during the period of heading - 50...55%, flowering - the beginning of wax ripeness - 10...15%, and by the middle of waxy ripeness - 5...10% of the maximum amount of nitrogen consumed. The lack of nitrogen in individual phases cannot be compensated by introducing it into subsequent phases. The greatest need for it is felt from the beginning of the exit into the tube to earing.

The maximum nitrogen content in plants falls on the period from germination to spring tillering and is 4.5 ... 6.0% per dry matter. With the growth and development of plants, the nitrogen content decreases and by the phase of full ripeness it is 1.0 ... 1.3%. In this regard, top dressing with nitrogen fertilizers in the early spring period is important for the formation of high yields and during the earing period to obtain grain with a high content of protein and gluten.

To obtain a given yield of winter wheat with high grain quality, it is necessary to maintain the optimal content of total nitrogen in the leaves: in the tillering phase 5.0 ... 5.5%, in the booting phase 4.5 ... 5.0 and in the heading phase 3.0 .. 4.0% on absolutely dry matter (ASD).

Phosphorus is a part of many organic compounds, enzymes and vitamins, takes part in energy metabolism. Many biochemical processes taking place in the body are associated with the provision of plants with phosphorus.

Increased availability of phosphorus reduces the negative effect of mobile forms of aluminum on acidic soddy-podzolic soils. The highest phosphorus content in winter wheat plants falls on the germination phase (1.0…1.5% per DIA), with growth and development, the phosphorus content noticeably decreases. The highest consumption of phosphorus falls on the phases of budding, earing and flowering. Insufficient supply of winter wheat plants with phosphorus delays the use of nitrogen, protein synthesis, slows down plant growth, which leads to a decrease in yield.

Signs of phosphorus starvation of plants are the appearance of a red-violet hue in the color of the leaves and their rapid death. Winter wheat has a low ability to extract phosphorus from the soil, which is in hard-to-reach forms.

Potassium improves the process of photosynthesis, carbohydrate and protein metabolism, the movement of carbohydrates in plants. Potassium starvation of plants increases the breakdown of proteins, which contributes to the development of various pathogenic fungi and bacteria. External signs of potassium starvation are browning of the edges of the leaves and the appearance of rusty spots on them.

The intake of potassium into plants begins with the germination phase and continues until flowering. Its maximum content in winter wheat plants (2.5…3.8%) falls on the initial phases; by the phase of full ripeness, the amount of potassium decreases to 0.8…1.0%. Potassium consumption is greatest during the bobbing, heading and flowering phases.

temperature requirements.

In different periods of vegetation, winter wheat makes different demands on temperature. During germination and tillering, the optimum temperature is from 12 to 14°C. Subsequently, dry, clear and warm weather is most favorable for the development of wheat: in the daytime 10–12°С with a decrease in temperature at night to 0°С and below. Such a period of temperatures contributes to good hardening of wheat, which increases its endurance in winter-spring conditions. For zoned varieties in the conditions of Belarus, the temperature limit below which winter wheat dies is -20°C. However, in the presence of snow cover, such a temperature is not fatal for it, since in the presence of snow cover, the temperature of the soil at the depth of the tillering node is higher than that of air. In the conditions of Belarus, the negative factors of overwintering of winter wheat include: snowfall on unfrozen soil, which usually causes dampening; frequent and prolonged thaws that contribute to the formation of an ice crust; severe frosts with insufficient snow cover, causing the death of plants from hypothermia, as well as early snow melting, followed by the return of cold weather, leading to the death of plants weakened by overwintering.

At the beginning of spring development for winter wheat, the most favorable temperature is from 12 to 15 ° C and above, however, temperatures above 25 ° C have a negative effect on plants in certain phases of their development. In the booting phase, a temperature of 15 - 16 ° C is required. During the heading and flowering period, wheat is more demanding of heat. The plant at this time needs about 18 - 20 ° C. At temperatures below -2°C, plants die or are severely damaged. Generative organs are especially sensitive to low temperatures during this period.

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07.05.2018

For the formation of high yields of winter wheat, tillering is important. In the 3-4 leaf phase, a thickening is formed on the underground part of the wheat stem, which is called the tillering node. The tillering potential of plants is programmed, first of all, by the force of development of the tillering node. This plant organ consists of several underground nodes close to each other. Under normal growing conditions, it is located at a depth of 1-3 cm. All parts of the future plant are located in the tillering node from the very beginning. It is the most important organ of winter wheat.

The centers of regeneration and neoplasms of organs is the meristem of tillering nodes with a supply of energy and active substances. When depleted, they cannot generate new tissues and organs. The death of a node due to adverse conditions or damage by pests leads to the destruction of the whole plant. In the event of the death of part or even all of the leaves, or damage to part of the root system with a living tillering node, the plant retains the possibility of further growth and development. Its growth cone and lateral buds remain intact; for a long time in the phase of autumn and spring tillering (before entering the tube) they are in the tillering node below the soil surface. This is an evolutionary natural adaptation of cereals to endure adverse conditions.

The number of stems on one plant can vary considerably. According to standard technology, it is 1-3 stems, and only on liquefied crops it can reach 10 or more. However, the potential for side shoot formation in winter wheat is extremely high. Productive tillering under the creation of appropriate living conditions can reach up to 100 ears and more. Wheat bushes with a feeding area of ​​30x70 cm produce up to 100 stems with a productivity of 100-120 g. And under artificial conditions, plants with more than 300 stems can be obtained. For example, in a special experiment, the variety Odessa 3 grew 334 shoots.

There are two opposing views on the ability of winter wheat to bush and the significance of this phenomenon for the crop. Some researchers consider tillering an important reserve for yield growth. Others argue that an increase in the number of shoots affects the decrease in yield, that is, they deny the advisability of tillering. In their opinion, winter wheat is characterized by asynchrony in the development of shoots, which leads to their reduction in the late growth phases. The tillering shoots preserved for harvesting are less productive compared to the main ones. In addition, secondary stems that do not produce grain use moisture, light, and nutrients unproductively.

The secondary role of tillering in the formation of the crop allowed scientists to come to the conclusion that it is expedient to develop varieties with a low tillering coefficient, a rapidly growing first (main) stem and an early reduction of lateral shoots, that is, predominantly single-stem ones. In order to achieve uniformity of the productive stem stand, in which there will be no competition between highly open multi-stem plants and underdeveloped single-stem plants, it is necessary to apply certain elements of the technology, in particular, to increase the seeding rate.

