Diseases of potato tops damage crop and can kill plants. Such lesions have a different origin. Diseases are caused by fungi, viruses and bacteria. Depending on the symptoms, choose a method of treatment.
Causes of Potato Disease
Potato disease can be diagnosed by changing the state of the tops. Usually their pathogens are mixed from the stems to the root system.
There are various reasons why potato diseases appear:
- low resistance of varieties to pathogens;
- the presence of fungus in the soil, which affects potatoes, tomatoes and other solanaceous crops;
- high humidity and hot weather, provoking the spread of fungus;
- lack of nutrients;
- improper fertilization and watering.
Diseases of the fungal type spread malicious spores. They can be stored on the inventory, in the planting material, the old tops. The development of fungal diseases occurs at high humidity and high ambient temperatures. The main diseases of potato tops, photos, description and treatment are given below.
One of the most common and dangerous diseases of potatoes is late blight. The disease spreads to stalks, tops and root vegetables. Symptoms of late blight appear in the second half of the growing season, when the flowering of plants begins.
Late blight has the following characteristics:
- oozing spots appear on the lower leaves, which eventually turn brown;
- white bloom forms on the reverse side of the sheet;
- the appearance of solid gray spots on the tubers of potatoes.
A complex of measures will help prevent phytophtora. All of them are aimed at strengthening the immunity of plants and the destruction of the source of the disease:
- use of potash fertilizers;
- fertilizing potatoes with solutions based on boron, manganese and copper;
- spraying of seedlings with 0.2% solution of copper sulphate.
When the first signs of the disease appear, chemical protective agents are used:
- Spraying Bordeaux liquid 1% concentration. Two solutions are prepared for its preparation: on the basis of copper sulphate and quicklime. Potatoes are processed every week.
- The use of chemicals. Against phytophthora, an effective remedy is “Oxy”. A bucket of water requires 20 g of the substance. The resulting solution is spraying potatoes.
The disease manifests itself in the form of black plaque on the tubers, which is easily removed. Black scab is dangerous in that it harms potatoes destined for planting next year.
The disease is actively developing with the early planting of potatoes, when there is high humidity and low temperatures. As a result, tuber germination slows down. When exposed to black scab, seedlings become brown, ulcers appear on them.Important! Black scab causes root rot and weakened shoots.
To protect potatoes from this disease, they constantly change their landing sites. Potatoes need to be planted only after the soil is well warmed. Crop harvested only in dry weather to avoid the spread of fungus.
If disease is detected, the tubers will have to be removed The remaining roots are treated with the following drugs:
- "Ditan M-45". 0.2 kg of the substance is added to a bucket of water, after which the tubers are placed in the solution.
- Boric acid. For processing preparing a 1% solution.
One of the most dangerous diseases of potatoes is cancer. A lesion covers the tubers on which growths appear. Today, there are about 18 species of fungus capable of provoking potato cancer.
The causative agents of the disease affect different types of plants that belong to the family of the nightshade. A favorable environment for the spread of the disease is a temperature of about 20 degrees and high humidity. The pathogen retains its vitality for 30 years.Important! The lesion covers the potato tubers and the lower part of the bush.
Cancer has the appearance of growths that gradually grow and turn brown. The result is the destruction of the tuber. The causative agent of the disease spreads during the growing season of potatoes due to the formation of zoospores. The fungus is transferred to the soil with root crops, seedlings, stored on garden tools and equipment.
Quarantine measures help prevent disease progression. Material for planting is sorted, and then eliminate the affected specimens.Tip! To eliminate the foci of the disease on the potatoes help chemicals.
Soil is disinfected with 2% solution of "Nitrafen". Each square meter requires 20 liters of solution. Processing is carried out according to the instructions in early spring using protective equipment.
The disease is common in the southern and eastern regions. Dry rot can kill 40% of the crop.
Its causative agent is a fungus that infects potato tubers. The spread of the fungus occurs through infected roots, soil and plant residues.Important! Dry rot can be found at any stage of potato development, however, it is most often detected during the flowering period.
Signs of the disease are:
- the top of the bush brightens and gradually fades;
- the lower part of the stem becomes brown;
- at high humidity, an orange or pinkish bloom is detected on the stem;
- when cutting the stem, the vessels of the plant are noticeable;
- over time, the shrub of the potato wilts.
On the affected tubers grayish depressed spots spread, under which the flesh dries. In the root appear voids, in which there is a mycelium. Such tubers barely germinate and form weak bushes.
