What does the plant lack? Deficiency and excess of nutrients. Plant mineral nutrition: basic elements and functions of various elements for plants Conditionally necessary nutrients for plants
Tatiana Rudakova
The main substances that make up the protoplasm of cells (it is in them that the most important biochemical and physiological processes for plant life occur) are proteins. Proteins are composed of carbon, oxygen, hydrogen, nitrogen, phosphorus, sulfur, iron and other elements. Microelements are present in plants in extremely small quantities: manganese, copper, zinc, molybdenum, boron, etc.
Plants obtain carbon from two sources: carbon dioxide from the air during photosynthesis and from organic matter in the soil.
Oxygen enters plants from the air during their respiration and, partially, from water from the soil.
Plants obtain nitrogen, potassium, phosphorus, iron, sulfur and other elements from the soil, where they are found in the form of mineral salts and are part of organic substances (amino acids, nucleic acids and vitamins). Through roots, plants absorb from the soil mainly ions of mineral salts, as well as some waste products of soil microorganisms and root secretions of other plants. The absorbed compounds of nitrogen, phosphorus and sulfur interact with the products of photosynthesis flowing from the leaves to form amino acids, nucleotides and other organic compounds. Through the vessels of the plant, elements in the form of ions (potassium, calcium, magnesium, phosphorus) or organic molecules (nitrogen, sulfur) move into the leaves and stems as a result of root pressure and transpiration. The root also synthesizes alkaloids (for example, nicotine), growth hormones (kinins, gibberellins) and other physiologically active substances. The roots also secrete auxins and other substances that stimulate plant growth.
The bulk of the chemical elements that plants need for nutrition are found in the soil in insoluble compounds, and therefore are not available to plants for absorption. Only a small part of the substances containing nutrients can be dissolved in water or weak acids and absorbed by plants. Insoluble nutrients take on an accessible form under the influence of soil microorganisms. Microorganisms also secrete antibiotics, vitamins and other substances beneficial to plants.
Macroelements are elements that plants need in significant quantities; their content in a plant reaches 0.1 - 5%.
Macroelements include nitrogen, potassium, phosphorus, sulfur, calcium, magnesium. Nitrogen
(N) is part of the amino acids that make up protein molecules. It is also part of chlorophyll, which is involved in plant photosynthesis, and enzymes. Nitrogen nutrition affects the growth and development of plants; with its deficiency, plants poorly develop green mass, branch poorly, their leaves become smaller and quickly turn yellow, flowers do not open, dry out and fall off.
Nitric and nitrous acid salts, ammonium, and carbamide (urea) can serve as a source of nitrogen for plant nutrition. Potassium
(K) in plants is in ionic form and is not part of the organic compounds of the cell. Potassium helps plants absorb carbon dioxide from the air and promotes the movement of carbohydrates in the plant; It is easier to tolerate drought because it retains water in the plant. With insufficient potassium nutrition, the plant is more quickly affected by various diseases. Potassium deficiency causes a weakening of the activity of certain enzymes, which leads to disturbances in the protein and water metabolism of the plant. Externally, signs of potassium starvation are manifested in the fact that old leaves turn yellow prematurely, starting from the edges, then the edges of the leaves turn brown and die. The absorption of potassium by a plant directly depends on the growth of the root mass: the higher it is, the more potassium the plant absorbs.
Potash mineral fertilizers include potassium chloride and potassium sulfate. Phosphorus
(P) is part of nucleoproteins, the main component of the cell nucleus. Phosphorus accelerates the development of crops, increases the yield of flower products, and allows plants to quickly adapt to low temperatures.
Phosphoric mineral fertilizers include superphosphate, phosphate rock, orthophosphoric acid salts. It is only necessary to take into account that in a neutral and alkaline environment, slightly soluble salts are formed, the phosphorus of which is inaccessible to plants. Sulfur
(S) is part of proteins, enzymes, and other organic compounds of plant cells. With a lack of sulfur, young leaves uniformly turn yellow and the veins become purple. Older leaves gradually lose their green color.
Special sulfur fertilizers are usually not applied, since it is contained in superphosphate, potassium sulfate, and manure.(Ca) is needed by both above-ground organs and plant roots. Its role is associated with plant photosynthesis and the development of the root system (with a lack of calcium, the roots thicken, lateral roots and root hairs do not form). Calcium deficiency appears at the ends of the shoots. Young leaves become lighter and light yellow spots appear on them. The edges of the leaves bend down, taking on the appearance of an umbrella. With severe calcium deficiency, the shoot tip dies.
Magnesium(Mg) is part of chlorophyll and activates the enzyme that converts carbon dioxide during photosynthesis. Participates in energy transfer reactions.
Signs of magnesium deficiency begin to appear on the lower leaves, then spread to the upper leaves. With a deficiency of this element, chlorosis has a characteristic appearance: at the edges of the leaf and between its veins, the green color changes not only to yellow, but also to red and purple. The veins and adjacent areas remain green. In this case, the leaves often bend dome-shaped, since the tips and edges of the leaf are bent.
Magnesium fertilizer is a preparation Kalimag.
There are a large number of fertilizers on the macrofertilizer market, which can be very difficult to understand and choose something suitable. Qualitatively, all fertilizers differ in the chemical composition of their components, that is, in how quickly substances containing nutrients are absorbed by plants. It is worth giving preference to those drugs that contain soluble salts: monopotassium phosphate, monoammonium phosphate, potassium sulfate, potassium nitrate.
Microelements in the plant body are contained in much smaller quantities, from 0.0001 to 0.01%. These include: iron, manganese, copper, zinc, molybdenum, boron, nickel, silicon, cobalt, selenium, chlorine, etc. As a rule, these are metals of the transition group of the periodic system of elements.
Microelements do not affect the osmotic pressure of the cell, do not participate in the formation of protoplasm, their role is primarily associated with the activity of enzymes. All key metabolic processes, such as reactions of protein and carbohydrate synthesis, decomposition and metabolism of organic substances, fixation and assimilation of some major nutrients (for example, nitrogen and sulfur) occur with the participation of enzymes, which ensure their occurrence at normal temperatures.
With the help of redox processes, enzymes have a regulating effect on plant respiration, maintaining it at an optimal level under unfavorable conditions.
Under the influence of microelements, plant resistance to fungal and bacterial diseases and such unfavorable environmental conditions as lack of moisture in the soil, low or high temperatures, and difficult wintering conditions increases.
It is assumed that the synthesis of plant enzymes itself occurs with the participation of microelements.
Research into determining the role of various microelements in plant metabolism began in the mid-19th century. Detailed study began in the 30s of the 20th century. The function of some of the trace elements is still unclear and research in this area continues.
Iron(Fe) is found in chloroplasts and is a necessary element for many enzymes. Participates in the most important biochemical processes: photosynthesis and chlorophyll synthesis, nitrogen and sulfur metabolism, cell respiration, growth and division.
Iron deficiency in plants is often detected when there is an excess of calcium in the soil, which happens on carbonate or acidic soils after liming. With iron deficiency, interveinal chlorosis of young leaves develops. With increasing iron deficiency, the veins may also become lighter, and the leaf will turn pale completely.
Manganese(Mn) predominates in the metabolism of organic acids and nitrogen. It is part of the enzymes responsible for plant respiration and participates in the synthesis of other enzymes. Activates enzymes responsible for oxidation, reduction and hydrolysis. Directly affects the transformation of light in the chloroplast. Plays an important role in the mechanism of action of indolylacetic acid on cell growth. Participates in the synthesis of vitamin C.
Signs of manganese deficiency appear on young leaves. Chlorosis appears first at the base of the leaf, rather than at its ends (which resembles potassium deficiency). Then, with an increasing deficiency of manganese, interveinal chlorosis appears and, after the chlorotic tissue dies, the leaf becomes covered with spots of different shapes and colors. Leaf turgor may be weakened.
Manganese deficiency increases at low temperatures and high soil moisture.
Copper(Cu) is involved in the metabolism of proteins and carbohydrates, activates some enzymes, participates in photosynthesis, and is important in nitrogen metabolism. Increases plant resistance to fungal and bacterial diseases, protects chlorophyll from decay. For plant life, copper cannot be replaced by another element.
With a lack of copper, white spots appear on the tips of young leaves, they lose turgor, and the ovaries and flowers fall off. The plant has a dwarf appearance.
Zinc(Zn) is involved in the formation of tryptophan, a precursor of auxin (growth hormone), and in protein synthesis. Essential for the conversion and consumption of starch and nitrogen. Increases the plant's resistance to fungal diseases, and with sudden changes in temperature, increases the plant's heat and frost resistance.
With a lack of zinc in plants, the synthesis of vitamins B1 and B6 is disrupted. Zinc deficiency appears more often on older lower leaves, but as the deficiency increases, younger leaves also turn yellow. They become spotted, then the tissue of these areas collapses and dies. Young leaves may be small, their edges curl upward.
Zinc fertilizers increase the drought, heat and cold resistance of plants.
Molybdenum(Mo) is part of the enzyme that converts nitrates into nitrites. Necessary for the plant to fix nitrogen. Under its influence, the content of carbohydrates, carotene and ascorbic acid in plants increases. The chlorophyll content and photosynthetic activity increase.