But if we approach this problem from the other side, we will find that at high seeding rates it is possible to influence only such an indicator of the crop structure as the density of productive stems. The yield potential of winter wheat is determined only by the density of crops. It is almost impossible to increase the tillering coefficient in such thickened agrophytocenoses. It is problematic to increase the elements of the productivity of the ear, especially the number of grains in the ear, and its mass, as a result of which the possibilities of controlling the crop structure are severely limited. Therefore, most scientists refute the concept of a single stem plant.

Thus, a bush should be formed from the seed, consisting of the main and two or three side stems with a well-developed secondary root system. With this development, the bush produces several productive stems that develop almost simultaneously. This is the most healthy and powerful type of bush, which is resistant to lodging and disease. It is important to prevent the formation of stems of the second and subsequent orders.

The first shoots - the main one and three of the buds of the first three true leaves - form spikes that are not inferior in performance to the main one. With a sufficient feeding area, the first 4-5 tillering shoots almost do not differ either in the size of the straw, or in the size of the ear, or in the number of spikelets and grains in them.

There is a lot of experimental data that proves the value of not only lateral productive shoots. According to the researchers, lateral shoots, which do not even form grains and are temporary competitors in the struggle for nutrients, light and moisture, have a positive effect on crop yields. They form an additional root system, which, after their death, works for the plant. The root system of the plant transfers water and nutrients through the tillering node to all shoots. Absorbing force, the power of the root system in the process of dropping part of the shoots is enhanced. Fewer shoots remain for the same size root system, which means that their best growth and development are ensured. With the help of shoots, the assimilating apparatus increases, more plastic substances accumulate, which later move to spike-bearing stems and increase their productivity.

Multi-stem plants have a better developed ground mass and root system, are more resistant to unfavorable growth conditions and are able to form higher productivity compared to underdeveloped single-stem plants. The shedding of individual shoots at the time of emergence into the tube in strongly bushy plants is not equivalent to the death of a whole weakly spreading plant with a high density of stems. The loss of plants creates sparseness and uneven placement of them and stems. The reduction of a part of the stems, on the contrary, contributes to the formation of a uniformly distributed stem stand, since their main part falls out in dense places. Therefore, tillering has a positive effect on the yield of winter wheat.

The intensity of tillering depends on many factors. First of all, these are those natural factors that are almost not amenable to human regulation, but have a primary influence on tillering. These include soil fertility, moisture availability, temperature conditions, lighting intensity, daylight hours, etc.

The tillering energy is strongly influenced by the duration of tillering, i.e., the time from the germination phase to the emergence into the tube. The continuation of the tillering phase contributes to the formation of more side shoots.

Winter wheat can have two tillering periods - autumn and spring, depending on the sowing time and other factors. In autumn, tillering continues until the average daily temperature drops to 2-3°C. The duration of autumn tillering under normal conditions is 25-30 days, spring - 30-35 days.

In the spring, tillering resumes with the beginning of the spring vegetation and continues until the start of the tube, when the average daily temperature rises to 10-12°C. With late sowing and the absence of autumn tillering, the stem density is formed due to spring tillering. It can be significantly enhanced by the use of morphoregulators (retardants) and the first nitrogen supply.

There is a widespread opinion that spring tillering almost does not produce productive stems, but this applies only to those crops where a high stem density was formed in autumn, or in conditions of low moisture reserves.

In plants that are well bushy from autumn, the root system will work in spring on autumn shoots, which take away the main part of the nutrients and, thus, limit spring tillering completely or weaken the development of spring shoots. In the absence of autumn shoots, all the force of growth and development of the plant is directed to the formation of strong, well-developed spring shoots, which can ensure the productivity of the colossus at the level of productivity of shoots formed in autumn. Of course, in order to fully realize the productivity of spring shoots, a technology adapted to specific meteorological conditions with constant monitoring throughout the spring-summer growing season is required. The main thing is to ensure the development of a high-yielding plant.

Evgenia Ivanova

During the growing season, the following phases of growth and development are noted in cereal crops: germination, tillering, tube formation, heading (or heading), flowering, filling and ripening. The beginning of the phase is considered the day when at least 10% of the plants enter it; the full phase is noted in the presence of the corresponding signs in 75% of plants. At winter crops, the first two stages of organogenesis and two phases under favorable conditions occur in the fall, the rest - in the spring and summer of the next year; in spring crops - in spring and summer in the year of sowing.

Swelling and germination of seeds precede the germination phase. In order for the seeds to germinate, they must swell, i.e. absorb a certain amount of water, which depends on their size and chemical composition. For example, rye change absorb 55...65% of water from their mass, wheat - 47...48, barley - 48..57, oats - 60...75, corn - 37...44, millet and sorghum - 25...38%. For the swelling of seeds of grain legumes, 100 ... 125% of water is required from their absolutely dry mass.

The water absorption is influenced by the temperature of the environment, the concentration of the soil solution, the structure and size of the grain. The most favorable temperature during the period of seed swelling is 10...21 °C. On soils with a high salt concentration, swelling and then germination are delayed. Mealy grains of wheat and small seeds absorb water faster than glassy and large grains, so the seed must be leveled to obtain friendly seedlings. Filmy grain swells more slowly than naked grain. When swelling in the seeds, biochemical and physiological processes occur. Under the influence of enzymes, complex chemical compounds (starch, proteins, fats, etc.) are converted into simple, soluble compounds. They become available for nourishment of the embryo and move into it through the scutellum.

D. N. Pryanishnikov found that the protein in the endosperm is cleaved to form amino acids, and a small amount of asparagine and glutamine. Nitrogenous substances, reacting with the breakdown products of carbohydrates, serve to synthesize new proteins in the growing embryo.

Having received nutrition, the embryo from a state of rest passes to active life. The seeds are starting to germinate. At this time, they need moisture, oxygen and certain temperature conditions. The minimum temperatures at which seeds of grain crops can germinate are as follows: for breads of the first group 1 ... 2 ° C (optimum - 15 ... 20 ° C), for breads of the second group 8 ... -25...30 C).

Under the climatic conditions of our country, when sowing at the optimal time, the temperature fluctuates in the range of 6...12 °C for the breads of the first group and 15...22 °C for the breads of the second group, although the optimum temperature is much higher. Temperatures above 30...35C adversely affect seed germination and may even cause their death.

