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Mandarin diseases and how to overcome them

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Tangerine tree - Far from being exotic today, and it can be grown even in apartment conditions. How to care, water, and cherish this citrus? This article will provide a complete “instruction for existence” with a tangerine tree.

Care rules

Despite the fact that citruses are still more “southern” plants, they can be grown in greenhouses and apartments in any climate. The main thing is to properly care for the plant, and then the mandarin will delight you not only with its lush flowering, but also with the harvest.

The rules for irrigation mandarin following:

  1. In a period of rapid growth and, as a rule, flowering, the bush needs to be abundant in watering, best of all - daily, but in moderation. This period is from mid-March to the end of September in our climatic conditions.
  2. When the mandarin tree is preparing for the "wintering", watering should be reduced - it will be enough 2 times a week or as the topsoil dries.
  3. "Pour" mandarin can not - roots can rot, and the plant will die. In addition, with abundant watering in winter and late autumn, often begins to "bloom" and mold the soil, which is also not good for citrus.
  4. For irrigation you need to use separated water at room temperature.. During the flowering period (spring), the bush needs additional feeding (in specialized stores you can buy universal means).

Pests and diseases

The main pests of the tangerine tree are spider mites., aphid, scout and thrips. Virtually all pests, if detected and removed in time, will not cause much damage to the plant.

Thrips

For prevention it is necessary to carefully inspect the shrub with each watering, and the leaves - on both sides. If a tree still had a nuisance in the form of pests, it should be washed from them under a warm shower, then spray it with saline solution (approximately 80 g of salt per 1 liter of water).

With spider mites, which appear due to insufficient air humidity, it is necessary to spray the plant more often or to increase the humidity in the room where it grows.

If the above (non-chemical) methods did not help, it is necessary to use specialized means: treatment with actellic or karbofos (about 15 drops per liter of water). As a rule, after such treatment, the pests disappear.

However, it is better to prevent the occurrence of harmful insects than to get rid of them later.

Tangerine diseases include shedding and yellowing of foliage, drying of branches, weakening of the root system. The reasons that the leaves fall off are often insufficient or excessive watering - adjust this process, and the plant should return to the previous state. Drying of the branches and partial death of the root system most often provokes a lack of minerals and fertilizers. Once every 2-3 weeks it is necessary to lure the mandarin in order not to face these troubles.

Popular varieties

The most popular varieties for growing in greenhouse and room conditions are:

  1. Mandarin Unshiu - grows up to 80 cm at home, it has a lush crown, dark green foliage, it blooms beautifully and bears fruit well.
  2. Clementine - A variety that has the sweetest and most delicious fruit. In an apartment, the harvest will not be large, however, bright orange fruits will add color to the house, and a light scent of flowers will bring comfort and ease.
  3. Vasya - the most suitable variety for growing at home. Shrubs do not grow to more than 50 cm. Fruit almost always from the first year. Fruits hang on the branches for a long time, without falling off, and pleasing the eye of their owners. The leaves, in contrast to Unshiu, are bright green, arrow-shaped.

Summarizing, you can give some universal advice to those who wish to grow a beautiful and healthy mandarin tree at home:

  1. Watch for watering, temperature, humidity.
  2. On time, transplant and plant.
  3. Choose the right varieties of fruit for growing in flat conditions.
  4. Cut the tree, remove the pests before they breed.
  5. Love the tangerine bush.

Listening to these simple tips, as a reward you will receive a lush, fresh and eye pleasing plant that will be a worthy decoration of your home.

Wartiness

Another disease caused by the fungus that affects the entire plant. It appears first with small yellow transparent spots on the leaves, which then transform into pinkish-gray warts. The growths that appeared on the young shoots increase and turn into an impressive build-up, which leads to the death of the branch. When the fruit is infected, orange spots grow on them, which, as they grow, acquire brown shades. At the same time the existing ovaries fall. The condition for the spread of the disease is high humidity and air temperature. The fight against the disease is to remove the damaged parts of the plant that it is desirable to burn, so that spores do not spread in the environment. The plant is sprayed with a solution of Bordeaux liquids (1%): in March, in June (after flowering) and in July.