With a lack of molybdenum, the plant's nitrogen metabolism is disrupted, and mottling appears on old and then middle-aged leaves. Areas of such chlorotic tissue then swell and the edges curl upward. Necrosis develops at the tops of leaves and along their edges.
Bor(B) participates in the synthesis of RNA and DNA, in the formation of hormones. Necessary for the normal functioning of the plant’s growth points, i.e. its youngest parts. It affects the synthesis of vitamins, flowering and fruiting, and seed ripening. Strengthens the outflow of photosynthesis products from leaves into bulbs and tubers. Necessary for water supply to the plant. Boron is necessary for plants throughout the growing season. For plant life, boron cannot be replaced by another element.
With a lack of boron in plants, the growth point is affected, both apical buds and young roots die, and the vascular system is destroyed. Young leaves turn pale and become curly. Side shoots develop vigorously, but they are very brittle and the flowers fall off.
Chlorine(Cl) is an activator of enzymes that release oxygen from water during photosynthesis. Cell turgor regulator, promotes drought resistance of plants.
Plants more often show signs of not a deficiency, but an excess of chlorine, expressed in the premature drying of leaves.
Some macro- and microelements can interact, resulting in changes in their availability to the plant. Here are some examples of such influence:
Zinc-phosphorus, high levels of available phosphorus provoke zinc deficiency.
Zinc-nitrogen, high nitrogen levels provoke zinc deficiency.
Iron-phosphorus, excess phosphorus leads to the formation of insoluble iron phosphate, i.e. inaccessibility of iron to the plant.
Copper-phosphorus, excess phosphorus leads to the formation of insoluble copper phosphate, that is, copper deficiency.
Molybdenum-sulfur, the absorption of molybdenum by plants decreases with an excess of sulfur.
Zinc-magnesium When using magnesium carbonate, the soil pH increases and insoluble zinc compounds form.
Iron-manganese, excess manganese prevents the movement of iron from the roots of the plant upward, leading to glandular chlorosis.
Iron-molybdenum, in low concentrations, molybdenum promotes the absorption of iron. At high concentrations, it interacts with it, forming insoluble iron molybdate, which leads to iron deficiency.
Copper-nitrogen, the application of large doses of nitrogen fertilizers increases the need of plants for copper and intensifies the symptoms of copper deficiency.
Copper-iron, Excess copper provokes iron deficiency, especially in citrus fruits.
Copper-molybdenum, excess copper interferes with the absorption of molybdenum and increases the level of nitrates in the plant.
Copper-zinc, excess zinc leads to copper deficiency. The mechanism of this influence is currently not studied.
Boron-calcium, there is evidence that with a lack of boron, plants cannot normally use calcium, which may be present in sufficient quantities in the soil.
Boron-potassium, The amount of boron absorption and accumulation by plants increases with the increase in potassium in the soil.
Currently, work is underway to study the role in plant physiology of such elements as arsenic(As), mercury(Hg), fluorine(F), iodine(I), etc. These elements were found in plants in even more insignificant quantities. For example, in some antibiotics produced by plants.
The deficiency of elements is directly related to the properties of the soil: on very acidic or alkaline soils, plants tend to be deficient in microelements. This is also caused by an excess of phosphates, nitrogen, calcium carbonate, iron and manganese oxides.
A lack of microelements in the soil does not necessarily lead to the death of the plant, but it causes a decrease in the speed and consistency of the processes responsible for the development of the organism.
Symptoms of deficiency of a particular element can be very characteristic and most often manifest themselves in chlorosis. Although objectively, to identify a deficiency of some element, an analysis of soils and plant tissues is required.
Diagnosis of insufficiency of individual elements in appearance, the plant presents difficulties for a non-specialist:
A change in the appearance of the plant, similar to a lack of elements, can be caused by damage by pests, diseases or unfavorable factors: temperature, flooding or dryness of the earthen clod, as well as insufficient atmospheric humidity;
External signs of mineral starvation caused by a deficiency of a specific element may differ slightly in different plants (for example, symptoms of sulfur deficiency in grapes and legumes). And specifically for the Khoi, this issue has not been studied at all;
In the case of a deficiency of several nutrients, external signs overlap; the plant first compensates for the deficiency of the element that is most lacking. Signs of a deficiency of another element remain; externally, chlorosis of the plant continues;
To determine which element the plant lacks, dynamics in changes in external characteristics are necessary, and this varies with the lack of different elements. Amateurs pay little attention to changes in the nature of manifestations, which makes diagnosis difficult;
Nutrients are present in the soil, but are not available to the plant due to its inappropriate acidity.
In order to determine by external signs which specific nutritional element the plant is lacking, you should first pay attention to which leaves, young or old, show symptoms of deficiency.
If they appear on old leaves, a lack of nitrogen, phosphorus, potassium, zinc or magnesium can be assumed. When these elements are deficient in the plant, they move from old parts to young, growing ones. And there are no signs of starvation in them, while chlorosis appears on the lower leaves.
If deficiency symptoms occur in growing points or on young leaves, one can assume a lack of calcium, boron, sulfur, iron, copper and manganese. Apparently, these elements are not able to move throughout the plant from one part to another. And if there are few of these elements in the soil, the growing parts do not receive them.
Therefore, amateurs in a situation where their plants begin to develop chlorosis, but they are sure that the plant is healthy and is in favorable conditions, should treat their plant with a whole complex of macro- or microelements. When choosing preparations, you should understand that the effectiveness of a microelement on a plant directly depends on the form in which it exists. And the insufficient supply of microelements to the plant is often associated with their presence in the soil in an insoluble form, inaccessible to the plant.
About what types of microfertilizers the market offers.
First of all, there are many microfertilizers on the market, which are soluble mineral(inorganic) salts of these elements (magnesium sulfate, zinc sulfate, etc.). Their use is relatively inexpensive, but has a number of serious disadvantages:
These salts are soluble, that is, available to plants, only in soils with slightly acidic and acidic soils;
When using soluble salts of microelements, the soil becomes salinized with various cations and anions (Na, Cl);
When mixing various metal salts, it is possible for them to interact with the formation of insoluble salts, that is, compounds inaccessible to plants.
Therefore, it is more promising to use sodium and potassium salts of humic acids. They are weak natural chelates and are highly soluble.
Humic preparations Gumat+7, Humisol, GrowAP Energy, Lignohumate, Viva and others contain 60-65% humates (in dry form) and seven basic microelements (Fe, Cu, Zn, Mn, Mo, Co, B) in the form of complex compounds with humic acids. They may contain macronutrients and vitamins. These fertilizers are obtained by treating peat or brown coal with an alkali solution at high temperature and extracting the main product from it. At their core, these fertilizers are organic; they do not contain more microelements than manure, and they cannot be considered a full-fledged microelement supplement.
Most noteworthy trace elements in chelated form (chelates). And before we talk about the specific names of microfertilizers in this form, we should dwell on what chelates are. They are obtained by the interaction of metals (microelements) with natural or synthetic organic acids of a certain structure (they are called complexones, chelants or chelating agents). The resulting stable compounds are called chelates (from the Greek “chele” - claw) or complexonates.
When interacting with a metal, an organic molecule, as it were, captures the metal in a “claw,” and the plant cell membrane recognizes this complex as a substance related to its biological structures, and then the metal ion is absorbed by the plant, and the complexon breaks down into simpler substances.
The main idea of using complexons to improve the solubility of fertilizer salts is based on the fact that many metal chelates have greater solubility (sometimes by an order of magnitude) than salts of inorganic acids. Considering also that in the chelate the metal is in a semi-organic form, which is characterized by high biological activity in the tissues of the plant body, it is possible to obtain a fertilizer that is much better absorbed by the plant.
The acids most commonly used in the production of chelated microfertilizers can be divided into two groups. These are complexons containing carboxyl groups:
- EDTA (ethylenediaminetetraacetic acid), synonym: complexone-III, trilon-B, chelaton III.
- DTPA (diethylenetriamine pentaacetic acid)
- DBTA (dihacid)
- EDDNMA (ethylenediaminedi(2-hydroxy-4-methylphenyl) acetic acid)
- LPCA (lignin polycarboxylic acid)
- NTA (nitrilotriacetic acid)
- EDDA (ethylenediaminedisuccinic acid)
and complexones based phosphonic acids:
- HEDP (oxyethylidene diphosphonic acid)
- NTP (nitrilotrimethylenephosphonic acid)
- EDTP (ethylenediaminetetraphosphonic acid)
Of the complexones containing carboxyl groups, the most optimal is DTPA, it allows the use of complexonates (especially iron) on carbonate soils and at pH above 8, where other acids are ineffective.
In our market, as well as abroad (Holland, Finland, Israel, Germany), the vast majority of drugs are based on EDTA. This is due, first of all, to its availability and relatively low cost. Chelates based on it can be used on soils with a pH less than 8 (the iron complex with EDTA is effective in combating chlorosis only on moderately acidic soils; it is unstable in an alkaline environment). In addition, chelates with EDTA are decomposed by soil microorganisms, which leads to the transition of trace elements into an insoluble form. These drugs exhibit antiviral activity.
Chelates based EDDNMA are highly effective and can be used in pH ranges from 3.5 to 11.0. However, the cost of this complexon, and therefore microfertilizer, is high.