Lack or excess of moisture, low or high temperatures, poor air access to the soil delay seed germination. Excessive soil moisture, deep planting of seeds, especially on heavy soils, and the formation of a crust on the soil surface make it difficult for air to reach seedlings, which sharply reduces seed germination and emergence.

seedlings- the first phase of growth and development. As the seeds swell, they begin to germinate. First, the germinal roots begin to grow, and then the stem shoot. Having broken through the family shell in naked grains, the stem appears near the shield; in filmy crops, it passes under the lemma and exits at the top of the grain, starting to break through to the soil surface. From above, it is covered with a thin transparent film in the form of a case called a coleoptile. Coleoptile - a modified primary vaginal leaf of a plant - protects the young stem and first leaf from mechanical damage during their growth in the soil. As soon as the stalk reaches the soil surface, under the influence of sunlight, the coleoptile stops growing and, under the pressure of the growing leaf, breaks, the first true leaf comes out. At the time of the release of the first green leaf in cereal crops, the germination phase is noted.

To grow high and stable yields, it is very important to get timely, friendly and full-fledged seedlings of optimal density. This can be achieved by establishing the correct seeding rate, using high quality seeds, improving agricultural practices and growing conditions. Plant density depends on field germination, seeds. Field germination - the number of emerging seedlings, expressed as a percentage of the number of germinating seeds sown. Field germination of seeds in farms of various zones of the Russian Federation ranges from 60 to 70% on average. With the observance of the technology of cultivation of grain crops, field germination increases significantly and reaches 70:45%. It has been established that a decrease in field germination by 1% leads to a decrease in grain yield by 1.5...2.0%.

The agronomic significance of the germination phase lies in the fact that when crops are thinned (poor-quality seeds, unfavorable conditions during the germination period), re-sowing is carried out in this phase. Later reseeding leads To yield reduction. Normal seedling density is the basis for a good crop yield.

In 10-14 days after germination, the plants form several leaves (usually 3, less often 4). Along with their growth, the root system develops. By the time 3...4 leaves are formed, the germinal roots branch out and penetrate the soil to a depth of 30...35 cm, the growth of the stem and leaves temporarily stops, and a new phase of plant development begins - tillering.

tillering- this formation ran from underground stem nodes. First, nodal roots develop from them, then lateral shoots that come to the surface of the soil and grow in the same way as the main stem. The upper node of the main stem, which is located at a depth of 1 ... 3 cm from the soil surface, where this process occurs, is called the tillering node. The tillering node is an important organ, its damage leads to a weakening of the growth and death of the plant. Simultaneously with the formation of lateral shoots, a secondary (nodal) root system is formed, which is located mainly in the surface layer.

The intensity of tillering depends on the growing conditions, species and varietal characteristics of grain crops. Under favorable conditions (optimal temperature and soil moisture), the tillering period is extended, and the number of shoots increases. Under normal conditions, winter crops form 3...6 shoots, spring crops - 2...3.

Distinguish between general and productive tillering. Under the general tillering understand the average number of stems that fall on one plant, regardless of the degree of their development. Productive bushiness - the average number of fruiting stems per plant. Productive tillering is of great practical importance; the yield largely depends on it. Stem shoots that formed inflorescences, but did not have time to form seeds before harvesting, are called undershoots, and shoots without inflorescences are called undercuts.

The dynamics of the formation of tillering shoots and nodal roots in grain crops is not the same. In rye and oats, tillering and rooting proceed simultaneously during the period of the appearance of the 3rd ... 4th leaf. In barley and wheat, tillering shoots appear before the beginning of rooting, tillering occurs during the appearance of the 3rd leaf, and rooting - 4 ... 5th leaf. In millet, tillering shoots are formed during the appearance of the 5th ... 6th leaf, in corn - on the 6th ... 7th and in sorghum - on the 7th ... 8th leaf. Nodal roots in these cultures begin to develop when the 3rd ... 4th leaf is formed. This largely explains the ability of cereals of the second group to better tolerate the lack of moisture in the initial and (except for corn) in subsequent periods of growth and development.

All parts of the future plant are placed in the tillering node, and at the same time it serves as a receptacle for reserve nutrients. The death of the tillering node always leads to the death of the plant. The tillering node lies at a depth of 2...3 cm; with a deeper occurrence, the resistance of grain crops to lodging increases, winter crops suffer less from winter-spring low temperatures.

The depth of the tillering node is strongly influenced by the depth of seed placement, seed treatment with retardants, temperature, light, soil type and variety. With a lack of light, the tillering node braids closer to the soil surface, at low temperatures, with deeper seed placement and when they are treated with retardants, the depth of the tillering node increases. Hard wheat varieties lay the tillering node deeper than soft wheat varieties.

The tillering of plants depends on temperature, availability of moisture, nutrients, sowing time, type and variety of plant. The tillering of the breads of the first group can take place at a temperature of about 5°C, but in these cases the tillering energy is weak. The most friendly tillering occurs at a temperature of 10 ... 15 C. At a higher temperature, the tillering period ends quickly and fewer shoots are formed.

In timely sown winter rye at optimal temperature and soil moisture, tillering occurs mainly in autumn, in winter wheat and triticale - in autumn and spring. Each plant can form from one to several productive stems, in winter crops they usually have 3 ... 6, in barley and oats - 2 ... 3, and in spring wheat - 1, rarely 2. The higher the productive tillering, the more grain yield per plant, but the highest yield per unit area is obtained with low tillering and optimal plant density.

There is no consensus in the literature about the significance of the tillering of grain breads. P. N. Konstantinov, A. I. Nosatovsky, P. P. Lukyanenko and other researchers consider tillering as an undesirable phenomenon, especially in arid regions. They believe that a lot of water and nutrients are spent on the formation of secondary stems, which worsens the supply of them to the main stems. At the same time, the yield from secondary stems is insufficient to compensate for the shortage of grain from the main stems. These scientists consider 1...2-stem plants to be the best type of spring crops for arid regions.

Other researchers (V. R. Williams, V. E. Pisarev, S. A. Muravyov, Ya. V. Gubanov and others) believe that with good tillering, due to the growth of the leaf surface, a larger amount of organic matter accumulates, which is used to form grains. Under favorable conditions, lateral stems give 30...50% of the grain yield, on sparse crops - up to 60...70%. However, strong tillering can lead to lodging, especially in a wet zone, to a decrease in yield and product quality.