Citrus gommoz

The disease, the causative agent of which is the fungus Pythiacystis citrophthora R.E.Sm, manifests itself in the form of protruding longitudinal drops of gum on the bark of a tree. In general, the infection affects the bark of the trunks and the main roots of the tree, without penetrating into their other layers. Over time, the bark is separated from the rest of the stem or root. If this happens along its circumference, a branch, root, or the whole stem perishes, because the circulation of the sap is disturbed. The fungus can appear on the fruit, causing brown rot.

Before treating a tangerine tree, it is necessary to eliminate the causes that caused the disease.

Among them may be:

  • lack of potassium and phosphorus with an excess of nitrogen in the soil. In this case, the proportion of nitrogen and organic fertilizers decreases.
  • no drainage under the root system of the tree. For a couple of days, watering is completely stopped, and then resumed carefully and with great restriction,
  • too deep planting seedlings,
  • mechanical damage, due to which wounds appeared, where the infection got.

In addition to the measures described above, the following should be carried out. Clean the wound and sanitize it with a solution of blue vitriol (3%). To do this, 30 g of the agent and 200 g of hydrated (or 100 g of quicklime) lime are dissolved in a liter of water. After that, the wound is treated with a garden pitch. The procedure is repeated until the signs of the disease disappear. If this is not achieved, the plant is uprooted and burned.

Late blight

Most often, this fungal disease affects the tangerine trees that were previously grafted on an orange. Often manifested in young seedlings, which are girdled with a brown oily spot. Usually, the damaged area is cleaned and treated with copper sulphate or a similar agent with a higher degree of action. It is recommended to dig up the plant and check whether the roots are damaged by the disease. If the inspection gives a positive result, the tree must be destroyed.

Root rot

It is difficult to find it, because the roots of the plant are affected. The disease usually appears outwardly in an already advanced stage, when the mandarin leaves fall massively. How to reanimate the room tangerine in this case? Dig a plant and inspect the roots. If damaged areas are found, they are removed with a sharp disinfected instrument. All roots are treated with a rooting stimulator, and the plant is transplanted into fresh, clean soil. Then the pot with mandarin should be put in the greenhouse or regularly wipe the leaves with a damp cloth, avoiding abundant watering. Give the plant a good light.

The cause of the disease is the virus of the same name, which affects the entire plant. As a rule, trees over 5 years old become its victims. The first signs are stopping or braking further development and changing the color of the leaves. At first they fade, become slightly bronze, then they acquire a yellowish tint near the veins. At the same time, more mature leaves begin to fall off at the base of the branches. After the leaves fall, branches departing from the trunk weaken and die. Fruits also change color and fall early. If you dig up the plant, it turns out that the root system is affected very much.

The disease is transmitted by insects or by budding (grafting of plants). It is not treated. It is recommended to destroy the infected tree.

Xylopsorosis

A virus that can be in the plant and not develop until 10 years. Outwardly, it is very similar to homosis, as it damages the bark of the plant. But he is not treated.

Infectious disease that affects plants in the open field in the spring, and indoor - from autumn to spring. The first signs of the disease are a dull leaf color. They fall from the tree, while the stalks remain on the branches. After the leaves fall, the shoots begin to dry out with a simultaneous change in the color of the bark. It becomes carrot or orange-red. Drying continues from the end of the branches to the base, and then moves to the main trunk. The disease cannot be cured. The causative agent of the disease Phoma tracheiphila Petri is spread by spores, which in rainy weather appear from the shelter and are carried by the wind or working tools.

Diseases caused by lack of fertilizer and trace elements

Sometimes the external manifestations of plant ailments are signs of a lack of important trace elements in the soil.

So, if old leaves began to be covered with light yellow dots, then turn yellow and dim, most likely the plant lacks nitrogen. If, against the background of tarnishing of the leaf, its tip dries up, acquiring a rusty-brown hue, the mandarin requires additional phosphorus. If between the veins of the leaves began to appear recesses and folds, increase the dose of potassium. About the lack of iron, as well as zinc with manganese, says a grid of green veins on faded leaves. If the ovary began to fall off en masse, the acid-base balance of the soil is likely to be disturbed. It arises due to the deficiencies of manganese and boron. However, an overabundance of all these substances also has a bad effect on the plant. He begins to die off the edges of the leaves.