Of the complexones containing phosphonic groups, the most promising is OEDF. On its basis, all individual metal complexonates used in agriculture, as well as compositions of various compositions and ratios, can be obtained. In its structure, it is closest to natural compounds based on polyphosphates (during its decomposition, chemical compounds are formed that are easily absorbed by plants). Chelates based on it can be used on soils with pH 4.5-11. A distinctive feature of this complexon is that, unlike EDTA, it can form stable complexes with molybdenum and tungsten. However, HEDP is a very weak complexing agent for iron, copper and zinc; in the root zone they are replaced by calcium and precipitate. For the same reason, it is unacceptable to prepare working solutions of chelates based on HEDP in hard water (it must be acidified with a few drops of citric or acetic acid). HEDF is resistant to soil microorganisms.
Research into chelating properties is currently underway. humus(humic and fulvic acids) as well as amino acids and short peptides.
It is impossible to give an unambiguous answer to the question of which complexone should be used to obtain biologically active microelements: complexones themselves are practically inert for plants. The main role belongs to the metal cation, and the complexon plays the role of a vehicle that ensures the delivery of the cation and its stability in the soil and nutrient solutions. But it is the complexons that ultimately determine the effectiveness of the fertilizer as a whole, that is, the degree of absorption of microelements by plants. If we compare the absorption of microelements by plants from inorganic salts and their chelate compounds, then compounds based on lignins (for example, Brexil from Valagro) are absorbed 4 times better, those based on citrates - 6 times, and those based on EDTA, HEDP, DTPA - 8 times better.
According to the European Union Directive 2003/2003 of October 13, 2003. (this is a document regulating the activities of all European producers of mineral fertilizers without exception), the following chelating agents are allowed for free trade in EU countries: EDTA, DTPA, EDDHA, HEEDTA, EDDHMA, EDDCHA, EDDHSA. All other types of chelating agents are subject to mandatory registration with the relevant government authorities separately in each country.
According to the Directive, the stability constant of microelement chelates, expressed in %, must be at least 80. In the chemistry of complex compounds, the stability constant characterizes the strength of the complex compound and indicates the ratio of the chelated microelement to its free cation in the fertilizer. In advertising materials, the term “chelation percentage”, unknown to chemists, appeared.
You should be wary of advertising information. You should not base your knowledge about the product solely on advertising brochures - the fertilizer manufacturer is not responsible for the information described in the advertising. The main and most reliable information about a product is its LABEL. The fertilizer manufacturer is required to indicate on the label which chelating agent was used to chelate a particular microelement.
The manufacturer, especially the domestic one, however, does not always indicate on the packaging the name of the complexon that he used to produce the microfertilizer. But by strictly following the instructions, the fertilizer can be used as efficiently as possible: if it is indicated that foliar treatment is preferable, you need to follow this, apparently these chelates strongly depend on the acidity of the soil or are destroyed by soil microflora. If watering the plants is also possible, then the chelates are resistant to the listed factors.
Methods of using microfertilizers may be different:
Pre-sowing seed treatment (by pollination or moistening);
Foliar feeding during the growing season (the so-called foliar or leaf method);
Watering with working solutions of microfertilizers.
The first two methods are the most rational and cost-effective. In these cases, plants use 40-100% of all microelements, but when they are added to the soil, the plants absorb only a few percent, and in some cases even tenths of a percent of the microelement added to the soil.
According to the physical state of microfertilizers can be:
Liquid, these are solutions or suspensions with a metal content of 2-6%;
Solid, these are crystalline or powdery substances with a metal content of 6-15%.
The composition of microfertilizers is:
1. NPK fertilizers + microelements in chelated form, which contain various combinations of macroelements N, P, K (Mg, Ca, S are also possible) and a fixed amount of microelements throughout the entire product range.
2. Preparations containing only trace elements, which in turn are also divided into:
- complex - containing a composition of microelements in a certain proportion;
- monofertilizers (chelates of monoelements) - compounds of individual metals: iron, zinc, copper. As a rule, they are used when symptoms of diseases associated with a deficiency of a specific element appear.
3. Fertilizers containing, in addition to microelements, biologically active substances: stimulants, enzymes, amino acids, etc.
From NPK fertilizers + microelements There are several drugs on sale from the company NNPP Nest M (Russia): Tsitovit(N, P, K, Mg, S, Fe, Mn, B, Zn, Cu, Mn, Co) and Siliplant(Si, K, Fe, Mg, Cu, Zn, Mn, Mo, Co, B). It should be noted that this is the first domestic microfertilizer that contains silicon (potassium is present in the preparation for more efficient absorption). It is available in several types with different ratios of microelements.
Buysky chemical plant (Russia) produces the drug Aquarin (№5, №13, №15).
The company VALAGRO (Italy) offers fertilizers Master(16 titles, of which the most interesting are “18+18+18+3”, “13+40+13”, “15+5+30+2”, “3+11+38+4”), Plantafol(in the same proportion of microelements + NPK variations) and Brexil Mix.
I would like to note that these fertilizers should be considered more as correctors of mineral nutrition, and not as a source of microelements.
From preparations containing only microelements, NNPP "Nest M" (Russia) offers Ferovit(chelated iron content not less than 75 g/l, N-40 g/l).
Reakom company (Ukraine) offers microfertilizer Reacom-Mikom(complexon is HEDP) with different ratios of basic microelements (Fe, Mn, Zn, Cu, Co, Mo) and B, designed to meet the needs of a wide variety of crops: tomatoes, cucumbers, grapes, flower crops.
The VALAGRO company also produces microfertilizers in the form of one-component formulas, such as Brexyl Zn, Brexyl Fe, Brexil Mg , Brexil Mn , Brexil Ca(the chelates of these fertilizers are made on the basis of the complexon LPKK).
To microfertilizers with the addition of biostimulants refers to a drug from the company Reakom (Ukraine) under the brand name Reastim, which is a complex of microfertilizers with known growth stimulants (hetero- and hyperoauxins, succinic acid, gibberillin, humic acids, etc.).
Nanomix LLC (Ukraine) produces liquid microfertilizer Nanomix, containing chelates of Fe, Mn, Zn, Cu, Co, Mg, Ca, Mo, (plus B and S) with the addition of natural biostimulants-adaptogens based on polycarboxylic acids. HEDP and EDDA were used as complexons (which allows the fertilizer to be used on acidic, neutral and slightly alkaline soils). The seed treatment also includes a root growth stimulator - heteroauxin.
Plant nutrition depends both on external factors (light, heat, soil composition) and on what phase of development the plant is in (in the growth phase, flowering, dormant state). Therefore, when purchasing fertilizers, you should pay attention to the ratio of nutrients in it. So the plant needs an increased nitrogen content in the spring, in the active growth phase. In summer, for flowering and fruiting, the fertilizer must contain more phosphorus. In the fall, for young shoots to ripen, the fertilizer should contain no nitrogen at all, and potassium should be present in high concentrations. In winter, indoor plants are fertilized extremely rarely (and in low concentrations), because in a dormant state the plant does not consume many nutrients. Their application can burn the roots or, in conditions of elevated temperatures and short daylight hours, will provoke growth that will be weakened.
Indoor plants live in unnatural conditions: the volume of soil is limited by the pot, and therefore the amount of nutrients is limited.
When you transplant a flower into new soil, you give it enough nutrients (modern soils sold in stores usually have a fairly balanced composition, which allows you to do without fertilizing for about 2 months), but as it grows, the amount of nutrients in the soil decreases and the plant begins to grow. starve in the truest sense of the word. A weakened plant is easy prey for pests and diseases.
Then feeding comes to the rescue.
Feeding plants almost always improves their condition. A lack of nutrients in the soil can be detected by external signs: the leaves have begun to turn yellow, turn white, the plant has slowed down, etc.
Macronutrients for plants - breakfast, lunch and dinner
These are substances that plants need in large quantities, their concentration is 0.1-10%.
Macroelements include nitrogen, potassium, phosphorus, sulfur, calcium, magnesium. needed for the growth of shoots and leaves. If the soil lacks nitrogen, the color of the plants changes: from rich green it becomes pale, yellowish. The leaves turn yellow, become smaller and fall off, the plant sheds its buds. This is called chlorosis - not a disease, but a weakening of the plant.
Excess nitrogen leads to vigorous growth of the plant. But this is not good, because the tissues become loose, as if thrown together in a hurry, flowering is delayed and the plant becomes susceptible to diseases. Regular liquid fertilizer almost always contains nitrogen. Look at the composition of the fertilizer and you will see the Latin letter N there. This is nitrogen. Nitrogen fertilizers are most needed at the beginning of plant growth - in the spring. By autumn, its consumption decreases, and in winter, nitrogen must be completely excluded from fertilizing.
Nitric and nitrous acid salts, ammonium, and carbamide (urea) can serve as a source of nitrogen for plant nutrition. provides tissue strength and plant immunity. If there is not enough potassium, the edges of the leaves curl downwards, become wrinkled, turn yellow or brown and die. A severe lack of potassium leads to the death of old leaves, while young leaves are preserved. Plants especially need potassium during flowering and fruiting.