Thickened crops lodging more, which reduces the photosynthetic activity of plants, worsens grain filling and increases losses during harvesting. The optimal density of productive stems for cereals is 500...600 plants per 1 sq.m., which provides a yield of 4...5 t/ha.

Exit to the handset characterized by the beginning of stem growth and the formation of generative organs of the plant. The beginning of the exit into the tube is considered such a state of plants, when stem nodes - tubercles are easily felt above the soil surface at a height of 3 ... 5 cm inside the leaf sheath of the main stem. During this period, the plant needs a good supply of moisture and nutrients, as generative organs are laid and intensive growth begins.

Stem growth begins with the elongation of the lower internode, located directly above the tillering node. Intensive growth of the first internode lasts 5...7 days, then the growth slows down and ends on the 10...15th day: The second internode begins to grow almost simultaneously. After the suspension of its growth, the third and subsequent internodes lengthen. Each internode grows with its lower part. The growth of internodes ends by the end of flowering - the beginning of grain filling.

In the phase of entry into the tube, the assimilating surface intensively grows. The leaf area increases throughout the entire booting phase, reaching a maximum in the heading or flowering phase. On normally developed crops of grain crops, the leaf area in this phase reaches 30...40 thousand hectares. m/ha, FP - 2.0...2.5 million square meters* days/ha, accumulates up to 50...60% of dry matter of the total mass for the entire growing season. This phase is characterized by intensive development of the root system, by the end of which the depth of penetration of the roots into the soil can reach 1.5 ... 2.5 m.

Heading, or heading, is characterized by the appearance of an inflorescence from the upper leaf sheath. Inflorescences appear first on the main shoots, after 2-3 days - on the side shoots. By The date of the onset of this phase can most reliably determine the precocity of varieties.

In this phase, leaves and stems grow intensively and an ear (panicle) is formed. Plants make high demands on growing conditions. The lack of moisture in the soil, dry and hot weather during this period lead to a disruption in the formation of generative organs and the formation of a large number of underdeveloped and sterile flowers in the ear.

Bloom in soddy crops, it occurs during or shortly after heading (heading). So, in barley, flowering takes place even before full heading, when the ear has not come out and the leaf sheath; for wheat - after 2...3 days, for rye - after 8...10 days, for triticale - after 7...12 days after heading.

According to the method of pollination, grain breads are divided into self-pollinated (wheat, barley, triticale, oats, millet, rice) and cross-pollinated (rye, buckwheat, corn, sorghum). Self-pollinating plants are pollinated mainly when flowers are closed with their pollen. In wheat, sometimes (in hot weather) the flowers open and cross (spontaneous) pollination can occur. In cross-pollinating plants, during flowering, with the help of swollen lodicula, the lemmas are moved apart and ripe anthers and stigmas of pistils appear. Pollen is carried by wind or insects, and pollination is best in warm, clear weather. Under unfavorable conditions during the flowering period, seed set decreases; in a crop such as rye, the grain size can reach 25 ... 30% or more, which causes a decrease in yield.

In spike crops (wheat, rye, triticale, barley), flowering begins from the middle part of the ear, in paniculate crops (oats, millet, sorghum) - from the top of the panicle.

Ripeness comes after flowering. The process of grain formation in bread N. N. Kuleshov divides into three periods: formation, filling and ripening. I. G. Sling divided the first period into two: the formation and formation of seeds. Seed formation - the period from fertilization to the appearance of a growth point, the seed is able to give a weak sprout, the weight of 1000 seeds is 1 ton, the duration of the period is 7 ... 9 days.

Seed formation continues until the final grain length is reached. By the end of the period, the differentiation of the embryo ends, the contents of the grain turn from watery into milky, starch grains appear in the endosperm, the color of the shell turns from white to green. Grain moisture 65...80%, weight of 1000 seeds 8...12g, period duration 5...8 days.

Filling - the period from the beginning of the deposition of starch in the endosperm until the termination of this process. The moisture content of the grain is reduced to 37...40%, the duration of the period is 20...25 days.

The filling period is divided into four phases:

1) watery state - the beginning of the formation of endosperm cells; dry matter is 2 ... 3% of the maximum amount; the duration of the phase is 6 days;

2) pre-milk state - the contents of the seed are watery with a milky tint; dry matter accumulates 10%; the duration of the phase is 6...7 days;

3) milky state - the grain contains a milky white liquid; dry matter content 50% of the mass of mature seed; phase duration 7...15 days;

4) pasty state - endosperm has the consistency of dough; dry matter content 85 ... 90% of the maximum amount; the duration of the phase is 4...5 days.

Maturation begins with the cessation of the flow of plastic substances. Grain moisture content is reduced to 18....12% and even up to 8%. The grain is ripe and suitable for sowing, technical and economic purposes, but the development of the seed is not yet complete.

The maturation period is divided into two phases:

1) waxy ripeness - the endosperm is waxy, elastic, the grain shell becomes yellow. Humidity drops to 30%. The duration of the phase is 3...6 days. In this phase, two-phase (separate) cleaning is started;

2) hard ripeness - the endosperm is hard, powdery or glassy at the break, the shell is dense, leathery, the color is typical. Humidity depending on the zone 8...22%. The duration of the phase is 3...5 days. In this phase, complex biochemical processes take place, after which a new and most important property of the seed appears - normal germination. Therefore, two more periods are additionally distinguished: post-harvest ripening and full ripeness.

During post-harvest ripening, the synthesis of high-molecular protein compounds ends, free fatty acids turn into fats, carbohydrate molecules become larger, and respiration fades. At the beginning of the period, seed germination is low, at the end it is normal. The duration of this period varies from several days to several months, depending on the characteristics of the culture and external conditions.

In the southern and southeastern regions of the country, crops of grain crops during the pouring period are exposed to the action of dry winds that occur under conditions of high temperature and low humidity. Under such conditions, grain filling stops, “fuse” or “capture” occurs, the grain becomes wrinkled, puny, unfulfilled, which leads to a sharp decrease in yield. The main means of combating dry winds are the expansion of field afforestation, the use of agricultural practices that contribute to the accumulation of moisture in the soil.

In conditions of rainy and warm weather, during the period of filling and maturation, “running off” (more often observed in wheat) may occur due to the leaching of soluble substances from the grain, in this case, the grain loses weight and its technological properties deteriorate.

