Diseases And Pests Of Lemon: What To Do If Leaves Fall, Tips Dry And Others

2024 Author: Bailey Albertson | [email protected]. Last modified: 2023-12-17 12:53

Strong Homemade Lemon Health

Lemon is an evergreen citrus plant cultivated in the tropics and subtropics. In Russia, it is grown in room culture or in heated greenhouses, with the exception of the Black Sea coast of the Caucasus. Due to the high demands on the conditions of the habitat, with inept care, the plant often gets sick and is attacked by pests. But for those who want to try their hand at growing this fruit, there are problem-solving algorithms.

Content

• 1 Diseases of lemon: description, prevention and treatment

  • 1.1 Chlorosis
  • 1.2 Anthracnose
  • 1.3 Sooty fungus
  • 1.4 Scab
  • 1.5 Powdery mildew
  • 1.6 Phylostictosis (brown spot)
  • 1.7 Citrus Cancer

• 2 Lemon pest control

  • 2.1 Shield

    2.1.1 Video: a simple method to get rid of the scabbard

  • 2.2 Aphids
  • 2.3 Spider mite
  • 2.4 Mealybug
  • 2.5 Legs (podura, collembolans)

• 3 Diagnosis of diseases and pests of lemon by characteristic features

  • 3.1 Leaf problems

    • 3.1.1 Leaves are falling off
    • 3.1.2 Video: how to help a lemon if its leaves fall
    • 3.1.3 Dry and (or) blacken the tips of the leaves
    • 3.1.4 Leaves wrinkle
    • 3.1.5 Small wavy leaves
    • 3.1.6 Wart on lemon leaves
    • 3.1.7 Leaves are cracking
    • 3.1.8 Leaves curl
    • 3.1.9 Leaves are sticky
    • 3.1.10 Leaves turn yellow
    • 3.1.11 Pale leaves
    • 3.1.12 Black dots
    • 3.1.13 Brown spots
    • 3.1.14 White spots

  • 3.2 Problems with fruiting

    • 3.2.1 Lemon does not bloom
    • 3.2.2 Video: an original way to make lemon blossom
    • 3.2.3 Lemon blooms but does not bear fruit
    • 3.2.4 Lemon fruits fall

  • 3.3 Other problems

    • 3.3.1 Lemon branches are dried
    • 3.3.2 Roots rot
    • 3.3.3 Lemon has white bugs in the soil

Lemon diseases: description, prevention and treatment

Since the lemon in our apartments grows in conditions unusual for culture, the plant is often exposed to various diseases.

Chlorosis

Chlorosis is a disease in which the formation of chlorophyll in leaves is disrupted and the activity of photosynthesis decreases. Its characteristic features:

• premature yellowing and leaf fall;
• small-leaved;
• drying of the tops of the shoots;
• dying off of active roots.

The disease is caused by a lack of iron (most often), nitrogen, magnesium in the soil, as well as excess acidity and stagnant water.

Most often, chlorosis is caused by iron deficiency in the soil.

Disease prevention consists in a balanced diet, which is achieved by using special complex fertilizers. During the treatment, root and (or) foliar dressing is carried out. To replenish iron reserves, watering with a solution of ferrous sulfate (20-40 g per 1 liter of water) is used. You can also use drugs:

• Iron chelate;
• Ferrovit;
• Ferrilene;
• Micro-Fe;
• Antichlorosis, etc.

Anthracnose

Anthracnose is a fungal disease that occurs when the pathogen spores enter the plant. This usually happens in the summer when the lemon is taken outside. Spores germinate in high humidity and cool temperatures. Lack of phosphorus and potassium also contributes to the development of the disease. The first sign of anthracnose is the formation of brown, round spots of small diameter on the leaves. In the future, the fungus can move to shoots and fruits.