Universal remedies for dry rot do not exist. For the prevention of disease, planting material is treated with Fitosporin. To prevent the disease from spreading during the storage of potatoes, the tubers are placed in a solution of the preparation “Maxim KS” for a while.
The spread of Alternaria is observed on the stalks, leaves and potato tubers. The disease leads to a decrease in yield by 30%. Usually, the disease is diagnosed on varieties of medium and late maturation.
Alternaria has a number of symptoms:
- two weeks before flowering large leaves of brown or brown color appear on the leaves;
- with the development of the disease, the staining occurs, the tops of the potato turn yellow and die;
- on the stems there are elongated spots.
The disease is spread by insects and raindrops. When the temperature rises to 26 degrees and high humidity begins the active development of fungus on potatoes. Alternariosis is especially susceptible to weakened plants with low immunity.
To combat lesions, use chemical solutions: Kuproksat, Profit, Novozri, Metaxil, Ridomil. In order to prevent treatment, planting material is exposed.
Macrosporia is a fungal disease that affects solanaceous crops. It is determined by the following features that appear before flowering:
- small spots of gray, brown or brown on the tops of potatoes;
- spreading weak black bloom;
- with a lack of moisture, the tops gradually dry out.
The disease can also occur in the later stages of potato development. In this case, the lesions are located at the edges of the sheet and are distinguished by a rounded shape. With a high degree of development of the disease, the leaves fold into a tube.
The following methods help to get rid of the disease:
- Bordeaux mixture (during the growing season, a 1% solution is prepared, after harvesting, treatment with a 3% mixture is performed);
- polycarbocin (the working solution is prepared from 0.4 kg of the drug per liter of water and applied during budding, then the procedure is repeated after two weeks);
- potassium permanganate (10 g of substance is taken per liter of water, after which the tops of potatoes are sprayed).
Diseases of a viral nature cause irreversible changes in plant organisms. Their effects lead to discoloration and deformation of the tops. As a result, the potato has a depressed appearance and develops slowly.
The infection persists in tubers and has no external manifestations. After planting the infected material, the development process of the potato is disrupted. Distributors of the virus are bedbugs, aphids, cicadas and other insects.Attention! Viral diseases are not treatable. When alarm signs appear, bushes are removed from the site to avoid contamination of healthy plants.
Diseases can be avoided with preventative measures. This includes the choice of quality material for planting, preventive treatment of tubers and soil.
The following are the virus diseases of potato tops with a photo and description.
The disease affects the ground part of the potato and is diagnosed by the presence of mosaic stains or stripes. Dark brown stripes appear on the veins on the back of the leaf. As a result, the stems become more fragile.Important! Striped mosaic first appears on the lower leaves, and then spreads to the top of the potato.
In the final stages of the growing season, the lower leaves of the potato dry up and fall off. With the defeat of tubers on them appear bumps and rings.
Striped mosaic spreads aphid. The disease is transferred to healthy tubers through mechanical damage.
A wrinkled type mosaic appears as a leaf bulge between the veins. As a result, the leaves become corrugated.
The disease is difficult to diagnose in the first year, since its manifestations are hardly noticeable externally. After three years, wrinkled mosaic leads to a slow development of plants. This is determined by the height of the plants, which does not reach the norm.
With the defeat of mosaic in potatoes, small wrinkled leaves are observed, which are easily broken. Such potatoes do not bloom, and the process of its growing season is reduced by 4 weeks compared with healthy plants.
The potato leaves curled under the influence of the virus, which is distributed in the seed material. During the growing season, infection occurs through insects: aphids and bedbugs.
Viral damage leads to lower yields. Losses can be up to 70%. At high temperatures in the soil and air, the spread of the disease accelerates. The lack of watering also causes the appearance of twisted leaves in potatoes.
The disease is determined by the following features:
- the plant takes on a pale green color;
- tops turn yellow and pink on the back of the leaf;
- first, the lower leaves of the potato curl, after which the disease spreads to the top of the bush;
- twisting occurs along the central vein in the form of a boat;
- the sheet plate becomes rigid and breaks with any external contact.
The process of infecting potatoes can take up to two years. When twisted leaves are detected, the plant is eliminated. Torsion is not amenable to treatment, therefore, special attention is paid to the choice of planting material, periodic inspection of plantings, pest control.
Before planting, the tubers are disinfected using special preparations. This will destroy the virus before it spreads to potatoes.
In the presence of this disease, spots in the form of a mosaic appear on young leaves. They have a light green color and irregular shape. With the development of the disease, dark brown spots are diagnosed on the leaves.