In Western and Eastern Siberia, in some years, the ripening period is delayed and the crops fall under frost, as a result, the yield decreases, and low-quality frost grain is obtained. In these areas, to obtain higher yields of good quality grain, two-phase harvesting is used from the first half of wax ripeness, and early ripening varieties are also used.



All plants during the growing season from seed germination to the maturation of new seeds go through certain phases that are closely related to each other and successively replace each other. The onset of each phase is established by eye according to the external morphological features of the plant, which characterize the quantitative and qualitative changes occurring in a living organism. Such observations are called phenological. At each stage of growth and development, plants experience different needs for nutrition, moisture and other life factors. Therefore, knowledge of the growth phases makes it possible to monitor the state of crops and timely carry out the necessary agrotechnical measures aimed at meeting the needs of plants in one or another life factor.

In the process of development, grain crop plants successively go through the following phases: germination, tillering, tube formation, heading (or heading), flowering and ripening. In Western countries, another phenological Zadox scale has been adopted, which is a decimal code for the development of cereals. The entire cycle of plant development is divided into 10 main phases, which are numbered from 0 to 9. Each phase is divided into 10 microphases (Fig. 9). Such a classification is more preferable, since it makes it possible to more accurately determine the stage of plant development and carry out computer processing of the observation results. The beginning of the phase is noted when at least 10% of the plants enter it, and the full onset of the phase is noted when 75% of the plants have the corresponding signs.

The emergence of seedlings is preceded by swelling of the seeds and their germination. The rate of swelling of the sown grain depends on the humidity, temperature and aeration of the soil. Wheat and rye seeds require about 55% water by weight of dry grain to swell. For barley, this figure is 50, for oats - 65, for corn - 40, millet - 25. Moisture activates the activity of seed enzymes, the embryo comes out of dormancy and goes on to active life. The seeds are starting to germinate. First, germinal roots begin to grow. Their number depends on the type of plant. Wheat has 3 - 5 roots, rye - 4, barley 5 - 8, oats 3 - 4, bread 2 groups germinate with one root (Fig. 3.13).

Figure 3.12. Growth phases of winter wheat and stages of organogenesis according to Zadoks

Figure 3.13. Germination of cereals: 1 - rye; 2 - oats; 3 - corn; 4 - wheat; 5 - barley

Following the primary roots, the stem shoot begins to grow. For breads of the 1st group, the first leaf breaking through the soil layer is covered with a transparent cover - coleoptile, which protects the sprout from damage (Fig. 3.14-a). When it reaches the soil surface, the coleoptile stops growing, breaks and the first green leaf goes into the resulting crack (Fig. 3.14-b). The size of the coleoptile is limited, and therefore, when planted too deep, it often does not reach the soil surface. An unprotected leaf dies, or non-coleoptile entries become weakened.

In order to get friendly, uniform seedlings, it is necessary that the seeds be planted to the optimum depth, and the soil contains a sufficient amount of moisture and air (Fig. 3.14).

a

b

Figure 3.14. Germination of the first leaf and exit from the coleoptile

This is ensured by careful preparation of the soil. The sowing layer should be loose, granular, the seed bed dense and moist, the soil surface should be even.

Figure 3.15.. Shoots of winter wheat 10-20 stage according to Zadoks

The tillering of grain breads begins with the appearance of 3-4 leaves. It is fixed when the tips of the first leaves of lateral shoots emerge from the leaf sheaths of the main shoot. The growth of new shoots occurs due to the underground branching of the stem, and the node in which this process occurs is called tillering node Secondary (nodal roots) begin to form from the tillering node, and a bush consisting of several stems is formed on the soil surface (Fig. 12).

The number of stems (shoots) that form a plant is called general tillering. They also distinguish productive tillering- the number of stems on one plant, which gave ripened grain. Stem shoots on which ears (panicles) were formed, but the grain did not have time to ripen, are called fitting, and shoots without inflorescences - seated. Fitting and podsed are undesirable in crops, as they consume moisture with batteries and make harvesting difficult.

Figure 3.16. Winter wheat tillering: a- grain; b- primary roots; v- stem shoot; G- lateral shoots from the germinal node; d- tillering node; e- nodal roots; well- main stem h- side shoots

The degree of bushiness of cereals is primarily due to the biological characteristics of the species and variety. In addition, tillering depends on the area of ​​plant nutrition, soil moisture, time and depth of sowing, fertility and quality of tillage, temperature, lighting. On fertile soils and with high agricultural technology, tillering proceeds more vigorously. With thickened sowing and deep seeding, the plants bush worse (Fig. 3.17).

With a lack of moisture, tillering does not occur, the secondary root system is not formed, which leads to a sharp decrease in yield. A factor holding back tillering may be a lack of nitrogen in the soil.

Figure 3.17. Influence of sowing depth on the development of wheat plants

If the tillering node dies, all plants die. The tillering node in winter crops is especially endangered, therefore its preservation from unfavorable wintering conditions is the main task of the autumn and winter period. If the tillering node is preserved, shoots and roots that died in winter can recover from it.

The exit into the tube (bubbling) is noted when the upper node of the main stem shoot rises 5 cm above the soil surface (Fig. 14). At this height, you can feel it with your fingers.

Tube-making is a very important stage in the development of grain breads. At this time, the vegetative mass is intensively growing - straw, leaves, roots. Plants experience an increased need for moisture and nutrients. This period is critical, therefore, the creation of favorable conditions for plant growth during the booting period largely determines the size of the grain yield.

Figure 3.18. Beginning of bobbing and bobbing of wheat

Heading (heading) (Fig. 3.19) begins with the appearance of the upper leaf of 1/3 of the ear (panicle) from the leaf sheath. In this phase, plants are also very demanding on nutrition and moisture conditions. In dry, hot weather, the formation of flower organs may be disrupted, which will lead to a deterioration in the grain content of ears (panicles). Cold, rainy weather during the heading period extends the period of this phase, and, consequently, extends the time of maturation and harvesting.

Figure 3.19. earing of wheat

Flowering (Fig. 3.20) in most cereals occurs after heading (in barley it sometimes happens before heading). By the nature of flowering, cereals are divided into self-pollinating (barley, wheat, oats, millet, rice) and cross-pollinating (rye, corn, sorghum). In spike crops (wheat, rye, barley), flowering begins from the middle part of the spike, then spreading up and down. It is in the middle part of the ear that the largest grains are formed.