Anthracnose affects leaves and fruits

Prevention of anthracnose (like other fungal diseases) consists in creating an optimal regime for the plant (air temperature within 15-25 ° C, humidity - 75-85% - it can be measured with a hygrometer) and treatment with Fitosporin-M. This is a biological fungicide (as antifungal drugs are called), absolutely safe for humans, containing humic acids, which allows you to simultaneously feed lemon. It can be used in an apartment without fear. The number of treatments is not limited, their interval is 1-2 weeks.

Treatment of the disease begins with the removal of the affected parts of the plant, then they are sprayed with stronger chemicals (Horus, Quadris). When working with them, be careful not to spill on food, utensils, etc.

Sooty fungus

Spores of soot fungus get on lemon leaves when ventilated or outdoors in summer. If the leaves are covered with sweet secretions of insects (aphids, scale insects), then this contributes to the development of a sooty fungus. At the initial stage, small islets of black soot-like bloom appear on the leaves, subsequently it covers the leaves entirely, passes to the stems and fruits. But it will not come to this if you immediately wipe the leaves with a damp cloth and treat them with Fitosporin-M. It is advisable to ventilate the room, but do not allow the plant to overcool.

A sooty fungus can be diagnosed by the appearance of a black soot-like coating on the leaves.

Scab

Scab is a common fungal disease of fruit crops that affects leaves, fruits and shoots. The first sign of the disease is the appearance of small warts on the underside of the leaves. They are flat at the top and slightly depressed at the center. Their color is from pinkish-yellow to brown or brown. The fungus itself is located in the center of the wart in the form of a plaque. Affected leaves and fruits subsequently fall off.

Scab affects the leaves, fruits and shoots of lemon

Treatment is reduced to the removal of the affected parts and treatment with fungicides, for example, 1% solution of copper sulfate or copper chloride (Abiga-Peak preparation) at a concentration of 5 g / l.

Powdery mildew

A characteristic feature of powdery mildew is the appearance of a white bloom on the leaves. As the fungus develops, the leaves curl and turn yellow, the growth of the plant slows down. In indoor lemons, this disease is a rare occurrence. The main prevention is to provide lemon with fresh air. When the first signs appear, the affected leaves are removed, and the rest are sprayed with a systemic fungicide (Horus, Speed, etc.) or a 0.5% solution of copper sulfate.

Prevention of powdery mildew of plants - providing fresh air

Phylostictosis (brown spot)

Phylostictosis is a fungal disease in which brown or dark brown spots appear on the leaves of plants. They come in a variety of shapes, often with darker edging. During growth, they cover the entire surface of the leaf, which subsequently dry out and fall off. The fungus develops at high humidity and air temperatures exceeding 25 ° C. Spores penetrate through contaminated soil or water and are carried by the wind. Prevention and treatment are common in fungal diseases.

With phyllostictosis, spots of brown or dark brown appear on the leaves of the plant

Citrus Cancer

Cancer is a viral disease that affects all citrus fruits, including lemons. The virus infects only weakened plants with low immunity. It manifests itself in the form of several swollen spots on the leaves of a dark brown color, bordered by a yellow border. As the disease progresses, branches and fruits are affected. Then the tree withers and dies.

Citrus Cancer Symptom - Brown Spots with Yellow Border

The disease is incurable, the affected plants must be destroyed. Prevention consists in good care and maintenance of the plant's immunity. You can periodically (once every 2-3 months) rinse the leaves with a weak solution of potassium permanganate.

Lemon pest control

Pests, of course, attack indoor lemon much less often than garden plants, but such cases do occur periodically.

Shield

The body of the scale is covered with a dense shield. This pest on lemon looks like a waxy coating 3-5 mm wide and thick. Usually pests are located on lateral shoots, stem and back of leaves, where they feed on plant cell sap, thereby weakening it. In the process of vital activity, insects secrete a sweetish sticky liquid that covers the leaves and shoots. It is an excellent breeding ground for sooty fungus, besides, it seals pores, disrupts plant respiration and photosynthesis. As a result, flowers begin to dry up, ovaries fall off, the plant may die.

