Content
Diseases of the potato tops damage the crop and can lead to plant death. Such lesions have different origins. Diseases are caused by fungi, viruses and bacteria. Depending on the symptoms, a treatment method is chosen.
Causes of potato diseases
Potato diseases can be diagnosed by a change in 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 in the soil of a fungus that infects potatoes, tomatoes and other nightshade crops;
- high humidity and hot weather, provoking the spread of the fungus;
- lack of nutrients;
- improper fertilization and watering.
Fungal diseases
Fungal-type diseases spread harmful spores. They can be stored in inventory, in planting material, old tops. The development of fungal diseases occurs at high humidity and high ambient temperatures. The main diseases of potato tops, photos, descriptions and treatment are given below.
Late blight
One of the most common and dangerous potato diseases is late blight... The disease spreads to stems, tops and roots. Symptoms of late blight appear in the second half of the growing season, when the flowering of plants begins.
Late blight has the following symptoms:
- weeping spots appear on the lower leaves, which eventually turn brown;
- a white bloom forms on the back of the sheet;
- the appearance of hard gray spots on potato tubers.
A set of measures will help prevent late blight. All of them are aimed at strengthening the immunity of plants and destroying the source of the disease:
- the use of potash fertilizers;
- feeding potatoes with solutions based on boron, manganese and copper;
- spraying seedlings with 0.2% solution copper sulfate.
When the first signs of the disease appear, chemical protective agents are used:
- Spraying with Bordeaux liquid 1% concentration. For its preparation, two solutions are prepared: based on copper sulfate and quicklime. Potatoes are processed every week.
- The use of chemicals. Oxyhom is an effective remedy against late blight. A bucket of water requires 20 g of the substance. The resulting solution is sprayed with potatoes.
Black scab
The disease manifests itself in the form of a black plaque on the tubers, which is easily removed. Black scab dangerous in that it damages potatoes intended for planting next year.
The disease develops actively with early planting of potatoes, when high humidity and low temperatures are observed. As a result, tuber germination slows down. When exposed to black scab, the seedlings become brown, ulcers appear on them.
To protect potatoes from this disease, planting sites are constantly changing. Potatoes should be planted only after the soil has warmed up well.The crop is harvested only in dry weather to avoid the spread of fungus.
If a disease is detected, the tubers will have to be eliminated. The remaining roots are treated with the following preparations:
- "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. A 1% solution is prepared for processing.
Potato cancer
One of the most dangerous potato diseases is cancer. The defeat covers the tubers on which the growths appear. Today, about 18 varieties of fungus are known that can provoke potato cancer.
The causative agents of the disease affect different plant species that belong to the nightshade family. A favorable environment for the spread of the disease is a temperature of about 20 degrees and high humidity. The pathogen remains viable for 30 years.
Cancer looks like 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, and is stored on garden tools and equipment.
Quarantine measures help prevent the development of the disease. The material for planting is sorted out, after which the affected specimens are eliminated.
The soil is disinfected with 2% Nitrafen solution. Each square meter requires 20 liters of solution. Processing is carried out according to the instructions in early spring using protective equipment.
Dry rot
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 debris.
Signs of the disease are:
- the top of the bush brightens and gradually fades;
- the lower part of the stem becomes brown;
- with high humidity, an orange or pinkish bloom is found on the stem;
- when cutting the stem, the vessels of the plant are noticeable;
- over time, the potato bush withers.
On the affected tubers, grayish depressed spots spread, under which the pulp dries. Voids appear in the root crop, in which the mycelium is located. Such tubers hardly germinate and form weak bushes.
There is no universal remedy for dry rot. For the prevention of the disease, the planting material is treated with "Fitosporin". To prevent the disease from spreading during storage of potatoes, the tubers are placed for some time in a solution of the drug "Maxim KS".
Alternaria
The distribution of Alternaria is observed on the stems, tops and tubers of potatoes. The disease leads to a decrease in yield by 30%. Usually the disease is diagnosed on varieties of medium and late ripening.
Alternaria has a number of symptoms:
- two weeks before flowering, large spots of brown or brown appear on the leaves;
- with the development of the disease, stains merge, potato tops turn yellow and dies off;
- the stems have elongated spots.