Potash mineral fertilizers include potassium chloride and potassium sulfate. necessary for plant health, the formation of flowers, fruits and seeds, and forms adventitious roots in cuttings. If there is little phosphorus, the growth and development of plants is delayed, they bloom late or do not bloom at all. With a lack of phosphorus, the leaves become dark green or bluish in color, red-violet spots appear on them, and drying leaves have an almost black color. Excess phosphorus causes the plant to become smaller, the lower leaves wrinkle, turn yellow and fall off. Phosphorus is especially necessary during the period of budding and flowering.
Special sulfur fertilizers are usually not applied, since it is contained in superphosphate, potassium sulfate, and manure. regulates water balance. A lack of calcium primarily affects young shoots and leaves: they turn pale and curl, and brown spots appear on them. However, excess calcium is much more harmful than its deficiency: it makes iron compounds unavailable to the plant, causing chlorosis.
If you notice white-brown stripes on the surface of the soil, try to change the soil completely by replanting the plant in new soil. If the plant is too large, change the top layer of soil. Otherwise, the plant may die. The quality of water for irrigation also matters: hard water contains a lot of calcium, which, unlike other elements, is introduced into the soil with each watering. Use soft water for watering.
Magnesium promotes the absorption of phosphorus by plants. A lack of magnesium leads to chlorosis: the leaves turn yellow, red, purple between the veins and along the edge of the leaf. The leaves curl, the root system develops poorly, which leads to depletion of the plants.
Iron participates in the formation of chlorophyll and respiration. If a plant lacks iron, the leaves turn pale green but do not die. A lack of iron leads to complete chlorosis: the entire surface of first young and then all other leaves turns pale and discolored. White leaves appear.
If there is a shortage sulfur plants are stunted, leaves turn pale.
Microelements for plants are vitamins
Plants need microelements in very small doses, their concentration is less than 0.01%.
The tips of the leaves turn white - the plant lacks copper.
The apical buds and roots die off, the plant does not bloom, the leaves turn brown and die - there is little in the soil boron.
The plant does not grow, and the leaves have become variegated - this is a drawback manganese
If there is a shortage cobalt The root system of plants develops poorly.
Light areas appeared between the veins of the leaves, the tips turned yellow, the leaves began to die - the plant didn’t have enough zinc
Flaw molybdenum leads to disruption of nitrogen metabolism, causes yellowing and spotting of leaves, and death of the growing point.
Sodium and chlorine necessary for plants from sea coasts and salt marshes. However, in cultivation these plants usually do not have increased requirements for soil salinity.
Any plant is a real living organism, and in order for its development to proceed fully, vital conditions are required: light, air, moisture and nutrition.
All of them are equivalent and the lack of one has a detrimental effect on the overall condition. In this article we will talk about such an important component in the life of plants as mineral nutrition.
Features of the nutrition process
Being the main source of energy, without which all life processes die out, food is necessary for every body. Consequently, nutrition is not just important, but one of the main conditions for the high-quality growth of a plant, and they obtain food by using all above-ground parts and the root system. Through their roots, they extract water and the necessary mineral salts from the soil, replenishing the necessary supply of substances, providing soil or mineral nutrition to plants.
A significant role in this process is assigned to root hairs, so this type of nutrition has another name - root. With the help of these thread-like hairs, the plant draws aqueous solutions of a wide variety of chemical elements from the ground.
They work on the principle of a pump and are located on the root in the suction zone. Salt solutions entering the hair tissue move into conducting cells - tracheids and vessels. Through them, substances enter the wires and then spread along the stems to all above-ground parts.
Elements of mineral nutrition for plants
So, food for representatives of the plant kingdom are substances obtained from the soil. Mineral or soil nutrition of plants is the unity of different processes: from absorption and promotion to the assimilation of elements found in the soil in the form of mineral salts.
Studies of ash left over from plants have shown how many chemical elements remain in it and their quantity in different parts and different representatives of the flora is not the same. This is evidence that chemical elements are absorbed and accumulated in plants. Such experiments led to the following conclusions: the elements found in all plants are considered vital - phosphorus, calcium, potassium, sulfur, iron, magnesium, as well as microelements represented by zinc, copper, boron, manganese, etc.
Despite the different amounts of these substances, they are present in any plant, and replacing one element with another is impossible under any circumstances. The level of presence of minerals in the soil is very important, since the productivity of agricultural crops and the decorativeness of flowering plants depend on it. In different soils, the degree of saturation of the soil with the necessary substances is also different. For example, in the temperate latitudes of Russia there is a significant shortage of nitrogen and phosphorus, and sometimes potassium, so the application of fertilizers - nitrogen and potassium-phosphorus - is mandatory. Each element has its own role in the life of the plant organism.
Proper plant nutrition (mineral) stimulates quality development, which occurs only when all the necessary substances are present in the required quantities in the soil. If there is a shortage or excess of some of them, plants react by changing the color of the foliage. Therefore, one of the important conditions for agricultural technology of agricultural crops is the developed standards for applying fertilizing and fertilizers. Note that it is better to underfeed many plants than to overfeed them. For example, for all berry garden crops and their wild forms, it is excess nutrition that is destructive. Let's find out how different substances interact with and what each of them affects.
Nitrogen
One of the most essential elements for plant growth is nitrogen. It is present in proteins and amino acids. Nitrogen deficiency manifests itself in changes in leaf color: at first, the leaf becomes smaller and turns red. A significant deficiency causes an unhealthy yellow-green color or bronze-red coating. The older leaves on the bottom of the shoots are affected first, then along the entire stem. With continued deficiency, branch growth and fruit set stop.
Excessive compounds lead to increased nitrogen content in the soil. At the same time, rapid growth of shoots and intensive growth of green mass are observed, which does not allow the plant to lay flower buds. As a result, the productivity of the plant is noticeably reduced. This is why balanced mineral soil nutrition of plants is so important.
Phosphorus
This element is no less important in plant life. It is a constituent part of nucleic acids, the combination of which with proteins forms nucleoproteins that are part of the cell nucleus. Phosphorus is concentrated in plant tissues, flowers and seeds. In many ways, the ability of trees to withstand natural disasters depends on the availability of phosphorus. It is responsible for frost resistance and comfortable wintering. Deficiency of the element manifests itself in a slowdown in cell division, cessation of plant growth and development of the root system, the foliage acquires a purple-red hue. Worsening the situation threatens the plant with death.
Potassium
Plant nutritional minerals include potassium. It is needed in the greatest quantities, since it stimulates the process of absorption, biosynthesis and transportation of vital elements to all parts of the plant.
Normal supply of potassium increases the resistance of the plant organism, stimulates defense mechanisms, drought and cold resistance. Flowering and fruit formation with sufficient potassium supply are more efficient: flowers and fruits are much larger and brighter in color.
If there is a deficiency of the element, growth slows down significantly, and severe deficiency leads to thinning and fragility of the stems, and a change in the color of the leaves to lilac-bronze. The leaves then dry out and collapse.
Calcium
Normal soil nutrition of plants (mineral) is impossible without calcium, which is present in almost all cells of the plant body, stabilizing their functionality. This element is especially significant for the quality growth and functioning of the root system. Calcium deficiency is accompanied by delayed root growth and ineffective formation of the root system. A lack of calcium manifests itself in the redness of the edges of the upper leaves on young shoots. Increasing deficiency will add purple coloration throughout the entire leaf area. If calcium never reaches the plant, then the leaves of the current year’s shoots dry out along with the tops.
Magnesium
The process of mineral nutrition of plants during normal development is impossible without magnesium. Being part of chlorophyll, it is an essential element of the photosynthesis process.
By activating enzymes involved in metabolism, magnesium stimulates the formation of growth buds, seed germination and other reproductive activities.
Signs of magnesium deficiency are the appearance of a reddish tint at the base of the leaves, spreading along the central conductor and occupying up to two-thirds of the leaf blade. Severe magnesium deficiency leads to leaf necrosis, reduced plant productivity and its decorative properties.
Iron
Responsible for the normal respiration of plants, this element is indispensable in redox processes, since it is it that accepts oxygen molecules and synthesizes chlorophyll precursor substances. When iron deficiency occurs, the plant becomes lighter and thinner, acquiring a yellowish-green and then bright yellow color with dark rusty spots. Impaired breathing provokes a slowdown in plant growth and a significant reduction in yield.
Manganese
Without exaggerating the importance of essential microelements, let us remember how plants and soil react to them. The mineral nutrition of plants is supplemented with manganese, which is essential for the productive course of photosynthesis processes, as well as protein synthesis, etc. A lack of manganese manifests itself in weak young growth, and a severe deficiency makes it unviable - the leaves on the stems turn yellow, the tops of the shoots dry out.
Zinc
This microelement is an active participant in the process of auxin formation and a catalyst for plant growth. Being an essential component of chloroplasts, zinc is present during the photochemical breakdown of water.
It is necessary for fertilization and development of the egg. Zinc deficiency becomes noticeable at the end and during rest - the leaves take on a lemon tint.
Copper
Mineral or root nutrition of plants will be incomplete without this microelement. Part of a number of enzymes, copper activates such important processes as plant respiration, protein and carbohydrate metabolism. Copper derivatives are essential components of photosynthesis. The deficiency of this element is manifested by drying of the apical shoots.