The mottling pathogen is a virus that is transmitted through the interaction of healthy potato bushes with affected leaves. This occurs as a result of direct contact, through damage caused by garden tools, or insects.
Important! Eruption virus has a negative effect on leaf photosynthesis. As a result, lost up to 40% of the crop.
For the prevention of mottling, the soil is treated with phytopreparations. The first procedure is carried out after the appearance of the first shoots of potatoes. The treatment is then repeated twice during the season.
On the plot you need to remove weeds that also attract the virus. Increased attention is paid to the fight against aphids, which serves as a peddler of the infection.
This disease is of viral origin and leads to the swelling of potato tubers. As a result, they acquire a cylindrical shape resembling a spindle.
The virus infects potatoes at any stage of development. When it comes into contact with the affected leaf, the disease spreads to the leaves and stems of the plant. The pathogen can dwell in the soil, it carries bugs, Colorado beetles and grasshoppers.
Gothic can be determined by a number of signs:
- small leaves, located at an acute angle to the stem;
- shoots of potatoes do not branch;
- after flowering the tops turn yellow;
- in the second year, the affected plants do not give inflorescences;
- potatoes contain an increased number of eyes;
- in a drought, the tubers will crack and become stained.
Gothic appears on all varieties of potatoes. For the prevention of disease after harvest in the area oats and rye are planted. The root system of these plants has the ability to disinfect the soil.
The virus can be stored for up to two years in the garden inventory. In the soil, the viability of the pathogen persists for two months.
Bacterial diseases may not manifest for a long time. Malicious bacteria are usually found in planting material that looks outwardly healthy. The disease is detected after planting potatoes, when violations occur in the process of its development.
The disease develops on the seedlings of potatoes, the tops of which are beginning to fade. As a result, the leaves turn yellow and gradually bind. The stem of the potato turns black and is easily pulled out of the ground.Important! If the black leg has spread to young plants, this potato does not form new tubers.
At high humidity, the black leg extends to adult plants. When the stem decays, its tissue becomes dark green in color, cavities appear on it, and vessels turn black. The distributor of the disease goes to the formed potato tubers.
With the defeat of the black leg is lost up to 80% of the crop. Infected root crops cannot be stored because they rot quickly. If the disease has spread to healthy tubers, then weakened plants result.Important! Black leg is determined by the black stems and fallen leaves.
Infection spreads at low temperatures and high humidity. When adverse symptoms are detected, the plants are removed from the site. Healthy plants are treated with a solution of potassium permanganate at a concentration of 3%. Potatoes can be sprinkled with ashes.
Disease Ring rot is quite slow. The following symptoms are observed:
- the leaf turns yellow;
- stems gradually wither and fall to the ground.
Ring rot continues until the potato harvest period. The development of the disease provokes drought and hot weather. With the defeat of the tuber is the yellowing of the vascular ring, its softening and turning.Important! Ring rot spreads through damage on tubers or if not properly stored.
When a disease is detected, the affected bushes are excavated and burned. Warming up the seed will help prevent ring rot. The disease manifests itself when the temperature rises to 18 degrees. Soft tubers of potatoes, on which black hollows have appeared, are not used for planting.
Avoid ring rot will allow the correct choice of landing site and the use of quality material for planting. Fertilizers based on nitrogen and potassium are required to help strengthen the immunity of potatoes.
With the timely implementation of preventive measures can significantly reduce the likelihood of the spread of disease.
Prevention measures for potato diseases are as follows:
- The choice of varieties resistant to pathogens. It is best to choose varieties obtained specifically for your region. They take into account the composition of the soil and the climatic conditions of the area.
- When signs of disease are found, curled leaves and other affected parts must be destroyed by burning.
- Compliance with the rules of crop rotation. Potatoes are recommended to be planted in places where cabbage, pumpkin, cucumber, legumes were previously grown. It is forbidden to plant on the beds, where previously grew sunflower, solanaceous crops.
- Processing tubers before planting. The use of special preparations allows to destroy the sources of the disease that inhabit the planting material. For these purposes, suitable "Fitosporin", "Prestige" or "Maxim". First, prepare the working solution according to the proportions indicated on the package. Potato tubers immersed in it for 15 minutes.
- Timely care of plantings. This includes hilling plants, watering and feeding.
It is possible to reveal the development of diseases by the external state of the potato: the leaves begin to curl and turn yellow, spots appear on them. As a result, the development of plants slows down and the crop is lost. Protecting potato plantations from diseases will help compliance with agrotechnics and the choice of high-quality tubers for planting. Periodically need to process potatoes for the prevention of disease.