Scabbards secrete a liquid on which soot fungus develops well

To destroy the pest, insecticides are used (drugs to combat harmful insects). Better to use proven ones like:

• Aktara. Safe for humans. After spraying, the scabbard dies within a day, and the protective effect of the drug lasts for a month.
• Fitoverm. It has a contact-intestinal action, causes paralysis and death of the pest 2-3 days after treatment. The maximum effect is achieved after 7 days. Does not accumulate in leaves and fruits, waiting time - 48 hours.
• Actellic. It has a very fast effect. After treatment, insects will die in 10-120 minutes. But you can only use it outside because of the pungent smell.

You can also use solutions according to folk recipes:

• One onion is chopped and infused for 6-8 hours in 1 liter of water. Leaves and shoots are wiped with a filtered solution.
• Similarly, 5 chopped cloves of garlic are insisted in a glass of water, then filtered and used for wiping.
• Whisk 10 g of soap in a glass of water and add 30 g of machine oil. A plant sprayed with such a composition is left for 12 hours, after which it is rinsed with warm water.

Video: a simple method to get rid of the scabbard

Aphid

There are many varieties of aphids in various colors. As a rule, aphid of light green or yellow-green shades settles on lemon, so it cannot always be found immediately after appearance. It is located on the inner surface of the leaves, where it feeds on their juice. Aphids give off a sweetish sticky liquid sometimes called honeydew. This liquid, in turn, attracts ants to itself, which happens in the summer when the plant is taken outside. Honeydew is also a breeding ground for sooty fungus. With severe damage, the leaves curl, insects occupy not only the inner surface of the leaves, but also the outer, as well as the tips of young shoots.

Aphids of light green color often settle on lemon.

If a pest is found, first of all, you should try to get rid of it by bathing the plant in warm soapy water. The rolled leaves should be cut off, and the rest can be sprayed with insecticides or folk remedies.

Spider mite

A spider mite is a very small (0.3-0.6 mm) arthropod arachnid that has many varieties. On lemon, a red mite with dark green larvae is more common. Ticks settle on the underside of the leaves, pierce them and suck out the juice. In places of punctures on the front side, small yellow spots are formed, by which the pest can be diagnosed.

You can determine the presence of a spider mite by the presence of small dots on the front side of lemon leaves

To combat ticks, acaricides (anti-tick drugs) and insectoacaricides, for example, Actellik and Fitoverm, are used. Demitan is also popular, which destroys not only ticks in the mobile stage, but also damages their eggs. The protective effect after treatment lasts for 60 days. The drug is slightly toxic to animals and bees, but dangerous to fish. Apply it once a year.

Mealybug

Mealybug is a small sucking insect (usually 3-6 mm, but there are varieties in the range of 0.5-12 mm). It got its name from the white, cotton wool-like secretions that resemble flour. Like other suckers, the bugs feed on the sap of leaves, shoots, buds, and the citrus mealybug also affects the root system.

Mealybugs feed on the juice of leaves, shoots, buds

The worm is afraid of moisture and loves dry conditions. Therefore, plants kept in a humid environment, regularly rinsed with warm water, are rarely affected by the worm. And even if the worm has already hit the plant, it is easy to get rid of it by washing the leaves with soapy water, followed by spraying with tobacco infusion, garlic infusion or cyclamen broth. You can also apply insecticide treatments.

Legs (puffs, collembolans)

Legs are small (about 2 mm) white (can be beige, red, gray) arthropods, which often grow in the soil under indoor plants. This happens when the right conditions are created for them:

• excessively moist soil and poor drainage;
• damp indoor or greenhouse air;
• moss;
• excess organic matter;
• rotting residues of natural fertilizers;
• low room temperature.

Most often, springtails enter the room with soil or through ventilation grilles. They actively move in the upper soil layer and on its surface, they can jump. If there is not enough organic matter for nutrition, then insects can eat small lemon roots, which will lead to its disease.

