Content
Lilacs are used for decorative purposes, landscaping the site, creating a hedge. Like any plant, it is susceptible to diseases and pests. Under their influence, the shrub develops slowly and may die. Next, pests, lilac diseases and the fight against them are considered, which will help gardeners to preserve the plant.
Pests of lilacs and the fight against them
Lilac pests feed on buds, leaves, flowers, branches. As a result, shrub development slows down, fewer inflorescences appear, leaves and shoots are deformed.
Lilac moth
If lilac leaves with brown spots, this is the first sign of the appearance of a lilac moth on the site. Its caterpillars feed on the leaves of the bush, which turn brown, wrap up in tubes and die off. At first glance, the plant appears to have been damaged by fire.
Lilac moth butterflies fly out in mid-May - early June. For 5 - 6 days, the female lays several hundred eggs on the underside of the leaf. After 5 - 10 days, caterpillars appear, which destroy the leaf plate. Caterpillars of the second generation appear at the end of September. Their pupae overwinter in the soil at a depth of 5 cm.
Spraying lilacs with Inta-Vir, Iskra, Karbofos helps to fight the pest. The first treatment is carried out at the beginning of flowering and repeated after 3 weeks. Affected shoots are cut and burned.
Lilac mite
The lilac mite is a dangerous pest that is invisible to the naked eye. Its dimensions do not exceed 0.2 mm. The mite damages the lilac buds, which swell and dry out on the branches. The pest feeds on the sap of young leaves. It hibernates inside the buds and begins to multiply in early spring. Several generations appear during the season.
Spraying with Carbolineum emulsion at a concentration of 6% helps to get rid of the lilac mite. Processing is carried out in early spring. During the growing season, prepare a 0.1% solution of the drug Thiofos. Spraying is performed in June during the period of active reproduction of the pest. For prevention, lilac seedlings are kept in a barrel of water before planting.
Acacia false shield
Acacia false shield is a small insect no more than 3 - 6 mm in size. Its body is oval, dark yellow or brown in color. The larvae of the pest feed on lilac juice. As a result of their activity, the size and number of leaves that fall prematurely decrease. Shoots are deformed and dry out.
The scabbard lays eggs during May. The first larvae appear in the second half of June, the subsequent ones - in early August. The pest hibernates in the bark, cracks in the branches, at the base of the branches.
To get rid of acacia false shield, Ditox or Sumition preparations are used. Such products are effective and will not be washed off by rain. In personal subsidiary plots, universal insecticides are used - Fufanon and Iskra.
Weevil
The weevil is a small beetle that feeds on lilac leaves. After it, holes of various sizes remain in the sheet plate. The root shoots, leaves of the lower and middle tier are most affected by the pest.
During the day, weevils are in cracks in the bark or fallen leaves.The period of activity falls on the evening and night. Pests hibernate in bark or soil.
During the growing season, lilacs are sprayed with Fufanon Expert, Vantex, Inta-Ts-M preparations. The product is diluted with water according to the instructions and sprayed on the bush. Consumption of working solution is 2 - 5 liters per shrub. Good results are obtained by digging up the soil in the fall. The weevil ends up on the surface of the earth and dies when the temperature drops.
Apple comma scale
The apple scale insect is a representative of proboscis insects. The female of the parasite has a gray-brown elongated scutellum 3 mm long. Males are reddish gray, small in size. Eggs of pests are white, oblong, hibernate under the shields of dead females. The larvae appear at the end of May and spread through the bush.
The larvae adhere tightly to the shoots and form a scutellum. Under favorable conditions, the scale insect multiplies rapidly and covers most of the branches of the lilac. The shrub weakens, gives few inflorescences and is depleted.
The systemic drug Ditox helps to fight the apple scab. Pests die in the first hours after treatment. The drug is not washed off by rain. For prevention, it is necessary to thin out the crown, cut out root shoots, dry and damaged shoots.
Rose leafhopper
Rose leafhopper is a narrow insect up to 3.5 mm long with green-yellow wings. The eggs of the pest hibernate in the bark at the tops of young shoots. Larvae appear when the leaves open in late April - early May. The pest feeds on leaf juice. As a result, numerous white spots remain on the leaf plate.