Mandarintender plant, prone to a variety of diseases. They are mainly caused by various fungi, less often by viruses. They can affect as part of the plant, and completely the whole tree. If in time to detect the first signs of the disease and take appropriate measures, the mandarin can be saved. But there are diseases that can not be cured. In addition, most of them have similar symptoms. And fading, yellowing and falling leaves can only talk about the wrong care of the plant. Therefore, the treatment and care of mandarin must be approached comprehensively.

Causes of Lemon Viral Disease

First of all, it is necessary to understand how the infection of a lemon. This will correct the errors in the content of your tree and prevent re-infection.

Among the causes that lead to diseases, the following can be singled out:
- weak immunity of the plant after previously transferred diseases;
- illiterate content (improper watering, pruning, temperature, lack of light and mineral nutrition),
- poor quality soil
- location next to other diseased plants,
- insects that can carry a variety of viruses,
- summer airing, as a result of which various viruses or fungi can be carried (but the probability of this is very small).

Unfortunately, almost all viral diseases of lemons are incurable. Therefore, if you notice the symptoms of one of them, it is better to get rid of the diseased plant as soon as possible.

Consider the possible viral diseases of citrus.

Psorosis a, or xylopsorosis

Xylopsorosis virus is a dangerous virus that infects the bark of lemon stems. It may be in a latent (that is, at rest) state for about 10 years. Therefore, you can not even guess that your plant is infected with this virus.
In symptomatology, this disease is reminiscent of gommoz, therefore, beginners in citrus fruits rarely manage to identify it in their lemons.

Xylopsorosis on the external sign of manifestation is identical to a simple hommose, but this is very dangerous for the plant.

Xylopsorosis is not treatable, so you have to get rid of the infected lemon.

This disease is caused by the virus of the same name Tristez. An infected tree dies off the bark of the trunk. It affects the whole plant. The most susceptible to this disease are young trees under the age of 5 years.
The virus infects the whole plant. The initial symptoms of this disease are stunting and diminishing fruits.

A leaf is an organ of a plant that performs the functions of photosynthesis, respiration, evaporation and fluids.

Other symptoms of tristeses:
- Whitened leaf veins. Veins seem as if filled with fluid, thick and light. Soon the leaves turn yellow, dry out and fall off.
- The defeat of wood trunks and branches. Longitudinal convex grooves appear on the bark, the contour of the branch cutting becomes uneven. Between the roots and leaves of a tree, the flow of water with dissolved minerals is disturbed, the leaves are undersupplied. The tree is depressed, it languishes and soon dies.

The plant is completely affected by tristeza

But there are varieties of lemons, unresponsive in tristeze. In such plants, the virus may be in a dormant state and does not appear externally. But such resistant plants are carriers of the virus. Therefore, when using cuttings of such plants for vaccination, you can infect another, healthy plant.
Tristeza is not treatable, so the sick Lemon

Lemon is an evergreen plant of the Citrus genus, and this is the name of the fruit of this plant.

Leaf mozayka

This disease is characterized by the appearance of a characteristic pattern on the leaves of the plant. This pattern looks like light streaks or stripes on the leaves. The tree begins to lag behind in growth, its leaves are deformed and fall. The photo sheet mosaic is also the title to this article.

When a leaf mosaic on the leaves of lemon formed characteristic patterns

Sheet mosaic is not as dangerous for other diseases, but like other diseases, it is not amenable to treatment.

Citrus Cancer

Cancer is a dangerous citrus disease. Infection can occur through stomata of leaves or through various plant damage.

His first symptom - spots on the leaves of a dark brown color, similar to small tumors. Each such spot has a yellow area around it, and a depression in the center of the spot.
Symptoms first appear on the leaves and their petioles, then with the course of the disease they also appear on the fruits of the plant.

Lemon fruit has an oval or ovoid, elongated shape, with a small nipple at the tip of the apex. Its length varies from 5 to 10 cm, diameter - from 4 to 7 cm. The color of ripe lemon varies from light yellow to saturated, depending on the variety.

Sick tree withers, sheds the affected leaves. Convex brown areas appear on the bark of the trunk. Shoots die out soon. Spots appear on the fruits of lemon, just like on leaves. Only the peel of the fetus is affected. Most affected lemons do not ripen to the end, but fall off.
There is no cure for cancer.