Leopards are often found in the soil of indoor plants.

It is possible to get rid of sugars by spraying the soil with insecticides (Aktra, Iskra, Decis, etc.), but it is quite possible to do without the use of chemicals. Some ways:

• The easiest way is to place the pot in water. The leopards will float up and all you have to do is collect them. It is important not to harm the lemon. The water should be warm, at room temperature, and as a result of manipulating the pot, the spatial arrangement of the plant cannot be disturbed.
• Replace substrate and drainage.
• Cut open the raw potato and place the halves on the soil, slices down. After a few hours, an accumulation of pests forms on them, which should be destroyed and the procedure repeated.
• Spread dried lemon and orange peels on the soil surface. Their smell will drive the springtails away.
• Sprinkle the soil with wood ash with a layer of 10 cm, for a while reduce the dosage of water during irrigation.

Diagnosis of diseases and pests of lemon by characteristic features

In the fight against diseases, it is important to accurately recognize and diagnose them. Sometimes it is not quite simple and requires certain knowledge and experience.

Leaf problems

The main indicator of a lemon's health is its leaves.

Leaves are falling

Since lemon is an evergreen plant, seasonal leaf fall is not characteristic of it. As a rule, this is a reaction to various stressful situations:

• Lack of light. In winter, lemon needs additional lighting to extend daylight hours to 12-14 hours. It is better to use economical fluorescent lamps that do not heat or dry the air.
• The air is too dry and hot. Do not place pots of lemons near heating appliances. To humidify the air, use special humidifiers or place wide containers with water near the plants.
• Excess or deficiency of moisture. Soil moisture should be constant and moderate. Deviations in any direction will lead to falling or yellowing of the leaves. Water the lemon when the soil dries up to a depth of no more than 2 cm.
• Root decay (more on this issue below).
• Nutritional deficiency due to soil depletion. The plant constantly needs both basic elements (nitrogen, phosphorus and potassium) and trace elements. Lack of any substance first leads to a change in the shape and (or) color of the leaves, and then to their fall. Therefore, feeding should be done regularly at intervals of 7-10 days.
• A sharp temperature drop. The plant was moved from cold to warm or vice versa - the lemon does not like this and immediately sheds its leaves. If it is necessary to move, the rise / fall of temperatures should be smooth.
• Coldness in the room where the tree hibernates. In winter, lemon needs a cool temperature, preferably between 12-16 ° C, if it drops below 10 ° C, it is stressful and causes the leaves to fall off.

Lemon leaves fall for different reasons.

Video: how to help a lemon if its leaves fall

The tips of the leaves dry and / or turn black

Dry leaf tips are caused by:

• The air is too dry.
• Very high or low air temperature.
• Using tap water for irrigation. It contains chlorine, fluorine, and it can be too harsh. Lemon should be watered with rain, melt, filtered or bottled water. If you still have to use tap water, then it should first be defended for 3-5 days.
• Strongly compacted potting soil.
• Deficiency or excess of moisture.

Lemon leaf tips dry out due to dry air, dense soil, lack of moisture

Leaves wrinkle

Lemon leaves begin to wrinkle with a lack of potassium. If you do not feed the plant in time, this will lead to edge burns of the leaf, death of tissues, then drying out and withering away of the branches, and a decrease in the crown. To eliminate the problem, the plant is watered at the root with solutions of potassium-containing fertilizers (potassium sulfate, potassium monophosphate) at the rate of 5 g per 1 liter of water. Additionally, foliar feeding is carried out by spraying the crown with the same solution, but half the concentration. The procedure is repeated after 7-10 days.