To combat the pest, insecticides Ditox or Alfashans are chosen. The drugs are used in small doses. Their effect appears within a few hours after treatment. The solutions are not washed off by precipitation and remain effective in deteriorating weather conditions.
The most common lilac diseases and their treatment
Timely diagnosis of diseases will help save the shrub. The following are the most common lilac diseases and their treatment with a photo. Diseases are divided into several groups, depending on the nature of the lesion.
Fungal
Fungal diseases develop due to the vital activity of microscopic fungi. Usually, the lesion spreads in cold and wet weather. The cause of the disease is often the weakened immunity of the bush, caused by an excess of nitrogen and a lack of potassium. As a result, the plant becomes susceptible to fungus.
Types of fungal diseases of lilac:
- Powdery mildew. Has the appearance of a white bloom on the leaves of a bush. First, small white spots appear, which grow and occupy the entire surface of the leaf. Within a week, the bloom becomes dark, the shrub stops developing. The disease affects both adult lilacs and young plants. Most often, its signs appear at the end of a cold and damp summer;
- Brown spot of lilac. It appears as gray spots with brown edges. Gradually, the lesion grows, the inner part dries up and falls out. Holes remain on the leaves;
- Anthracnose. The disease is detected by brown spots on lilac leaves. Ulcers may be orange or pinkish in color with a purple border. The lesion covers leaves, stems, flowers;
- Septoria. The disease appears as light spots: yellowish or gray. Gradually, the lesion spreads and causes wilting of leaves, drying of the tops of the shoots, falling of flowers;
- Lichens. White spots on the trunk of a lilac may turn out to be lichen. These are representatives of the class Mushrooms, which often appear on old trees and shrubs. Plants with cracks in the bark and a thickened crown are at risk.Lilacs affected by lichen develop slowly and are susceptible to other diseases.
To combat lilac diseases, agents containing copper are used. This includes Bordeaux liquid, copper sulfate, Topaz, Nitrofen, Oxyhom, Ridomil, Skor. They are diluted with water and sprayed with shrubs. After 7 - 10 days, the treatment is repeated.
To get rid of lichen on lilacs, they choose a mechanical method. Take nylon brushes or wooden scrapers and gently clean the trunk of the bush. At the same time, they try not to damage the lilac bark. Then the treated areas are sprayed with a solution of ferrous sulfate at a concentration of 5%. Whitewashing of shrub trunks helps to reduce the risk of lichen infection.
Viral
The causative agents of this group of diseases are pathogenic viruses. The first symptoms appear in the spring when the lilac leaves bloom. Dark spots appear on them, mosaic, twisting is observed.
Description of viral diseases of lilac:
- Ring mottling. The disease is determined by light spots and strokes on lilac leaves. Gradually, the lesion completely covers the leaf plate. The virus is spread by pests: nematodes and whiteflies;
- Ring spot. It manifests itself in the form of rounded chlorotic spots on lilac leaves. Symptoms of the disease occur in the first half of summer and early autumn. After a year, the shoots dry out and die off. Nematodes, microscopic worms that live in the soil, become carriers of the disease. The virus also spreads with garden tools.
- Chlorotic leaf spot. This is a disease of lilac leaves, on which light patterns appear. Gradually the foliage deforms and falls off.
Viral diseases cannot be treated. If the degree of damage is weak, then the affected leaves and shoots are cut off. The shrub is fed with potash and phosphorus fertilizers. If the disease persists, then you will have to uproot the lilacs and disinfect the soil.
Mycoplasma
Mycoplasma diseases occur when special microorganisms are spread. They are intermediate between bacteria and viruses. Insects serve as carriers. Mycoplasmas penetrate plant tissues and disrupt their development.
The most common mycoplasma lilac disease is paniculate. On the affected lilac, many thin lateral shoots are formed, collected in a large bunch. This disease is also called "witch's broom". The whole tree suffers from it: the leaves become small and wrinkled, their color fades, fewer flowers appear.
In order to prevent the spread of paniculation, preventive measures are taken. For planting, choose high-quality lilac seedlings. During the growing season, the shrub is sprayed to control pests-vectors of the disease.
Bacterial
Bacteria are unicellular microorganisms that feed on plant juices and tissues. The causative agents of bacterial diseases develop when there is damage to the lilac bark. Therefore, for their prevention, special attention is paid to examining the bush, disinfecting tools, processing after trimming the shoots.