Panicled breads (millet, oats, sorghum, rice) bloom from the top of the panicle. The duration of the flowering phase is different for different crops. In wheat, for example, the flowering of one ear lasts 3-5 days, and the entire field 6-8 days. This period can be longer in cold, rainy weather and shorter in hot and dry weather. Extreme weather conditions adversely affect the fertilization of cross-pollinated crops. With incomplete pollination, a through-grain is observed.

Figure 3.20. wheat blossom

After flowering and fertilization, the growth of the stem of leaves and roots practically stops. The plastic substances formed by this time are used for the formation and filling of grains. At this time, it is very important to keep the leaves from being affected by diseases and prolong their functioning. This contributes to the formation of larger grains of high quality.

Grain formation and maturation. The process of grain formation includes three stages - the formation, filling and ripening of grain.

The formation of the grain begins soon after fertilization. The embryo is formed first, followed by the endosperm (Fig. 3.21). For 10 - 12 days, the grain grows to its final length.

Figure 3.21. Formation and filling of grains

Her content is in gelatinous liquid state, growth in length stops, filling begins. The thickness and width of the grain increases, the internal content enters the phase dairy, and then pasty states. By the end of the filling, the moisture content of the grain decreases to 40%. At this time, the flow of plastic substances to the grain stops, it proceeds to maturation.

Ripening is divided into 2 stages: phase wax ripeness and phase full ripeness(fig.3.22). At the beginning of wax ripeness, the grain completely loses its green color, the contents of the grain are not squeezed out, but easily roll into a ball. In the middle of wax ripeness, the moisture content of the grain drops to 35 - 25%, the endosperm of the grain can be cut with a fingernail. By the end of wax ripeness, when pressing with a fingernail, a trace remains on the grain, but it is no longer possible to cut the grain.

Figure 3.22. Stages of wheat ripening: milky, waxy and full ripeness

Mowing bread into rolls during separate harvesting begins in the middle (rye - at the end) of wax ripeness (Fig. 3.23).

In the phase of full ripeness, the humidity in the grain decreases to 17 - 16%, it is easily threshed from the ears, but does not crumble yet. The endosperm is hard, mealy or glassy at the break. At this time, single-phase harvesting of bread is carried out (Fig. 3.24).

Figure 3.23. Windrow mowing

If harvesting is delayed (overdue), grain losses are inevitable due to shedding.

Grain harvested at full ripeness is not yet physiologically mature and may have reduced germination. Post-harvest ripening can continue for another 3 weeks to 2 months. This property must be taken into account when using freshly harvested seeds of winter crops for sowing.

During the period of filling and ripening of grain, phenomena occur that cause disturbances in the normal process of plant development.

Figure 3.24. Single phase cleaning

lodging grains (Fig. 3.25) occurs in thickened crops with an excess of nitrogen nutrition and moisture, as a result of a downpour, hail of a strong wind. Plants that have fallen down are less lit, and fungal diseases can develop on them. At the same time, the outflow of assimilants into the grain decreases, it is formed small, the quality is low.

fuse plants occurs during intense heat and dry winds, when the stomata lose their ability to close. At the same time, moisture evaporates so quickly that the roots do not have time to supply it to the leaves, and it is sucked out of the inflorescences. A similar phenomenon also occurs when capture plants, which is associated with a lack of moisture in the soil (and not heat only). Often the fuse and seizure happen at the same time. As a result, the grain is formed small, puny with a small amount of starch.

Figure 3.25. Fallen crops of wheat

Objective: To study the growth phases of grain breads on the example of winter wheat

Materials and equipment: Preserved plant specimens, reference literature, posters and drawings.

For the successful cultivation of winter wheat, it is necessary to understand its features, adhere to the basic rules for care and sowing, observe the sowing dates, and also study all phases of crop development.

History of occurrence and distribution

Winter wheat has been grown for a long time in Russia. Where it came from and how it appeared, no one can say. One thing is known - this ancient type of cereal was one of the first mastered by man. The most ancient grains of winter wheat were found by archaeologists in Switzerland and Hungary.

From time immemorial, our ancestors have been growing cereals not only for personal needs, but also for the exchange of goods, and later for trade.

Now winter wheat is the most common crop in the world. Huge areas of land are allocated for its cultivation. There are about 250 varieties of it and there are several thousand varieties. Thanks to the efforts of breeders, winter wheat is moving further north and “capturing” new territories.

The main crops are located in Eurasia and America (North and South), or rather on the territory:

• France;
• Great Britain;
• Russia;
• Italy;
• Spain;
• Romania;
• China;
• India;
• Turkey;
• Canada;
• Australia.

To a lesser extent, wheat is grown in Africa - South Africa, Egypt, Ethiopia, Zimbabwe, Kenya and Oceania. Its wide distribution in different climatic zones is explained by a huge selection of varieties, as well as good adaptive ability.

In Russia, wheat is mostly grown in the North Caucasus District, the Central Black Earth Region and the Volga Region. However, the area of ​​its distribution is much wider - from the Tyumen to the Leningrad region.

National economic importance

Why is so much space devoted to this particular culture? Winter wheat is valued for its nutritional qualities. The composition of the grain meets all the necessary requirements to meet human needs. It has:

• protein;
• starch;
• fats;
• ash substances;
• vitamins of group B, PP, E;
• provitamins, that is, the precursors of vitamins A and D - carotene and ergosterol.

The calorie content of 100 g of wheat bread made from premium flour is 250 kcal, the calorie content of a piece of fatty meat (pork) of the same weight is 240 kcal.

How to use:

• For the production of flour for bread and bakery products, since winter wheat is mainly a "soft" crop. The highest quality flour is obtained from it, the fiber content of which is at least 28%. Bread made from wheat flour is tasty and nutritious.
• For confectionery production and to a lesser extent for pasta. To make high-quality pasta, on the contrary, durum wheat flour is required.
• For the manufacture of concentrated feed, wheat bran for all types of agricultural animals. Straw in crushed form, sometimes flavored with molasses, fed to cattle.
• Good material for barn bedding. In early spring, winter wheat is used as green fodder.
• For crop rotation. It is a good predecessor for other plants.
• In the processing industry. Alcohol, starch, dextrin and other substances are obtained from grain. Straw is used for the production of paper, mats, household items.

What is the difference between winter wheat and spring wheat?