Leaves shriveled in lemon due to potassium deficiency

Small wavy leaves

Shredding of young leaves can occur when there is a lack of nitrogen and / or phosphorus. If in the first case the leaves turn yellow, in the case of a lack of phosphorus, they acquire a dark green, bluish, dull color. With a lack of nitrogen, the plant will recover rather quickly after adding a sufficient amount of urea or ammonium nitrate (2-3 g per 1 liter of water). And in the case of a phosphorus deficiency in a plant at an early age with poorly developed roots, it is almost impossible to eliminate the negative effect of this deficiency by abundant watering with a fertilizer solution. Adult plants will recover quite normally after applying a superphosphate solution under the root in an amount of 5 g per 1 liter of water.

Leaves become smaller and wavy due to lack of nitrogen and phosphorus

Wart on lemon leaves

This symptom indicates a possible infection of the lemon with scab.

The leaves are cracking

With a lack of calcium, young leaves at the ends of the shoots first brighten, curl downward, the leaf plate at the fold often breaks. Then the tops and edges die off, the leaves fall off. In this case, you need to add slaked lime (fluff) or ground chalk. But this should be done carefully, as excess calcium is also harmful. It is better to pre-measure the acidity of the soil with litmus paper. If the pH is below 5.0, then take 1 tsp. with a slide of fluff (or chalk), dissolve in water and water the plant. Then measure the acidity of the water flowing out of the drainage holes, if necessary, repeat the procedure. As a result, the acidity should be at a pH level of 6-6.5.

Leaves curl

This common problem can have the following reasons:

• Lack of moisture, too rare watering and spraying. In the summer, this should be done daily, but not allowing the soil to become waterlogged.
• Lack of fresh air. The plant with the onset of stable heat should be taken outside, but it should be placed in places without drafts and protected from direct sunlight.
• Boron deficiency. In this case, young shoots and leaves curl up, as with a lack of moisture, but after watering the situation does not change. The plant should be fed with complex fertilizers or 0.2% boric acid solution (2 g per 1 liter of water).
• Copper deficiency also causes lemon leaves to curl up, but in this case, it curls up in an arc. Foliar top dressing with a 0.5% solution of copper sulfate will solve the problem
• Attack of aphids or ticks.

If the lemon leaves are curled up in an arc, then they should be sprayed with a 1% solution of copper sulfate

Leaves are sticky

The sticky coating on the leaves is a sugar syrup that is released from them during excessive watering. In this case, it is easy to get rid of the phenomenon - you just have to normalize the degree of plant moisture. In addition, a sweetish sticky coating can be the secretions of pests - aphids or scale insects.

Leaves turn yellow

This common occurrence can have many reasons:

• Nutrient Deficiency. To avoid this, you should regularly feed the lemon with complex fertilizers.
• Violations of the heat and humidity regime.
• Insufficient lighting.
• Root damage, root rot.
• Chlorosis is a disease caused by a deficiency of certain elements, most often iron.
• Anthracnose is a fungal disease.

Lemon leaves turn yellow due to disease, poor lighting, lack of nutrients

You can read more about this issue here.

Pale leaves

Lightening of leaves is most often caused by poor lighting, so you should not forget about arranging artificial lighting for the winter, as described above. Another common cause is a lack of manganese. To be sure of this, you need to spray the leaves with a slightly pink solution of potassium permanganate (potassium permanganate) - if after a week the leaves darken, then the diagnosis was correct. Pale leaves can also be a sign of chlorosis.

A common cause of leaf pallor is a lack of light.

Black spots

First you need to take a close look. These dots can be harmful insects such as aphids or scale insects. Also, a sooty fungus can settle on the leaves.

Brown spots

Most often, brown spots appear as a result of a lack of phosphorus. Then it is necessary to feed the plant with phosphorus in the same way as in the case of the crushing of the leaves. Also, this phenomenon can be a sign of lemon infection with phyllostictosis or citrus cancer.

White spots

White spots appear in the following cases:

• the use of cold water for irrigation and spraying;
• the result of a burn in direct sunlight;
• powdery mildew infection;
• mealybug lesion.

Diseases, pests, cold water, and burns can cause white spots on the leaves of the plant.