Lemon viral disease prevention

Since viral diseases do not respond to treatment, there are only ways to prevent their occurrence.
In order to reduce the risk of infection with viral diseases, it is necessary to carry out timely prevention: once a couple of months, process the plant with a solution of potassium permanganate. To do this, prepare a weak solution of potassium permanganate (0.05%), pour the plant with the resulting solution and spray it with a crown of a tree from a spray bottle. It is also worth checking your plants for symptoms of viral diseases from time to time, as they can easily be transmitted to each other.
If you follow these recommendations, diseases will bypass your Lemon.

Lemon is an evergreen plant of the Citrus genus, and this is the name of the fruit of this plant.

Also, the cause of stains on the leaves can be micronutrient deficiencies in the soil, to know what to do, we recommend reading the article: How to determine what a lemon or mandarin is missing from a leaf?

Citrus Diseases and Pests

Citrus pests and diseases cause great damage to the quality and quantity of the crop. Indoor conditions create ideal conditions for their existence and reproduction. Therefore, in greenhouse conditions, the control of pests and diseases of lemon is of paramount importance in order to avoid yield loss.

To prevent the occurrence of pests and diseases in the greenhouse, preventive measures are constantly being taken. From May to August, the greenhouse is ventilated by natural ventilation. During the year, the plants are inspected for the timely detection of pests and diseases. All side walls, concrete racks are smeared with lime mortar, and in the summertime glass coatings are washed with a solution of laundry detergent or soda ash. Речь об обеззараживании грунта методом пропарки либо заменой почвосмеси не может идти, так как лимоны — это многолетние насаждения.Since lemons bear fruit throughout the year, a periodic analysis of the fruits by the Sanitary Surveillance Laboratory is carried out. In this regard, generally accepted measures to combat pests and diseases are impossible in full. Once every six months, the soil is shed with a 0.1% solution of manganese-acid potassium to disinfect the soil. When transplanting plants - 1% solution.

In the unit of the domestic building there is a special unit for the preparation of solutions of fertilizers and chemical preparations. Spraying is carried out with the help of motorized, knapsack sprayers, depending on the amount of work.

In the greenhouse - lemonarii, the following pests are found: spiderweb and red mite, soft pseudo-shield, citrus whitefly, aphid, mealy larva.

Used such methods of struggle that are safe for human life:

1. Fumigation with tobacco dust. Waste tobacco factory in the form of brown powder laid out evenly throughout the greenhouse in the cans. Then they burn tobacco dust and create a smoke screen. Processing time 4 - 5 hours.

The first information on the treatment of citrus against citrus whitefly dates back to 1890, when tobacco extracts were used against eggs and larvae. This method is also used in this greenhouse.

2. Washing soap-soda emulsion. A sprinkling system of pre-prepared solution of soap and soda is supplied through the sprinkler system at the rate of 30 g per 1 liter. water. Sprinkling in each section is carried out for 3 to 5 minutes.

3. Washing the crowns of trees in the early morning with a stream of cold water.

4. Watering the soil with 0.1% potassium permanganate solution.

An important event that ensures healthy growth, normal development and good fruiting of lemons is the fight against diseases and pests.

Citrus diseases can be divided into three groups:

Black. The disease is caused by black sooty fungi, which most often develop on sticky, sweet secretions, insects (aphids, whiteflies, thrips, flaps, worms). The disease is not dangerous for the plant, but spoils its appearance: on the affected organs of plants there is a raid in the form of dark brown or black spots, like powder, because called "soot". A bloody deposit clogs the stomata on the surface of the leaf blade and thus makes it difficult to plant photosynthesis. The plant weakens, its growth slows down.

Control measures: “soot” is washed off with a wet swab from all leaves, and then the entire plant is washed under a strong warm shower, and not only remains of soot are removed, but also insects and their excretions that caused the disease. Therefore, the first step is to start fighting insects.

mobile on citrus

Leaf spot. The causative agents of the disease are many parasitic fungi. The disease is manifested by the spread of dark weeping spots of irregular shape over the leaves. In the later stages of the disease, the spots merge, affecting the entire leaf. If untreated, the disease can spread to the stems of the plant.