Bor
Stimulating the synthesis of amino acids, carbohydrates and proteins, boron is present in many enzymes that regulate metabolism. A sign of acute boron deficiency is the appearance of variegated spots on young stems and a bluish tint to the leaves at the base of the shoots. Further deficiency of the element leads to the destruction of foliage and the death of young growth. Flowering is weak and unproductive - fruits are not set.
We have listed the main chemical elements necessary for normal development, high-quality flowering and fruiting. All of them, properly balanced, constitute high-quality mineral nutrition for plants. And the importance of water is also difficult to overestimate, because all substances from the soil come in dissolved form.
Just like people and animals, plants vitally need nutrients, which they receive from soil, water and air. The composition of the soil directly affects the health of the plant, because the soil contains the main microelements: iron, potassium, calcium, phosphorus, manganese and many others. If any element is missing, the plant gets sick and may even die. However, an excess of minerals is no less dangerous.
How do you know which element in the soil is not enough or, conversely, too much? Soil analysis is carried out by special research laboratories, and all large crop-growing farms resort to their services. But what should ordinary gardeners and home flower lovers do, how can they independently diagnose a lack of nutrients? It's simple: if the soil lacks iron, phosphorus, magnesium and any other substance, the plant itself will tell you about it, because the health and appearance of a green pet depends, among other things, on the amount of mineral elements in the soil. In the table below you can see a summary of the symptoms and causes of the disease.
Let's take a closer look at the symptoms of deficiency and excess of individual substances.
Micronutrient deficiency
Most often, a plant experiences a deficiency of individual microelements when the soil composition is not balanced. Too high or, conversely, low acidity, excessive content of sand, peat, lime, chernozem - all this leads to a lack of any mineral component. The content of microelements is also influenced by weather conditions, especially extremely low temperatures.
Typically, the symptoms characteristic of micronutrient deficiency are pronounced and do not overlap with each other, so identifying a lack of nutrients is quite simple, especially for an experienced gardener.
[!] Do not confuse external manifestations characteristic of a lack of minerals with manifestations that occur when plants are damaged by viral or fungal diseases, as well as various types of insect pests.
Iron– an element vital for the plant, participating in the process of photosynthesis and accumulated mainly in the leaves.
Lack of iron in the soil, and therefore in the plant’s nutrition, is one of the most common diseases, called chlorosis. And, although chlorosis is a symptom that is also characteristic of a deficiency of magnesium, nitrogen and many other elements, iron deficiency is the first and main cause of chlorosis. Signs of iron chlorosis are yellowing or whitening of the interveinal space of the leaf plate, while the color of the veins themselves does not change. First of all, the upper (young) leaves are affected. The growth and development of the plant does not stop, but the newly emerging shoots have an unhealthy chlorotic color. Iron deficiency most often occurs in soils with high acidity.
Iron deficiency is treated with special preparations containing iron chelate: Ferrovit, Mikom-Reacom Iron Chelate, Micro-Fe. You can also make your own iron chelate by mixing 4 grams. iron sulfate with 1 liter. water and adding 2.5 g to the solution. citric acid. One of the most effective folk methods for eliminating iron deficiency is to stick several old rusty nails into the soil.
[!] How do you know that the iron content in the soil has returned to normal? Young growing leaves have a normal green color.
Magnesium. About 20% of this substance is contained in the chlorophyll of the plant. This means that magnesium is necessary for proper photosynthesis. In addition, the mineral is involved in redox processes
When there is not enough magnesium in the soil, chlorosis also occurs on the leaves of the plant. But, unlike signs of iron chlorosis, the lower, older leaves are affected first. The color of the leaf plate between the veins changes to reddish, yellowish. Spots appear throughout the leaf, indicating tissue death. The veins themselves do not change color, and the overall color of the leaves resembles a herringbone pattern. Often, with a lack of magnesium, you can see leaf deformation: curling and wrinkled edges.
To eliminate the lack of magnesium, special fertilizers are used that contain a large amount of the necessary substance - dolomite flour, potassium magnesium, magnesium sulfate. Wood ash and ashes well compensate for magnesium deficiency.
Copper important for proper protein and carbohydrate processes in the plant cell and, accordingly, plant development.
Excessive content of peat (humus) and sand in the soil mixture often leads to copper deficiency. This disease is popularly called white plague or white-tailed plague. Citrus home plants, tomatoes, and cereals react especially sharply to copper deficiency. The following signs will help identify a lack of copper in the soil: general lethargy of leaves and stems, especially the upper ones, delay and stopping of the growth of new shoots, death of the apical bud, white spots on the tip of the leaf or along the entire leaf blade. In cereals, leaf curling into a spiral is sometimes observed.
To treat copper deficiency, copper-containing fertilizers are used: superphosphate with copper, copper sulfate, pyrite cinders.
Zinc has a great influence on the rate of redox processes, as well as on the synthesis of nitrogen, carbohydrates and starches.
Zinc deficiency usually occurs in acidic swampy or sandy soils. Symptoms of zinc deficiency are usually localized to the leaves of the plant. This is a general yellowing of the leaf or the appearance of individual spots; often the spots become more saturated, bronze in color. Subsequently, the tissue in such areas dies. Symptoms first appear on the old (lower) leaves of the plant, gradually rising higher. In some cases, spots may appear on the stems. Newly emerging leaves are abnormally small in size and covered with yellow specks. Sometimes you can see the leaf curling upward.
In case of zinc deficiency, zinc-containing complex fertilizers or zinc sulfate are used.
Bor. With the help of this element, the plant fights viral and bacterial diseases. In addition, boron is actively involved in the process of growth and development of new shoots, buds, and fruits.
Swampy, carbonate and acidic soils very often lead to boron starvation of the plant. Various types of beets and cabbage especially suffer from boron deficiency. Signs of boron deficiency appear primarily on young shoots and upper leaves of the plant. The color of the leaves changes to light green, the leaf blade curls into a horizontal tube. The leaf veins become dark, even black, and break when bent. The upper shoots suffer especially severely, even to the point of dying, and the growth point is affected, as a result of which the plant develops with the help of lateral shoots. The formation of flowers and ovaries slows down or completely stops, and flowers and fruits that have already appeared fall off.
Boric acid will help compensate for the lack of boron.
[!] Boric acid must be used with extreme caution: even a slight overdose will lead to the death of the plant.
Molybdenum. Molybdenum is necessary for photosynthesis, vitamin synthesis, nitrogen and phosphorus metabolism, in addition, the mineral is a component of many plant enzymes.
If a large number of brown or brown specks appear on the old (lower) leaves of the plant, but the veins remain normal green, the plant may be lacking molybdenum. In this case, the surface of the leaf is deformed, swelling, and the edges of the leaves curl. New young leaves do not change color at first, but over time, mottling appears on them. The manifestation of molybdenum deficiency is called “Whiptail disease”
Molybdenum deficiency can be replenished with fertilizers such as ammonium molybdate and ammonium molybdate.
Manganese necessary for the synthesis of ascorbic acid and sugars. In addition, the element increases the chlorophyll content in the leaves, increases the plant’s resistance to adverse factors, and improves fruiting.
Manganese deficiency is determined by the pronounced chlorotic color of the leaves: the central and lateral veins remain deep green, and the interveinal tissue becomes lighter (becomes light green or yellowish). Unlike iron chlorosis, the pattern is not so noticeable, and the yellowness is not so bright. Symptoms can initially be seen at the base of the upper leaves. Over time, as the leaves age, the chlorotic pattern blurs, and stripes appear on the leaf blade along the central vein.
To treat manganese deficiency, manganese sulfate or complex fertilizers containing manganese are used. From folk remedies, you can use a weak solution of potassium permanganate or diluted manure.
Macroelements include nitrogen, potassium, phosphorus, sulfur, calcium, magnesium.– one of the most important elements for a plant. There are two forms of nitrogen, one of which is necessary for oxidative processes in the plant, and the other for reduction processes. Nitrogen helps maintain the necessary water balance and also stimulates the growth and development of the plant.
Most often, a lack of nitrogen in the soil occurs in early spring, due to low soil temperatures that prevent the formation of minerals. Nitrogen deficiency is most clearly manifested at the stage of early plant development: thin and sluggish shoots, small leaves and inflorescences, low branching. In general, the plant develops poorly. In addition, a lack of nitrogen may be indicated by a change in the color of the leaf, in particular the color of the veins, both central and lateral. With nitrogen starvation, the veins first turn yellow, and subsequently the periveinal tissues of the leaf also turn yellow. Also, the color of the veins and leaves may become reddish, brown or light green. Symptoms appear first on older leaves, eventually affecting the entire plant.
The lack of nitrogen can be compensated for by fertilizers containing nitrate nitrogen (potassium, ammonium, sodium and other nitrates) or ammonium nitrogen (ammophos, ammonium sulfate, urea). High nitrogen content is present in natural organic fertilizers.
[!] In the second half of the year, nitrogen fertilizers should be excluded, as they can prevent the plant from transitioning from a dormant state and preparing for wintering.
Phosphorus. This microelement is especially important during the period of flowering and fruit formation, as it stimulates the development of the plant, including fruiting. Phosphorus is also necessary for proper wintering, so the best time to apply fluoride-containing fertilizers is the second half of summer.