The main differences between the forms of wheat:

• Winter crops are more demanding on soil and moisture. For good rooting, seeds are sown in fertile soil rich in macro- and microelements. With a lack of minerals, the yield decreases.
  The following types of soils are most suitable for its cultivation - chernozems, chestnut and slightly podzolic. Spring varieties are very sensitive to increased soil acidity, but more drought-resistant. Winter wheat makes maximum use of autumn and spring precipitation, which provides it with a high yield compared to spring wheat.
• Sowing time. Spring wheat varieties are sown in early spring, while winter crops are planted before winter (hence the name itself). Depending on the region, the sowing campaign starts from the end of summer and ends in October.

Morphological features

Winter wheat is an annual member of the bluegrass family. It is an upright cereal plant that propagates by caryopses. The culture has a fibrous root system located close to the soil surface, but the roots can penetrate 120-200 cm deep.

The stem-straw is round in section, hollow inside. It is divided along the entire length by nodes - ring-shaped thickenings into 5-6 internodes. The length of each increases as the plant grows. Stem thickness varies. It is smallest in the upper part, largest in the middle. Lateral shoots emerge from underground stem nodes.

The leaves are long, lanceolate with parallel veins. The number of leaves and their size depends on a number of factors - soil fertility, weather conditions, variety.

Winter leaves are of two types:

• basal leaves are formed from underground nodes;
• stem - on the aerial part of the plant - one leaf departs from the node, from below it is twisted into a tube and covers part of the stem.

The inflorescence is an ear, which consists of a spike rod, which is a continuation of the stem, and individual spikelets. Flowering comes from the center and spreads simultaneously up and down. The plant is self-pollinating. In cloudy weather, flowering is closed, in sunny weather it is open. After flowering, fruits are formed on the ears - bare grains.

Biological features

Winter is one of the most whimsical crops to weather conditions and external factors - soil, temperature, light. In some years, with weather anomalies, most of the crops may die.

Light

She belongs to the plants of a long day, she needs a lot of light. Thanks to photosynthesis, which takes place only under the sun's rays, nutrients accumulate in it. With the optimal amount of light, the plant bushes, the leaves are painted green. The following signs signal a lack of sunlight:

• growth of the lower internode;
• a tillering leaf is formed in the lower part, which worsens the winter hardiness of the plant;
• with a lack of light in the spring - the wheat stretches and lodges;
• during the period of ripening and filling of grain, an insufficient amount of light leads to a deterioration in the quality of the crop. This is usually seen in dense plantings.

Temperature

For a plant in certain periods of growth, a different temperature range is required. In general, winter wheat is a moderately hardy crop that can withstand temperatures down to -25°C if there is snow cover. In the absence of snow, the sprouts die already at 16-18°C of frost.

Seeds germinate at a temperature of 1-2°C above zero, but 12-15°C of heat is considered optimal for normal growth. Sowing starts when the average daily air temperature is within 14-17°C.

Plants that have had time to grow well (to form 2-4 shoots) are distinguished by a high rate of frost resistance. In overgrown ones, which managed to grow 5-6 shoots in the fall, frost resistance decreases. Often they do not survive the winter - they die or are damaged.

In the spring, wheat growth resumes. During this period, the optimum temperature is 12-15°C of heat. If the thermometer steadily creeps up and exceeds + 25 ° C, then this will negatively affect the growth phases.

Slightly above 15-16°C the plant is required when stemming. However, frosts (minus 7-9°C) damage the main stem and the plant dies.

During the flowering period, it is enough that the temperature is in the range of 18-20 ° C. At higher - 35-40°C and low air humidity, the grain becomes smaller and becomes puny. The optimal temperature for filling grain is 22-25°C.

Moisture

The plant is demanding on water throughout the growing season. But its consumption is uneven and depends on the growth phase, climatic conditions and planting density. During the period of seed germination and emergence of seedlings, a large amount of moisture is needed. Otherwise, landings will be rare.

Productive tillering is also negatively affected by the lack of water in the soil during the tillering period. The stalk period or tube emergence is critical in relation to moisture. With its deficiency, the granularity of the ear decreases, which, in turn, leads to a decrease in crop volumes. On the other hand, with prolonged moisture, plant growth is inhibited.

Development phases of winter wheat

The following growth phases of winter wheat are distinguished:

• Emergence of shoots. Seed germination is most intensively observed at a temperature of 20-25°C. In this case, seedlings appear on the 7-9th day. But for a more friendly appearance of sprouts, a lower temperature is required - 12-17 ° C of heat.
  Thus, the duration of the germination phase is extended by 15-25 days under normal conditions. With later sowing, the plant manages to grow 1-3 leaves before winter. In spring, the germination phase will continue, but its duration, taking into account the period of winter dormancy, increases to 100-150 days.
  The main agrotechnical task of specialists is to increase seed germination up to 80-90%. According to statistics, in most farms this figure is at the level of 50-70%, that is, no more than half of the planted seeds germinate.
• tillering. This is a biological feature of cereal crops, that is, the plant has lateral sprouts and nodal roots. Wheat bushes both in autumn and in spring. This process begins after the formation of the 3-4th leaf. With a decrease in temperature to 6-10 ° C of heat, sufficient humidity and cloudiness, plant growth slows down, but it begins to bush more intensively.
  The tillering is also positively affected by the application of nitrogen fertilizers and the size of the seeds during sowing - the larger they are, the better the plant will bush. Under favorable conditions, one plant forms 3-5 stems. The tillering node is the main organ. When it is damaged, the plant dies.
• Stalking (exit to the tube). The formation of the first stem node, which occurs 25-35 days after the start of spring growth, is considered to be the beginning of the tube entry or stemming phase. It is located at a height of 2-5 cm from the soil surface, but it must be borne in mind that cold and cloudy weather inhibits the growth of the plant.
• Heading. 30 days after entering the tube, earing begins - the exit of the ear from the sheath of the upper leaf. The intensity of this phase depends on the amount of moisture and nutrients in the soil. The same period is most favorable for the treatment of crops with fungicides in order to prevent the development of various diseases.
• Bloom. In 2-3 days after earing, winter wheat blooms. Flowering time is about 1 week.
• Maturation. This is the formation and filling of grain, the duration of which largely depends on the variety and weather conditions. Cool and rainy weather increases it, while dry weather reduces it.