Control measures: the affected leaves are removed, the plant is treated with a systemic fungicide, the lemon is not sprayed for several weeks, the volume and frequency of watering drastically reduce

Citrus leaf spotting

Anthracnose. It affects leaves, shoots, twigs, and sometimes fruit. Light brown round spots appear on the leaves already at the beginning of the first spring growth. In the future, on the spots from the upper side there are black dots - fruit-bearing mushrooms. The disease leads to falling of leaves and drying of the shoots. Various adverse conditions contribute to its development: cold winters, excess moisture, lack of food

Control measures: pruning of affected shoots, gathering and destruction of fallen sick leaves, prikopka pristvolny circles and row spacing. Spraying 1% Bordeaux liquid

Anthracnose on citrus

Mealy dew. Fungal disease, which manifests itself in the form of white mealy plaque on the leaves. As a result, the leaves curl, turn yellow, the plant growth slows down. This disease, like anthracnose, rarely affects indoor lemons.

Control measures: the affected leaves should be removed and the rest of the plant should be sprayed with a solution of copper sulfate (5 g of copper sulfate per I liter of water)

Gommoz- infection. The disease is characterized by the formation of small cracks on the cortex and the expiration of gum from them, especially at the root collar. These cracks gradually widen to the size of wounds, the bark on the affected areas gradually dies off.

As it dries, the bark falls, exposing the wood. Often the disease spreads up the trunk, can go to the root, causing growth and dying of the cortex. This disease can cause the tree to die. Sick trees have yellowish foliage and this is different from healthy ones.

The main causes of hommoses are mechanical damage, frost damage, heavy, highly moistened soils, and deep planting.

Control measures: elimination of the causes of gommoz. When a gommosis appears, thoroughly clean the affected areas to healthy wood, followed by disinfection.

Gommoz on citrus

Scab (wartiness). It affects fruits, leaves, branches. At the beginning of the development of the disease, very small warts appear on the underside of the leaves, flat on top and slightly depressed in the center, pinkish yellow, brown or brown. Affected leaves fall. In the center of the growth of fruiting appear mushrooms in the form of plaque.

Control measures: prevention of spraying with a 1% solution of Bordeaux liquid and destruction of affected tissues.

Scab on citrus

Chlorosis non-infectious. The disease manifests itself in yellowing leaves. Patients with chlorosis plants weaken, are stunted and may die. Chlorosis can be caused by a lack of zinc iron in the soil, an abnormal water regime, and a strong, prolonged drought.

Control measures: elimination of the causes of the disease, and application of full mineral fertilizer in combination with micronutrient fertilizers for diseased trees. With a high standing of groundwater it is necessary to drain the soil.

It is also recommended spraying chlorotic trees (without leaves) in the early spring period with a 10% solution of ferrous sulfate or introducing this drug into the soil at a rate of 150 g / m 2

Viral diseases, so called virosecaused by infection of plant cells by intracellular parasites - viruses. Currently, about 300 forms of viruses that infect plant cells have been described. Determining the defeat of a plant by a virus is quite difficult, since As a rule, the plant does not die, and the external manifestations of the disease are very similar to the manifestations of nutrient deficiencies: a slowdown in plant growth, leaf discoloration and deformation, curvature of the stems, etc. Most often, viruses are transmitted by insect pests (thrips, aphids, etc.), as well as fungal spores.

Control measures: there is no effective treatment. In order to prevent the spread of the disease to other plants, the diseased lemon will have to be destroyed.

From the foregoing brief overview of diseases, it follows that one of the ways to treat most diseases is to spray the affected plants with systemic fungicides.

Fungicides - This is a group of pesticides that suppress the development of plant pathogens and are used to control them. According to the type of action on the causative agent, fungicides are divided into protective (preventing infection) and curative, causing the death of the pathogen after infection of the plant, and according to the distribution pattern in the plant, to contact and systemic. After their spraying, contact fungicides remain on the plant surface and cause the death of the pathogen when it comes into contact with them. Systemic penetrate the plant and inhibit the development of the pathogen due to direct exposure to it, protect the new growth. The spectrum of action of fungicides varies: from drugs acting on pathogens of many diseases, to poisons with an exclusively selective effect. For humans, most fungicides have a low toxicity, however, the treatment of plants with fungicides should be carried out with the mandatory use of personal protective equipment.