Signs of phosphorus deficiency are difficult to confuse with any other symptoms: leaves and shoots turn bluish, and the glossiness of the leaf surface is lost. In particularly advanced cases, the color may even be violet, purple or bronze. Areas of dead tissue appear on the lower leaves, then the leaf completely dries out and falls off. Fallen leaves are dark, almost black. At the same time, young shoots continue to develop, but look weakened and depressed. In general, a lack of phosphorus affects the overall development of the plant - the formation of inflorescences and fruits slows down, and the yield decreases.
Treatment of phosphorus deficiency is carried out using phosphate fertilizers: phosphate flour, potassium phosphate, superphosphate. A large amount of phosphorus is found in bird droppings. Ready-made phosphorus fertilizers take a long time to dissolve in water, so they must be applied in advance.
Nitric and nitrous acid salts, ammonium, and carbamide (urea) can serve as a source of nitrogen for plant nutrition.- one of the main elements of plant mineral nutrition. Its role is enormous: maintaining water balance, increasing plant immunity, increasing resistance to stress, and much more.
An insufficient amount of potassium leads to leaf edge burn (deformation of the leaf edge accompanied by drying). Brown spots appear on the leaf blade, the veins look as if pressed into the leaf. Symptoms appear first on older leaves. Often, a lack of potassium leads to active leaf fall during the flowering period. The stems and shoots droop, the development of the plant slows down: the appearance of new buds and sprouts and the setting of fruits are stopped. Even if new shoots grow, their shape is underdeveloped and ugly.
Fertilizers such as potassium chloride, potassium magnesia, potassium sulfate, and wood ash help compensate for the lack of potassium.
Special sulfur fertilizers are usually not applied, since it is contained in superphosphate, potassium sulfate, and manure. important for the proper functioning of plant cells, protein and carbohydrate metabolism. The root system is the first to suffer from calcium deficiency.
Signs of calcium deficiency appear primarily on young leaves and shoots: brown spotting, bending, curling. Later, both already formed and newly emerging shoots die. A lack of calcium leads to impaired absorption of other minerals, so the plant may show signs of potassium, nitrogen or magnesium starvation.
[!] It should be noted that house plants rarely suffer from calcium deficiency, since tap water contains quite a lot of salts of this substance.
Lime fertilizers help increase the amount of calcium in the soil: chalk, dolomite limestone, dolomite flour, slaked lime and many others.
Excess of microelements
Too much mineral content in the soil is just as harmful to the plant as its deficiency. Typically, this situation occurs in the case of overfeeding with fertilizers and oversaturation of the soil. Failure to comply with the dosage of fertilizers, violation of the timing and frequency of fertilizing - all this leads to excessive mineral content.
Iron. Excess iron is very rare and usually causes difficulty in absorbing phosphorus and manganese. Therefore, the symptoms of an excess of iron are similar to the symptoms of a deficiency of phosphorus and manganese: a dark, bluish tint of the leaves, cessation of plant growth and development, and the death of young shoots.
Magnesium. If there is too much magnesium in the soil, calcium ceases to be absorbed; therefore, the symptoms of an excess of magnesium are generally similar to the symptoms of calcium deficiency. This is the curling and dying of leaves, a curved and torn shape of the leaf plate, and a delay in the development of the plant.
Copper. When there is an excess of copper, brownish spots appear on the lower, older leaves; subsequently, these areas of the leaf, and then the entire leaf, die. Plant growth slows down significantly.
Zinc. When there is too much zinc in the soil, the plant leaf becomes covered with whitish watery spots on the underside. The leaf surface becomes bumpy, and subsequently the affected leaves fall off.
Bor. Excessive boron content appears primarily on the lower, older leaves in the form of small brownish spots. Over time, the spots increase in size. The affected areas, and then the entire leaf, die.
Molybdenum. If there is an excess of molybdenum in the soil, the plant does not absorb copper well, so the symptoms are similar to those of copper deficiency: general lethargy of the plant, slow development of the growing point, light spots on the leaves.
Manganese. Excess manganese in its symptoms resembles magnesium starvation of a plant: chlorosis on older leaves, spots of different colors on the leaf blade.
Nitrogen. Too much nitrogen leads to rapid growth of green mass to the detriment of flowering and fruiting. In addition, an overdose of nitrogen in combination with excessive watering significantly acidifies the soil, which in turn provokes the formation of root rot.
Phosphorus. Excessive amounts of phosphorus interfere with the absorption of nitrogen, iron and zinc, resulting in symptoms characteristic of a deficiency of these elements.
Potassium. If the soil contains too much potassium, the plant stops absorbing magnesium. The development of the plant slows down, the leaves acquire a pale green color, and a burn occurs along the contour of the leaf.
Plants suffer not only from specific pests and pathogens, but also from disruption of normal living conditions. Non-infectious diseases develop with a lack or excess of certain nutrients, with a lack or excess of moisture, under the influence of mechanical damage, damage from frost, sun, and improper treatment with pesticides.
The cause of a non-infectious disease is abiotic environmental factors that disrupt certain physiological, biochemical functions of plants, causing a pathological process.
Signs of diseases on identical plants appear simultaneously, en masse, throughout the entire field, garden, greenhouse, etc.
Diseases are not transmitted from plant to plant, their development can be stopped by eliminating the effect of an unfavorable factor.
For the normal functioning of a plant organism, only a small group of elements is required. Nutrients are substances necessary for plant life. An element is considered essential if its absence prevents the plant from completing its life cycle; a deficiency of an element causes specific disturbances in the life of the plant, which are prevented or eliminated by the addition of this element; the element directly participates in the processes of transformation of substances and energy, and does not act on the plant indirectly.
It has been established that the elements necessary for higher plants (except for 45% carbon, 6.5% hydrogen, 42% oxygen, assimilated in the process of air nutrition) include the following:
Macronutrients, the content of which ranges from tens to hundredths of a percent: N, P, S, K, Ca, Mg, Fe;
Microelements, the content of which ranges from thousandths to hundred thousandths of a percent: Cu, Mn, Zn, Mo, B.
The need of plants for these elements depends on the biological properties of plants and soil and climatic conditions. The meaning of each of the batteries is strictly specific, so none of them can be replaced by another.
A lack of one or another nutrient can cause serious disturbances in the development of plants, which manifest themselves in the form of characteristic symptoms. Symptoms can be quite clear and specific, but they can also be uncharacteristic. Outwardly, this is expressed not only in a change in the general appearance of the plant (underdevelopment, dwarfism, etc.), but also in the manifestation of symptoms characteristic of this type of starvation - necrosis on the leaves, changes in the color of certain organs, etc.
Starvation of plants is not always caused by the absence or insufficient content of one or another element in the soil. Battery availability depends on their shape, soil conditions (acidity, humidity, buffer properties), the composition of the microflora, which must be taken into account when diagnosing and carrying out protective measures.
External signs of a lack of certain nutrients in different plants are different. Therefore, by external signs one can judge the lack of a particular nutrient in the soil and the need of plants for fertilizers.
Symptoms of plant mineral deficiency can be divided into two large groups:
I. The first group consists mainly of symptoms manifested on old plant leaves. These include symptoms of deficiency of nitrogen, phosphorus, potassium and magnesium. Obviously, if there is a shortage of these elements, they move in the plant from older parts to young growing parts, which do not develop signs of starvation.
II. The second group consists of symptoms manifested on growing points and young leaves. Symptoms of this group characteristic of a lack of calcium, boron, sulfur, iron, copper and manganese. These elements do not appear to be able to move from one part of the plant to another. Consequently, if there is not a sufficient amount of the listed elements in the water and soil, then the young growing parts do not receive the necessary nutrition, as a result of which they get sick and die.
Nitrogen is part of proteins, chlorophyll, alkaloids, phosphatides and other organic compounds. This the most important nutrient for all plants.
Signs of nitrogen deficiency appear very clearly at different stages of development. The general and main signs of nitrogen deficiency in plants are: depressed growth, short and thin shoots and stems, small inflorescences, weak foliage of plants, weak branching and weak tillering, small, narrow leaves, their color is pale green, chlorotic.
***** But change in leaf color may be caused by reasons other than nitrogen deficiency. Yellowing of lower leaves occurs when there is a lack of moisture in the soil, as well as during the natural aging and death of leaves.
With a lack of nitrogen lightening and yellowing of color begins with the veins and the adjacent part of the leaf blade; parts of the leaf removed from the veins may still retain a light green color. On a leaf that has turned yellow from a lack of nitrogen, as a rule, there are no green veins.
*****With natural aging of leaves Their yellowing begins from the part of the leaf blade located between the veins, and the veins and tissues around them still retain a green color.
With a lack of nitrogen Lightening of color begins with older, lower leaves, which acquire yellow, orange and red shades. This coloring extends further to younger leaves and can also appear on leaf petioles. With a lack of nitrogen, leaves fall prematurely, and plant maturation accelerates. Lack of nitrogen reduces the water-holding capacity of plant tissues. Therefore, a low level of nitrogen nutrition not only reduces yield, but also reduces the efficiency of water use by crops. The main source of nitrogen in the soil is humus (humus). The nitrogen content in humus is about 5%.
