Why do mandarin leaves turn yellow: causes of the disease and what to do

There are many reasons why the leaves of a room tangerine turn yellow. It is difficult for a beginner to understand them. The appearance of the plant reflects maintenance and care errors. Leaves may turn yellow and fall off due to disease or pest infestation.

Causes of plant diseases

There are several reasons why indoor mandarin sheds leaves, does not bloom, lags behind in development. All of them relate to care and living conditions. The tree loses its leaves if it lacks sunlight. The pot with the plant must be moved to another, more lit place.

Sudden changes in air temperature have a negative impact on immunity. Citrus fruits love when a pleasant microclimate is created around them. Humidity and air temperature are constant, there are no drafts.

In some cases, the appearance of dry, yellow leaves on a tangerine indicates pests that have settled on the plant.

The appearance of citrus fruits suffers from scale insects, spider mites. Insects oppress the tangerine, take away its nutrients, undermine the immune system.

The soil fertility affects the condition of the tree. Over time, it decreases. Mandarin can get sick, stop developing if it is not transplanted annually into another container. The appearance is affected by the wrong mode of watering, lack or excess of moisture. An analysis of these factors will help to find out the exact reason why the tangerine turns yellow.

Possible mandarin diseases by symptoms

Diseases that occur when growing tangerines can be caused by poor care, unbalanced nutrition. They are manifested by drying, twisting of leaves, lack of fruits, their bad taste, drying of ovaries.

Leaves are falling

A plant has gone dormant if it sheds its leaves from October to February. There are no reasons for concern. Mandarin must be moved to a cool room (15 ° C) until March, reduce the volume and frequency of watering.

Reasons that require adjustment:

dry air;
large pot;
when planting deepened the root neck;
the soil is poor, it lacks potassium;
poor lighting;
drafts;
waterlogged soil.

The air is humidified with the help of household devices (humidifiers), by spraying the crown with water. Planting flaws are corrected, providing the tree with an optimal microclimate. For good nutrition, tangerines are fed with potassium nitrate.

The lack of natural light is made up for by artificial lighting.

Mandarin does not bloom

You can stimulate the flowering of a grafted mandarin with simple measures. Organize a “cold” wintering for him at the end of winter. In the spring, create high-quality artificial lighting. This is enough to form fruit buds.

Leaves turn yellow

Yellow spots that appear on the lower leaf plates indicate a lack of nitrogen. Yellowness will also cover the upper part of the crown if the tangerine is not fed in time with urea or other nitrogen-containing fertilizer.

Pale yellow color of young leaves is a symptom of chlorosis. The reason is iron deficiency. Eliminate the problem with iron chelate. They are fed mandarin 1 time per month. Poor storage conditions (small pot, poor lighting) also cause yellowing.

Fruit falls

It's not always clear what to do when the tangerines fall off. A common cause is a viral disease. The small ovary often falls off due to the shield. Nut-sized fruits fall off if containment is breached:

dry air;
bright sun;
enhanced nitrogen fertilization at the time of ovary formation;
underwatering or overwatering.

Leaves dry

Mandarin dries up due to improper watering. A sign of waterlogging is a dry brown border on the leaf plates. The tree must be replanted to save it from death. Cut off rotten roots. Pour drainage into the container. Prepare a breathable soil mixture. Most of it should be leaf ground.

The dried plant is reanimated according to the following scheme:

put in a basin of water;
watered from above until the soil is completely moistened;
remove excess liquid (drain);
the crown is sprayed with Epin.

Treatment with stimulant is repeated every 2 weeks.

Leaves curling

Aphids are becoming a common reason why indoor mandarin leaves curl. If there are no insects, then perhaps the earth in the pot is dry and the plant simply does not have enough moisture.

White bloom

When severely infected, the surface of the leaf blades becomes covered with a sticky layer. The growth of the plant is inhibited, the leaves fall off.

Mandarin diseases

Homemade mandarin is prone to viral and bacterial diseases. Illiterate care leads to them, proximity to diseased plants, insects.

Gommoz

Another name for the disease is gum disease. In the initial stage, spots of red-brown color appear on the surface of the trunk, branches. The bark under them dies, gum is released from the wounds. There are many possible causes of the disease:

deepened during landing;
poor drainage;
unbalanced top dressing, nitrogen predominance;
mechanical injury to the cortex.