The disease is spread by insects and raindrops. When the temperature rises to 26 degrees and high humidity, the active development of the fungus begins on the potatoes. Weakened plants with low immunity are especially susceptible to Alternaria.
To combat the lesion, solutions of chemical preparations are used: "Kuproksat", "Profit", "Novozri", "Metaxil", "Ridomil". For the purpose of prevention, the planting material is processed.
Macrosporiasis
Macrosporiasis is a fungal disease that affects nightshade crops.It is determined by the following signs that appear before flowering:
- small spots of gray, brown or brown color on the tops of potatoes;
- the spread of a weak black coating;
- with a lack of moisture, the tops gradually dry out.
The disease can appear at later stages of potato development. In this case, the lesions are located at the edges of the leaf and are characterized by a rounded shape. With a high degree of development of the disease, the leaves are rolled up in a tube.
The following methods help to get rid of the disease:
- Bordeaux liquid (during the growing season, a 1% solution is prepared, after harvesting, processing is performed with a 3% mixture);
- polycarbocin (the working solution is prepared from 0.4 kg of the drug per liter of water and is used during budding, then the procedure is repeated after two weeks);
- potassium permanganate (10 g of the substance is taken per liter of water, after which the tops of the potatoes are sprayed).
Viral diseases
Diseases of a viral nature cause irreversible changes in plant organisms. Their effect leads to discoloration and deformation of the tops. As a result, the potato has a depressed appearance and develops slowly.
The infection persists in the tubers and has no external manifestations. After planting the contaminated material, the potato development process is disrupted. The spread of the virus is bed bugs, aphids, leafhoppers and other insects.
Diseases can be avoided if preventive measures are taken. This includes the selection of quality planting material, preventive treatment of tubers and soil.
Below are the viral diseases of potato tops with photos and descriptions.
Striped mosaic
The disease affects the ground part of the potato and is diagnosed by the presence of mosaic spots or stripes. Dark brown stripes appear on the veins on the back of the leaf. As a result, the stems become more fragile.
In the last stages of the growing season, the lower leaves of the potato dry up and fall off. When tubers are damaged, bulges and rings appear on them.
The striped mosaic is spread by aphids. The disease spreads to healthy tubers through mechanical damage.
Wrinkled mosaic
A wrinkled mosaic appears as a swelling of the leaf 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 visible externally. After three years, the wrinkled mosaic leads to slow plant development. This is determined by the height of the plants, which does not reach the norm.
When damaged by mosaics, potatoes have small wrinkled leaves that break easily. Such potatoes do not bloom, and their growing season is reduced by 4 weeks compared to healthy plants.
Rolling the leaves
In potatoes, the leaves curl up under the influence of the virus, which spreads in the seed. During the growing season, infection occurs through insects: aphids and bedbugs.
A viral infection leads to a decrease in yield. Losses can be up to 70%. With high soil and air temperatures, the spread of the disease is accelerated. Lack of watering also causes twisted leaves in potatoes.
The disease is determined by the following features:
- the plant takes on a pale green color;
- the tops become yellow, and on the back of the leaf - pink;
- 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 upon any external contact.
The process of infesting potatoes can take up to two years. If twisted leaves are found, the plant is removed. Twisting is not treatable, therefore, increased attention is paid to the choice of planting material, periodic check of plantings, and pest control.
Before planting, the tubers are disinfected using special preparations. This will kill the virus before it spreads to the potatoes.
Mottling
In the presence of this disease, spots in the form of a mosaic appear on young leaves. They are light green in color and irregular in shape. With the development of the disease, dark brown spots are diagnosed on the tops.
The causative agent of mottling is a virus that is transmitted by the interaction of healthy potato bushes with affected leaves. This occurs as a result of direct contact, damage from garden tools, or insects.
For the prevention of mottling, the soil is treated with phytopreparations. The first procedure is carried out after the first shoots of potatoes appear. Then the treatment is repeated twice during the season.
On the site you need to eliminate weedsthat also attract the virus. Increased attention is paid to the fight against aphids, which serve as a carrier of infection.