Lilac bacterial diseases:
- Bacterial shoot rot. If the leaves turn black on lilacs, this is the first sign of the spread of bacterial rot. The defeat is also detected on young shoots, flowers and buds. As a result, young and old branches dry out. Infection spreads in places of mechanical damage, and then actively spreads at high humidity;
- Necrosis. The disease destroys the lilac bark, leads to the death of shoots and the death of the shrub. Infection is facilitated by severe frosts, drought, and the spread of pests. As a result, the lilac receives less nutrition and dies.
If the first signs of bacterial rot are found, then the lilac can still be saved. The shrub is sprayed with a solution of copper oxychloride at a concentration of 5%. The affected areas are cut and burned. The treatment is repeated after 10 days.
To combat necrosis, the affected areas of the bark are carefully removed. Then the shrub is treated with fungicides. For prevention, it is important to remove fallen leaves, perform sanitary pruning. All cracks and wounds on the lilac are treated with copper sulfate. Then they are covered with a talker made of clay and mullein.
Control and prevention measures
Diseases and pests of lilacs oppress the shrub: they are also dangerous to other plants. Fighting them involves the use of various methods. The most popular of them are chemicals and folk remedies.
Chemicals are diluted with water at the desired concentration. Be sure to use personal protective equipment. Treatments are carried out in dry cloudy weather. Frequency of spraying - no more than once every 7 - 10 days.
Folk remedies are safe for plants and humans. Such methods are not limited in use and are well suited for prevention. These include infusions of wormwood, onion and garlic husks, tobacco dust, wood ash. Lilacs are dusted or sprayed with a solution.
Special measures are taken to prevent diseases and pests. This requires:
- use high-quality planting material, without defects and signs of damage;
- perform sanitary pruning of shoots;
- do not injure the bark, monitor its condition;
- remove fallen leaves in the fall;
- regularly feed lilacs with mineral complexes;
- observe the dosage of nitrogen fertilizers;
- dig up the soil in the fall;
- periodically spray the shrub with solutions of insecticides and other drugs.
Conclusion
Lilac diseases and the fight against them, given above, will help diagnose damage in time and take action. So that the shrub does not suffer from pests, they perform regular spraying with insecticides. In order to avoid the spread of diseases and insects, they observe agricultural techniques and carry out preventive treatments.
On the trunk of the lilac there are light spots, there are practically no leaves, few flower brushes. With what it can be connected? Photo is avaiable.
Hello. Write to us in the "Ask a question to the farmer" section. There is an opportunity to attach a photo.
Hello, please advise what to do with the lilac, brown spots on it, and next to the peonies also turn black and wither
How to treat the lilac in which the leaves are wrapped and the pests are not visible ??
Hello! Did the leaves change color and how do they curl? Maybe there is an opportunity to send a photo. In the Ask a question to the farmer section, you can attach.
Why do the leaves curl on the dwarf lilac. I carefully cut them before flowering and burned them. I did not find any pests. What can be treated. Thanks for the help.
Good day!
There can be several reasons for curling leaves in dwarf lilacs. And in this case, it is important to pay attention to the accompanying signs.
• There is a viral disease called leaf rolling.Most often, ornamental shrubs get sick with them. The cause of the disease is a virus transmitted by ticks. A concomitant sign of the virus is the yellowness and fragility of the lilac leaf plates. Curling in this case is manifested mainly at the edges of the leaves. The affected leaves must be cut and burned. If the disease spreads, you will have to remove and burn all the shrubs so that the disease does not spread to other trees and shrubs growing in your area.
• Mosaic. A concomitant symptom of this disease is the appearance of small specks of yellow color. With the spread of the disease and damage to the shrub in a more severe form, the leaves begin to curl. You need to act in the same way as in the previous case.
• Pests. Aphids, speckled moths, scale insects - many insects often cause curled leaves on lilacs. It is necessary to regularly remove caterpillars and pupae, and treat the shrubs with insecticides. Such drugs as Fitoverm, Fufanon have proven themselves well. If aphids have appeared on your lilac, it is necessary to fight not only aphids, but also ants. They are the carriers of aphids.
• Lack of food. This is the most common cause of curled leaves on dwarf lilacs. In this case, you need to feed the shrub with mullein infusion or complex fertilizers.