With a lack of nitrogen in potatoes the color change begins from the tops and edges of the leaf lobes, gradually all the leaves acquire a lighter color than usual; Over time, the color of the leaves may change to pale yellow. In exceptional cases, the edges of the lower leaves lose chlorophyll and curl, sometimes becoming “burned.” Characterized by stunted growth and leaf drop.
Phosphorus includes a composition of nucleic acids, nucleoproteins, phospholipids, enzymes, vitamins. Phosphorus increases the cold resistance of plants, accelerates their development and maturation, improves the development of roots, their deep penetration into the soil, and improves the supply of nutrients and moisture to plants.
Lack of phosphorus in the appearance of plants
more difficult to determine than nitrogen deficiency. With a lack of phosphorus a number of the same symptoms are observed as with a lack of nitrogen - suppressed growth (especially in young plants), short and thin shoots, small, prematurely falling leaves. However, there are significant differences - with a lack of phosphorus The color of the leaves is dark green, bluish, dull. With a severe lack of phosphorus, the color of leaves, leaf petioles and ears appears purple, and in some plants - purple shades. When leaf tissues die, dark, sometimes black spots appear.
Drying leaves have a dark, almost black color, and with a lack of nitrogen - light.
Signs of phosphorus deficiency appear first on older, lower leaves. Characteristic a sign of phosphorus deficiency there is also a delay in flowering and ripening. The main source of phosphorus nutrition is mineral phosphorus compounds in the soil.
With a lack of phosphorus legumes are dark green in color. Petioles and leaf blades are curved upward. The plants are low-growing with thin reddish stems.
Potassium is not found in any organic compound, but forms complexes with them. Nevertheless, the element plays a significant role in plant life. It improves metabolism and increases plant resistance to drought. With sufficient potassium content, a lot of sugars are formed in the leaves, which increases the osmotic pressure of the cell sap and increases the plant’s resistance to light frosts.
Symptoms of Potassium Deficiency begin to appear with the leaves turning pale. Dull bluish-green color of leaves (to chlorotic). The edges of the leaves droop down. A rim of drying tissue appears along the edges of the sheet - an edge “burn”. With severe potassium starvation, browning covers almost the entire leaf blade. Uneven growth of leaf blades, wrinkled leaves. The plant becomes stunted with short internodes, the shoots grow thin.
Signs of potassium starvation can clearly manifest themselves on highly acidic soils and where excessive doses of calcium and magnesium have been added. Potassium deficiency may be accompanied deformation and curling of leaves. Perennials and fruit plants on soils lose their winter hardiness. A slight deficiency of potassium leads to the formation of an unprecedentedly large number of small fruit buds on the trees; the tree is all strewn with flowers, but the fruits from them develop very small.
With a lack of potassium In white cabbage, old leaves turn bronze and then turn brown. Onion leaves at the tips turn yellow and dry out. In carrots, the lower leaves turn pale and curl.
Despite the low content gland in plants, its physiological significance is very great. Iron is part of enzymes involved in respiration and nitrate reduction.
Iron deficiency manifests itself in the form of leaf chlorosis, mainly on perennial plants, in the form of impaired photosynthesis, retarded growth and development. Signs of iron deficiency appear primarily on young leaves. It is most common on carbonate soils, where iron is in a form inaccessible to plants.
Bor concentrated in young leaves and generative organs of plants. It activates the processes of oxidation and photosynthesis.
Boron deficiency
causes suberization. Suberization can be either internal or external. Internal suberization causes dry, hard, brown areas of dead tissue to form in the fruit. Such fruits are much smaller than healthy ones, most of them fall prematurely. External suberization usually develops in the first half of the growing season, before the fruit reaches half its normal size, and most often appears near the calyx. At first, the affected areas have a watery consistency, then they become light brown, wrinkle, and amber-yellow droplets are released on them, which soon harden and fall off. Due to the fact that tissue growth in these areas stops, the fruits are small, deformed, and with cracks. Boron deficiency occurs less frequently on vegetative organs than on the fruits, and is found usually only with a very large deficit.
Plants experience a lack of boron on carbonate soils, as well as when lime is added in high doses.
Beetroot, flax, sunflower, and cauliflower are especially sensitive to the lack of this element.
Manganese is contained in plants in very small quantities, but the growth, development and formation of crop yields of agricultural plants is impossible without it. Manganese takes part in photosynthesis and is part of many ribosomes and chloroplasts, as well as enzymes.
Copper is part of some enzymes and protein molecules. In optimal concentrations, copper promotes the formation and preservation of chlorophyll in leaves.
Copper deficiency It is more often observed on peat bogs, as well as on carbonate and sandy soils. Plants vary in their sensitivity to copper deficiency.
Potatoes are resistant to copper deficiency. Of the grains, wheat is most sensitive to copper deficiency, followed by oats, barley and rye. Lack of copper in cereals causes the so-called processing disease: there is stunting of growth, chlorosis and whitening of the tips of young leaves (in wheat and barley), loss of turgor in young leaves and stems, leaves droop and wither. Plants bushy heavily, stem growth is delayed, seed formation is suppressed (empty grain). In wheat, with a copper deficiency, the leaves covering the ear are slightly chlorotic and twisted, sometimes twisting into a spiral. The head of the ear is also chlorotic and curved, and grain formation is poor. With a severe lack of copper, ears or panicles and seeds do not form.
Calcium found in all plant cells. It enhances metabolism in plants and affects enzyme activity.
Calcium deficiency observed on sandy and sandy loam acidic soils, especially when applying high doses of potassium fertilizers, as well as on solonetzes. Signs of deficiency appear primarily on young leaves. The leaves are chlorotic, twisted, and their edges curl upward. The edges of the leaves are irregular in shape and may show brown scorch. There is damage and death of apical buds and roots, and severe branching of the roots.
Magnesium sandy and sandy loam soddy-podzolic soils are poor.
For magnesium deficiency a characteristic form of chlorosis is observed - at the edges of the leaf and between the veins, the green color changes to yellow, red, violet. Spots of different colors subsequently appear between the veins due to tissue death. At the same time, large veins and adjacent areas of the leaf remain green. The tips of the leaves and edges bend, resulting in leaves arch dome-shaped, the edges of the leaves wrinkle and gradually die. Signs of deficiency appear and spread from the lower leaves to the upper ones.Zinc is part of enzymes and enhances their activity, participates in protein, carbohydrate, and phosphorus metabolism (Shkalikov V. A., 2003).
Zinc deficiency is observed in acidic sandy, carbonate and swamp soils. With a lack of zinc, yellowing and spotting of the leaves are observed, sometimes affecting the leaf veins, bronze shades appear in the color of the leaves, rosette and small leaves; short internodes are formed.
Symptoms of zinc deficiency develop throughout the plant or are localized on older lower leaves. First, on the leaves of the lower and middle tiers, and then on all leaves of the plant, scattered spots of gray-brown and bronze color. The tissue of such areas seems to collapse and then dies. Young leaves are abnormally small and mottled with yellow or uniformly chlorotic, slightly upright, and leaf margins may curl upward. In exceptional cases, the internodes of starved plants are short and the leaves are small and thick. Spots also appear on leaf stems and stems.
Molybdenum is part of enzymes, participates in redox processes, the synthesis of vitamins and chlorophyll, promotes the synthesis and metabolism of protein substances in plants.
Symptoms of molybdenum deficiency appear first on old leaves. Clearly expressed mottling appears; The leaf veins remain light green. Newly developing leaves start out green but become mottled as they grow. Areas of chlorotic tissue subsequently swell, the edges of the leaves curl inward; Necrosis develops along the edges and at the tops of leaves.
The pathological state of plants can also be caused by excess batteries
. An excess of some substances leads to their accumulation in plants and negatively affects the absorption of others. In addition, excessive amounts of mineral salts are often toxic to plants.
Application of nitrogen above the norm, especially in good light, causes strong vegetative growth, in which almost no flower buds are formed. High doses of nitrogen fertilizers require sufficient provision of plants with other elements, in particular copper, boron, magnesium and iron. In early spring and late autumn, when growth is limited by a lack of light, the relative deficiency of elements caused by a large amount of nitrogen is less pronounced. However Violation of the ratio of nitrogen and potassium delays the ripening of shoots. Insufficient watering increases the concentration of water-soluble salts in the soil, which can cause the death of young roots.
Excess nitrogen in the soil leads to lodging of cereals, deterioration in the quality of grains, tubers, root crops, fruits, and reduces resistance to diseases.
In case of excessive application potash fertilizers plants form shortened peduncles; Old leaves quickly turn yellow and the color of flowers deteriorates. If it accumulates in the soil too much potassium, the absorption of magnesium and calcium is difficult. Divalent cations of calcium and magnesium are weakly washed out from protected soil. Their removal by plants is also significantly less than potassium, therefore the average ratio of potassium and magnesium in fertilizing should be 7.5:1. This helps to avoid the negative effects of excess potassium and magnesium deficiency.
Excessive doses of phosphorus cause in soil premature aging of plants. Phosphating negatively affects the availability of iron, zinc and other trace elements.
When systematically watering plants with hard water, calcium accumulates in the soil and the relative deficiency of potassium and magnesium increases. At the same time, the availability of microelements - manganese, boron, iron, zinc - decreases. Excess calcium in plants accelerates the aging process and causes premature leaf loss.