Varieties of winter wheat

When choosing a particular variety for a particular region, take into account:

• winter hardiness;
• drought resistance;
• exactingness to the type of soil;
• immunity to diseases;
• productivity.

Winter wheat of a few durum varieties is grown only in the North Caucasus and the Lower Volga region. Soft varieties are common throughout Russia.

Suitable for the North Caucasus region:

• Shestopolavka;
• Kherson bezostaya;
• Jubilee 75 and 105;
• Podolyanka and others.

For the Northwestern District:

• Astron;
• Galina;
• Zentos;
• Mironovskaya anniversary;
• Toras.

For the Central region:

• Angelina;
• Bezenchukskaya 616;
• Nemchinovskaya 17, 24 and 57;
• Moscow 40, 56;
• Dawn.

Suitable for the Volga-Vyatka region:

• Bashkirskaya 10;
• Helot;
• Kazanskaya 285 and 560;
• Amber 50.

In the Central Black Earth region grow:

• Scarlet Dawn;
• Antonovka;
• Belgorodskaya 12, 16;
• Chernozemka 88 and 115;
• Chornyava and others.

In the Middle Volga region:

• Basis;
• Volzhskaya 16;
• Kharkovskaya 92;
• Tarasovskaya 70 and others;

For the Nizhnevolzhsky are:

• Aelita;
• Bulgun;
• Rostovchanka 3, 5, 7;
• Smuglyanka and others.

In the Ural region they sow:

• Bashkirskaya 10;
• Volzhskaya K;
• Kalach 60;
• Pearl of the Volga region and others;

In the West Siberian region:

• Volzhskaya K;
• Volzhskaya C 3;
• Harvest of Altai;
• Zimushka;
• Omskaya 4, 5;
• Novosibirsk 32.

In the East Siberian District grow:

• Novosibirskaya 2, 3, 40 and 51;
• Omsk Winter;
• Priirtyshskaya.

Wheat is also grown in the Far East:

• Moscow 39;
• Omsk Winter.

The variety of winter wheat "Scepter" is intended for cultivation throughout Russia, with the exception of the northern district - these are the Arkhangelsk and Murmansk regions, the Republic of Karelia and Komi.

Seeding dates and rates

The sowing campaign in the regions starts at different times. So, in the northern regions, wheat is sown starting from the 1st decade of August, and a little later (from the 2nd decade of August) they start sowing in the Central region. At the beginning of autumn - in the Black Earth region and the southern regions of Russia. In the North Caucasus, sowing is carried out until mid-October.

Also, experts calculate the seeding rate of grain separately for each region. On average, for 1 ha, the norm is 2.7-5.7 million seeds.

Seeding technology

The technology for sowing winter wheat includes several stages:

1. Choosing a place for sowing, taking into account crop rotation. The best forerunners for it are vegetables and perennial legumes, maize for silage, pulses, and black or bare fallow.
2. Soil cultivation and fertilization. Organic and mineral fertilizers are applied, special attention is paid to nitrogen-containing dressings.
3. Preparing seeds for sowing. Quality seeds are selected with a germination rate of at least 92%. They are pickled to increase germination and protection against various pathogens. To increase the resistance of plants to adverse conditions, microfertilizers are used.
4. Sowing. It is carried out in three ways:
   • narrow row- with row spacing of 7-8 cm;
   • solid private- leaving a distance between rows of 15 cm;
   • cross method, but it is practically not used.

The seeding depth depends on the type of soil. On heavy loamy and clayey soils, this is 3–4 cm. On light, sandy, arid soils, the embedment depth is 7–8 cm.

Crop care and harvest

Crop care involves 3 procedures:

1. Post-sowing rolling. The method is not used in rain or on clay soils. It helps improve seed-to-ground contact, reduces moisture loss, and promotes more uniform seedling emergence.
2. Early spring harrowing. It is necessary for loosening the soil and preventing the germination of weeds.
3. Crop protection. In the spring, seedlings are fed with nitrogen fertilizers, as well as trace elements. For each phase, specially designed industrial formulations are used. If the field is littered with weeds, then herbicide treatment is carried out from the beginning of tillering to the booting phase.

Harvesting of winter wheat is carried out during the period of full grain maturity (wax ripeness). Direct combining is usually used as it minimizes grain loss. The maximum cleaning time is 10 days.

However, if the field is littered, then separate collection is used. The moisture content of the grain in this case should be within 30%, which will help to avoid severe shedding. And also this method is used if the wheat has grown thick and high.

In this video, a leading practitioner talks about growing winter wheat:

Diseases, pests and prevention

• ascochitosis;
• powdery mildew;
• fusarium spike and fusarium root rot;
• snow mold;
• brown rust;
• ophiodisease root rot;
• septoria leaf and spike;
• hard, dusty and stem smut.

Of the pests, the most harmful are:

• grain beetles;
• bread beetle-kuzka;
• larvae of the Hessian fly (mosquito) and the individuals themselves;
• cereal flies;
• bread drinker.

To combat adversity, special compounds are used. All processing activities are carried out at the sowing stage. If the number of insects exceeds the allowable rate, then the fields are re-treated with insecticides. To reduce the negative impact on the plant, Aminokat 10 or 30% is used in parallel with them.

Favorable and unfavorable factors

There are a number of factors that affect the yield of winter wheat, both positively and negatively.

Yield increase

Yield can be improved by following these guidelines:

• alternation of crop rotation, selection of the right predecessors;
• application of optimal doses of mineral and organic fertilizers;
• high-quality tillage before sowing;
• the right variety;
• timely treatment of plants from pests and diseases.

Yield decline

Several factors negatively affect the yield:

• biological- the use of varieties that do not have immunity to diseases and pests, prone to lodging and shedding;
• agronomic- incorrectly selected variety for a certain region, errors in the timing of sowing and harvesting;
• technical- design flaws of machines, which entails poor-quality plowing, harrowing of the land or grain harvesting;
• other factors- most of the crop can be lost if stored improperly, and also if the grain is infected with a pest.

Storage conditions

When creating optimal storage conditions, almost the entire crop of winter wheat can be stored without loss of grain quality. To minimize losses, the grain must be dried and its moisture content should not exceed 12%. Store it at +12°C. Regularly checked for the presence of microorganisms and pests.

Winter wheat is a crop that has become widespread not only in the food industry, but also in many other industries. However, a rich harvest can only be obtained with proper care and following all the recommendations for the cultivation of wheat.

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