In addition to diseases, citrus fruits are attacked by pests:

Red Citrus Mite. Adult red mite, body size 0.3 - 0.4 mm. Damages all citrus fruits. Settling in bulk on the leaves, the pests suck out the juices, first causing leaf blush and then yellowing and dropping them, which leads to a decrease in yield and general oppression of the plant. The pliers also damages the fruit.

Control measures: sulfur preparations.

Red Citrus Mite

Brown shield. The adult female has a rounded shield with a convex middle, light or reddish-brown. Diameter of a guard is 1,5 - 2 mm. Larvae and adult insects do not settle on the upper side of the leaves, on fruits, and sometimes on young shoots. Whitish and yellowish spots are observed in the places of damage, merging together during mass infection with the shield. Infected fruits and leaves are showered. Shoots and branches with a strong infection die.

Control measures: spraying of plants with a 2% solution of mineral-oil emulsion prepared in soft oil (transformer oil) during the resting period of plants.

Soft pseudo shield. It is a polyphage that infects citrus and other subtropical and tropical plants in greenhouses and greenhouses. The body of the female is asymmetric, broad-oval, flat, 3–4 mm in length, of yellowish-brown color. Males and their nymphs are little known. Larvae and females settle on the leaves, most often on the veins, as well as on the stems. Cause deformation of the leaves and shoots, sometimes their abscission. The female can lay up to 1000 eggs and in greenhouse conditions it can develop in 6-7 generations.

When lemons were grown, agrotechnical measures aimed at preventing the penetration of pests into closed ground proved effective. Among biological means of protection, the cow of cryptolemus (Cryptolaemus montrouzieri Muls.) Is especially effective, which Lazarevskaya Experimental Plant Protection Station is engaged in breeding. It takes root in Ufa lemonarias. Of the chemical drugs used Aktellik, sometimes karbofos and mineral oils with soap.

Mealy Citrus Worm. Polyphage One of the most serious pests of citrus. It populates the young shoots, causes twisting of the leaves, goes to the fruit, causes them to fall, forms cracks in the fruit.

Itself is light crimson, covered with a white powdery wax, up to 4.5 mm long, 2.5 mm wide. Lives on trunks, branches, leaves and fruits, develops in three generations, the fertility of more than 600 eggs.

Countermeasures: the same as for the soft false scale.

Mealy Citrus Worm

Citrus whitefly. It causes great harm to citrus. Harm from the whitefly in sucking the juice from the leaves, which causes their oppression and falling off. The leaves, covered with black bloom, lose the normal physiological process, which worsens the general condition of the plant.

With the mass development of plants, photosynthesis slows down, the commodity value of fruits decreases. Imago (1.6 - 2.0 mm) with two pairs of white wings. Develops on the underside of young leaves, fecundity up to 200 eggs. The agrotechnical methods of struggle include the mechanical treatment and sterilization of the soil, disinsection, trapping with the help of yellow glue traps. Chemical methods are the use of actellica, pegasus, etc., biological agents are also used - parasites of the genus Encarsia and biological preparations based on the fungi of the genus Ashersonia, etc. with a low density of pests.

Pest and disease control measures are aimed at the limited use of chemical methods.

The biological method, safe for human life and environmentally friendly, is the use of insects that eat pests.

Citrus Aphid. Sedentary sucking insects, winged and wingless, ranging in size from 1 to 5 mm. The body of the aphid has a very delicate outer cover of the most diverse colors. It feeds on the soft tissue of the plant and usually attacks tender leaves, young shoots with a succulent tissue, buds and flowers. Insects multiply rapidly.

Control measures: the use of conventional pesticides: thiofol, anabasinsulfate and others in normal concentrations.

Thrips. Tiny insects with an elongated body (no more than 1 mm). They have two pairs of membranous wings bordered with long black or brown hairs. Pests lay eggs in the tissue of the leaves, the larvae come out for 8-10 days. Climbing from leaf to leaf, thrips leave behind characteristic silver streaks. Their reproduction contribute to the heat and dry air.

Symptoms of infection: flowers become stained and deformed. On the leaves first appear numerous bright spots, then the leaves fade and fall off. The growth of the whole plant slows down.

Control measures: the same as when infected with aphids, mites and flaps.

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