Oversaturation of soils with magnesium increases the deficiency of calcium, potassium and iron.
Sodium increases the concentration of water-soluble salts and also impedes the entry of calcium, magnesium and potassium into plants.
For iron deficiency the supply of plants with manganese, zinc, copper, molybdenum, and sometimes even phosphorus decreases.
Accumulation of copper in roots limits the supply of iron to plants. The copper content in leaves increases slightly when there is an excess in the soil. The toxicity of excess copper usually occurs in soils with low organic matter content. Oversaturation with copper occurs with the systematic use of copper preparations against diseases and pests.
Signs of high zinc levels- watery transparent spots on the lower leaves of plants along the main vein. The leaf blade with irregularly shaped outgrowths becomes uneven; After some time, tissue necrosis occurs and the leaves fall off.
Saturation of soil with boron systematic feeding with freshly diluted slurry, 1 liter of which contains up to 10 mg of boron, contributes. When there is an excess of it, the edges of the lower leaves become brown. Subsequently, brown spots appear between the veins and the leaves fall off.
Harmful excess manganese found on acidic soils, especially when physiologically acidic fertilizers are applied, as well as when there is excess moisture.
Sugar and fodder beets, alfalfa, clover and some other crops are especially sensitive to excess manganese. Excessive intake of manganese is manifested in these crops in characteristic changes on the leaves.
When the first signs of manganese toxicity are detected, it is necessary to add lime, preferably dolomite or marl containing magnesium.
Plants are sensitive to significant changes in ambient temperature conditions . Sharp temperature deviations beyond the limits of the regime suitable for the growth of a given plant cause disturbances in the normal process of its life activity and weaken its protective functions.
Damage to seedlings due to hypothermia is often observed. At temperatures around 0 C, their growth slows down, leaf plates turn yellow and become deformed, and respiratory processes predominate over assimilation processes. The general weakening of the plant organism during prolonged exposure to unfavorable climatic conditions can result in its death. When these conditions improve, slightly damaged plants recover well and can produce a normal harvest. The degree of damage from low temperatures and spring frosts is reduced by following agricultural practices and a good diet, especially potassium.
Freezing is the most harmful to plants., because this process is irreversible and leads to disruption of the integrity of plant tissue. As a result of freezing, ice crystals form in the intercellular spaces and in the cells themselves. When frozen plant tissue thaws, cell sap flows out of it; the fabric first becomes transparent, then turns black and dries out. The richer the plants are in water, the more they are damaged by frost.
In winter for tree species The greatest danger is the alternation of thawing and freezing. After thaws, abruptly giving way to severe frosts, frost cracks and lag of the cortex (flap).
Temperature fluctuations in autumn, winter and especially early spring can cause sun-frost burns.
Burn usually occurs after strong heating of the crust by the sun. This kind of damage is observed on the largest branches and trunks on the south or southwest side.
In the area damaged by sun-frost burn, the bark of the trunk and branches darkens, dries out and falls off, and the exposed wood remains unprotected from adverse effects. Often such burns gradually turn into a cancerous tumor of a non-infectious nature - frost-killing crayfish.
Too high temperature and dry air
in some plants it causes disruption of the stomatal apparatus and increased evaporation; as a result, in many species the seeds are formed weak and underdeveloped.
In cold soil, roots absorb water more slowly, and wilting symptoms can be observed even in conditions of normal humidity. As a result, plants weaken and are more quickly colonized by pathogens that cause root rot.
Excess or lack of moisture also affects normal development: during drought, dwarf growth and premature ripening are observed in herbaceous plants or shedding of leaves in tree species; with excess moisture, cracking of fruits or root tubers occurs.
However soil moisture saturation is not the most important factor. To provide the plant with moisture, it is important how much moisture the roots can take from the soil. And this depends on the type of plant and the nature of the soil.
Due to lack of moisture dwarf growth of herbaceous plants is observed.
To produce plant chlorophyll light needed.
In low light
they become weak and stretched out. The stems of such plants lose strength and often lie down. This happens especially often when crops are planted in dense areas. Lodging is also observed when growing conditions are violated.
With insufficient lighting, plants weaken, their integumentary tissues become thin and are more easily infected by pathogens.
Plants are also negatively affected mechanical damage . This group includes damage to plants caused by various atmospheric phenomena (storm, hail, lightning, downpours, etc.), as well as damage caused by human negligence (breakage of branches, injury to trunks, bruises of fruits, etc.).
Under the influence of strong wind, for example, the leaf blades hit one another, as a result of which shiny, as if polished, blurry spots initially appear on their convex parts. Subsequently, the surface of the leaf in the spots becomes concave and turns brown. Strong winds carrying soil and other solid particles damage leaves, needles, fruits, and shoots, on which numerous small necrotic spots appear. Strong gusts of wind and hurricanes lead to windfall and windfall, especially in plantings affected by rot and cancerous plant diseases. Under the influence of constant strong winds, growth is disrupted, the structure of wood and the shape of trees change.
Damage hail causes the appearance of brown, irregularly shaped spots on the shoots at the impact sites, with torn edges pressed in. On fruits, hailstones appear in the form of depressed, initially brown, then grayish, hard spots with small cracks.
Hail often causes massive loss of flowers, seeds, needles, leaves, damage to tree bark, and death of crops.
Any mechanical damage to the branches, trunks, fruits and other parts of the plant is a “gate” for the penetration of harmful microorganisms, usually found on the surface of the plant organs, in the air, soil, and in fruit collection boxes.
In places of mechanical damage to branches and trunks, for example, infection occurs with black or true (European) cancer, bacterial burn, cytosporosis and other diseases.
Cuts and dents allow fungi and bacteria to penetrate into the internal tissues of the fruit, causing various rots.
Diseases caused by the action of penetrating radiation.
Penetrating radiation is radiation that appears during radioactive decay, which penetrates through the thickness of matter and has a harmful effect on living organisms. These include: X-rays, cosmic rays, γ-rays, α- and β-particles. The effect of penetrating radiation depends on the dose. For most plants, the lethal dose of radiation is about 2000-3000 roentgens. With prolonged exposure to high doses, a pathological process called radiation sickness develops in plants.
The radiation dose received by a plant often depends on the plant’s ability to accumulate radioactive substances in its tissues. The more radionuclides accumulate in a plant, the higher the radiation dose. Therefore, coniferous plants are most sensitive to radioactive contamination, since their evergreen crowns retain a lot of radionuclides falling from the atmosphere with precipitation.
There is a direct relationship between non-communicable and infectious diseases.
Non-communicable diseases create conditions for the spread and development of infectious diseases. Weakened plants quickly become infected with infectious diseases and die.
The fight against non-infectious diseases should be aimed primarily at eliminating the causes that cause them, as well as at creating the most favorable conditions for the growth and development of plants: cultivating resistant varieties, observing crop rotations and optimal planting dates, creating high agricultural backgrounds, and using fertilizers.
Dropsy:
The reason is physiological. Dropsy becomes most noticeable when the air temperature is lower than the soil temperature, soil moisture and relative air humidity are high. The lighting is insufficient.
In indoor conditions, damage can occur if the plants were first kept in excessively dry conditions (dry soil) and then watered abundantly.
Often affected by dropsy ivy-leaved pelargonium due to disturbances in light conditions, insufficient nutrition and high soil moisture.
In addition, Brassica, Dracaena, Fatshedera, Peperomia and Polyscias, begonias, morning glory sweet potatoes, ferns, palms, pansies, cleome, broccoli and cauliflower are prone to dropsy.
May be affected: camellia, eucalyptus, hibiscus, privet, schefflera and yew.
Symptoms:
Dropsy usually appears on the lower surface of the leaves (but can also appear on the upper side of the leaves, on the stem). The first symptom is the appearance of several or multiple watery blisters or "bumps" on the underside of lower or older leaves on the plant. The bubbles soon acquire a dark brown-yellow or rust color; outwardly similar to the fungal disease rust or a manifestation of a bacterial infection. Severely affected leaves often turn yellow and fall off.
In addition, dropsy lesions may resemble spider mite or thrips infestations. To exclude damage by pests, it is necessary to carefully inspect the plants: the undersides of the leaves and growing points.
It is necessary to provide the plant with the necessary level of lighting, do not flood it, and feed it with fertilizers on time.
It is recommended to mulch the soil under outdoor plants.
Ivy-leaved pelargonium Previously, it was recommended to “feed” every third fertilizing with fertilizer with calcium and potassium nitrate; this strengthens the cell walls of plants, making them more resistant to dropsy. However, research at Kansas State University has not shown that supplemental calcium helps prevent dropsy.
Damaged leaves are no longer able to return to their previous appearance, so they can be removed.
The most dropsy-resistant varieties of ivy-leaved pelargonium:
Sugar Baby
Double Lilac White
Salmon Queen
Sybil Holmes
Galilee
Vinco
Van Gogh
Flare
Charade
Lambada
Baroch
Bernardo
Most susceptible:
Amethyst (according to other sources - a moderately resistant variety)
Yale
Balcony Princess
King of Balcony
Balcony Imperial
Balcon Royale
Beauty of Eastborne
Medium resistant:
Madeline Crozy
Cornell
Spain
Pascal
Rigi
Rouletta
Nicole
Blanche Roche
Nico
Pico