Damaged places are cleaned, treated with copper sulfate (3% solution), covered with garden pitch.

Psorosis A or xylopsorosis

It's a viral disease. The bark is suffering. A diseased tree cannot be treated. The plant is destroyed. Symptoms are similar to gommosis. At home, it is difficult to establish an accurate analysis.

Tristesa

With this viral disease, the bark of the tangerine tree dies off. At first, the disease is manifested by a change in the color of the leaves. They become bronze. Over time, the crown becomes bare. The virus infects branches and fruits. They crumble before ripening. The root system also suffers. Mandarin cannot be cured.

Leaf mosaic

The pattern in the form of strokes and stripes on the leaves of mandarin. With the progression of the disease, their deformation and shedding occurs. The disease has no cure.

Citrus cancer

The disease is bacterial in nature, there is no cure. Signs of cancer - dark spots of bright brown color on the peel of the fruit, on the leaves.

Tangerine tree pests

Any harmful insect that has settled on a houseplant is harmful. The tangerine tree has many enemies. An infected plant can be easily recognized by its depressed appearance, yellowed, deformed leaves.

Shield

From scale insects mandarin is sprayed with soapy water. It is prepared from water (3 l) and Fairy (2 tbsp. l). In case of severe infection, the tree is treated three times with Actellik. An insect of 3 types attacks a houseplant:

yellow orange;
orange with shield;
rod-shaped.

The scale insect larvae suck out the juice, their secretions create a film on the surface of the leaves, disrupt breathing.

Spider mite

This insect attacks the tangerine, if it is not watered in time, the soil is too dry. Pests are collected by hand, the leaves are wiped with a cloth dipped in cold water. Treat the crown with an infusion of garlic. Acaricides (Vertimek, Fitoverm) are effective.

Greenhouse thrips

This flying pest feeds on pollen, nectar, leaf juice.The length of an adult is 1.5-2 mm. The females are grey, the males are black. High humidity and air temperature create favorable conditions for the reproduction of thrips. Tangerines from an insect are sprayed with insecticide 3 times with an interval of 2 weeks.

Whitefly

Mandarin leaves damage larvae. They are green, settle on the back side of the leaves. The butterfly itself is small, covered with a light bloom. The color of the body and wings is white-pink. The crown from the insect is treated with bioinsecticides:

"Aktofit";
Bicol.

Mealybug

Adult has a body length of 3-6 mm. The threat to the mandarin is their larvae. They are mobile, suck the juice of young shoots, leaves, buds. You can find out about the pest by sticky white secretions. The insect carries the infection - sooty fungus.They fight the pest with a solution of "Karbofos" (for 1 liter of water, 5 g of the drug). With an interval of 7 days, 4 treatments are carried out.

Aphid

Adults 1-3 mm long settle on the back side of leaf blades. Affected leaves curl and dry. Fight aphids with folk methods:

an oil-soap emulsion is prepared from machine oil and soap (1 liter of water, 1 tbsp. oil, 1 tbsp. liquid soap);
tree is sprayed with tobacco infusion;
treat the leaves with infusion of ash.

Garden slug

The leaves are suffering from a gluttonous insect. Fight it with traps and drugs:

"Meta";
"Throw Snakol";
Ferramol.

Earthworms

Worms are driven out of a pot with mustard. Its solution (1 liter of water, 1 tsp of powder) is watered over the soil. Single specimens do not harm the plant. A large number of earthworms inhibits the plant, inhibits growth.

Citrus Nematode

The tangerine root system suffers from small milky worms. Lesions look like small blisters. The nutrition of the plant is deteriorating, this is reflected in its immunity and appearance. Growth slows down, the number of ovaries decreases, and the risk of fungal diseases increases.

Disease and pest prevention

A tangerine tree infected with a virus cannot be cured. The only way to fight is prevention. The following measures prevent diseases:

creating an optimal microclimate;
feeding;
regular watering;
system inspections of the tree, removal of damaged branches, leaves.

In order to prevent viral, fungal and bacterial infections, modern biofungicides are used. The soil is watered with a solution, the crown is periodically sprayed.