Problems with fruiting

There are times when a lemon bush seems to grow and develop normally, but does not bear fruit. There may be several reasons for this.

Lemon does not bloom

Many gardeners in their reviews say that a lemon grown from a stone has not bloomed for many years. Often the problem is solved by grafting a cuttings or buds from a fruiting plant into the crown of such a lemon. Some sources report cases when rooted cuttings from non-fruiting lemon bloom the next year. And, of course, a lemon (even planted with a grafted seedling from a nursery) will not bloom if the rules of its agricultural technology are not followed:

• Unsuitable soil composition.
• Failure to comply with the heat and humidity regime.
• Sudden temperature changes and its inconsistency with the required parameters. The most abundant flowering occurs at a temperature of 18 ° C.
• Imbalance in nutrition.
• Lack of illumination.

Video: an original way to make lemon bloom

Lemon blooms but does not bear fruit

This happens in such cases:

• The room is too hot and dry.
• Drafts.
• Poor pollination. It should be done manually by winding cotton wool around a match, transferring pollen from flower to flower.
• Insufficient nutrition - as a result, the ovaries fall off.
• The term for transplanting into a new pot was missed, the roots became cramped. Young plants should be transplanted up to three times a year, 3-4 year olds - once a year, at the age of 5 years and older - once every 2-3 years.
• Too abundant flowering. The plant lacks strength and nourishment for a large number of flowers and it sheds the ovaries. It is necessary to normalize at the flowering stage, leaving one bud per 10-15 leaves.
• During flowering, you cannot transfer the plant from room to room, and also turn it more than 10 ° and more often than once every ten days. As a result of such actions, the lemon can shed flowers or ovaries.

Sometimes lemon blooms do not lead to fruit formation

Lemon fruits fall

If the gardener has grown fruit of a normal size on his lemon, this indicates that the care was correct and no mistakes were made. But if suddenly already large lemons began to fall off, then, obviously, the plant was subjected to some kind of stress (drafts, temperature changes, turning the pot or moving it, etc.).

Sometimes the ovaries do not have time to ripen and fall off

Other problems

And some other problems.

Lemon branches dry

The reasons for this phenomenon, like many other troubles, may be violations of agricultural technology. Most often this is a consequence of moisture deficiency, as well as its excess. In addition, the branches can dry out if the lemon is infected with a spider mite. If, however, everything is in order with agricultural technology and pests, and the branches of the lemon still dry up in the winter, then perhaps this indicates the acclimatization of the plant. In this case, in the spring, you should remove all dried shoots, and new ones will grow instead.

Dying lemon branches signal a deficiency or lack of moisture, illness, plant acclimatization

Roots rot

Most often this happens due to excessive watering, as well as improper selection of the pot and (or) lack of drainage. If the pot is too large, the soil will sour, causing root rot. This can be determined by shedding the leaves. If at the same time the soil remains moist for a long time even in the absence of watering and dry air in the room, then this indicates that an urgent need to check the condition of the root system:

1. To do this, you need to get the plant out of the pot with a lump of earth and inspect the roots, after removing all the substrate from them and rinsing with water.

   

   In case of root decay, you need to get the plant out of the pot

2. Rotten roots should be cut to healthy tissues, the remaining ones should be treated with a weak solution of potassium permanganate by dipping the roots into it for several minutes and sprinkled with charcoal.

3. If pruning has significantly reduced the volume of the root system, then a smaller pot is chosen for planting.

   

   If the root system had to be reduced, then take a smaller pot

4. After planting, the lemon is watered abundantly and sprayed with warm water.
5. You cannot feed the plant for a month until it is completely rooted.

Lemon has white bugs in the soil

Most likely springtails are in the soil.

Growing indoor lemon is not an easy task. He will have to devote a lot of attention and time. Even minor deviations from the rules of agricultural technology often lead to serious problems. Therefore, before deciding to start a citrus plant, you need to carefully familiarize yourself with the features of its cultivation at home.