Mandarin diseases and how to overcome them

Citrus Diseases, which include mandarin, to some extent specific, and in some characteristic of many fruit plants. In most cases, tangerine tree diseases are caused by microorganisms: mycoplasmas, viruses, bacteria, fungi. The result of their actions are various defects on the tree and fruits: growths, ulcers, rot, blotchiness, and so on. They can penetrate inside the plant through the stomata of the leaf, into the wounds formed by mechanical damage, through insects, wind, by spraying or watering. The difficulty is that not all measures to combat mandarin diseases are effective, and in some cases even useless. Below we dwell on the most characteristic diseases and ways to combat them.

Anthracnose

The disease is caused by the pathogenic fungus Colletotrichum glocosponoides Penz, which develops in a moist environment and settles on fruits, leaves, and branches of a plant. Infected leaves are first covered with pale green spots that darken over time. If the infection has occurred during the rainy season, the spots may be dark brown.Black dots appear on the tips of the shoots. The branches turn completely brown, then light gray, become covered with a lot of blisters and die off. Affected flowers become covered with reddish spots and fall off. Small dark spots appear on the fruits around the pedicels, which spread and hurt the skin. It acquires a dark brown color, softens. Fetal disease can occur during storage. They have an unpleasant smell and a bitter-sour taste.

This fungal disease mandarin occurs with high humidity and improper care. In order to combat it, the affected shoots are trimmed and special fungicides are sprayed according to the instructions. It is recommended to use the biofungicide "Fitosporin", since it is non-toxic. It is added to the water for irrigation as well as the prevention of fungal diseases. For prevention, gardeners recommend spraying tangerines with a solution of Bordeaux liquid (1%) two to three times per season.

Wartiness

Another disease caused by a 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 scalls appearing on the young shoots increase and turn into an impressive accretion that 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 ovary 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 the 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.

Gommoz citrus

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 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 is reduced;
• 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 of seedlings;
• mechanical damage, because of which there were wounds, where and got an infection.

In addition to the measures described above, the following should be carried out. Clean and sanitize the wound with a solution of copper sulphate (3%). To do this, 30 g of the product 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.

Citrus Cancer

A disease caused by bacteria that infect the leaves and fruits of a tree. Manifested in the form of bright dark brown spots. Citrus cancer is not treated. The plant must be removed from the soil and destroyed.

Late blight

Most often, this fungal disease affects the tangerine trees, which 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 similar means with morehigh 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 room mandarin 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.

Tristeza

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 slowing down the 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.

Malsecco

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 goes 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 spread by 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 a leaf, its tip dries up, acquiring a rusty-brown hue, the mandarin requires additional phosphorus. If recesses and folds appear between the veins of the leaves, increase the dose of potassium. About the lack of iron, as well as zinc with manganese, says a grid of green veins on the 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 onthe plant. He begins to die off the edges of the leaves.

Mandarin - tender 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.