Gothic tubers
This disease is of viral origin and leads to the elongation of potato tubers. As a result, they acquire a cylindrical shape, resembling a spindle.
The virus infects potatoes at any stage of development. Upon contact with the affected foliage, the disease spreads to the leaves and stems of the plant. The pathogen can live in the ground, it is carried by bedbugs, Colorado beetles and grasshoppers.
Gothic can be identified by a number of signs:
- small leaves, located at an acute angle in relation to the stem;
- potato shoots do not branch;
- after flowering, the tops turn yellow;
- in the second year, the affected plants do not produce inflorescences;
- potatoes contain an increased number of eyes;
- in drought, tubers crack and become stained.
Gothic appears on all types of potatoes. For the prevention of disease after harvest, oats and rye are planted on the site. The root system of these plants has the property of disinfecting the soil.
The virus can last up to two years in gardening tools. In the soil, the viability of the pathogen lasts for two months.
Bacterial diseases
Bacterial diseases may not appear for a long time. Harmful bacteria are usually found in planting material that looks perfectly healthy on the outside. The disease is detected after planting potatoes, when violations occur in the process of its development.
Blackleg
The disease develops on seedlings of potatoes, the tops of which begin to wilt. As a result, the leaves turn yellow and gradually wither. The potato stalk turns black and is easily pulled out of the ground.
At high humidity, the black leg spreads to adult plants. When the stem decays, its tissue acquires a dark green color, cavities appear on it, blood vessels turn black. The spread of the disease is transferred to the formed potato tubers.
When damaged by a black leg, up to 80% of the crop is lost. Infected roots cannot be stored as they quickly rot. If the disease has spread to healthy tubers, weakened plants form as a result.
The infection spreads in low temperatures and high humidity. If unfavorable symptoms are found, the plants are removed from the site. Healthy plants are treated with a solution of potassium permanganate with a concentration of 3%. Potato stalks can be sprinkled with ashes.
Ring rot
Disease Ring rot proceeds slowly enough. In this case, the following symptoms are observed:
- the tops turn yellow;
- the stems gradually wither and fall to the ground.
Ring rot continues until the period harvesting potatoes... The development of the disease is provoked by drought and hot weather. When the tuber is damaged, the vascular ring turns yellow, softens and rotts.
When a disease is detected, the affected bushes are dug up and burned. Warming up the seed will help prevent ring rot. The disease manifests itself when the temperature rises to 18 degrees. Soft potato tubers, on which black depressions have appeared, are not used for planting.
Avoiding ring rot will allow the correct choice of planting site and the use of high-quality planting material. Fertilizers based on nitrogen and potassium must be applied to help strengthen the immunity of potatoes.
Prevention measures
With timely preventive measures, the likelihood of the spread of diseases can be significantly reduced.
Prevention measures for potato diseases are as follows:
- Selection of varieties resistant to pathogens. It is best to choose varieties that are sourced specifically for your region. They take into account the composition of the soil and the climatic conditions of the area.
- If signs of disease are found, curly leaves and other affected parts must be destroyed by burning.
- Compliance with the rules of crop rotation. It is recommended to plant potatoes in places where cabbage, pumpkin, cucumbers, legumes previously grew. It is forbidden to plant in beds where sunflower and nightshade crops previously grew.
- Treatment of tubers before planting. The use of special preparations allows you to destroy the sources of the disease that live on the planting material. Fitosporin, Prestige or Maxim are suitable for these purposes. First, a working solution is prepared in accordance with the proportions indicated on the package. Potato tubers are dipped in it for 15 minutes.
- Timely planting care. This includes hilling plants, watering and feeding.
Conclusion
It is possible to identify 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, plant development slows down and crops are lost. Adherence to agricultural practices and the selection of high-quality tubers for planting will help protect potato plantations from diseases. Periodically, you need to process potatoes for the prevention of diseases.
Hello! Today, July 10, 2019 I noticed the collapsed potato bushes ... several bushes with yellowed leaves at the bottom and are already preparing to fall apart too (so to speak) ... I read about potato diseases, but nothing fits ...
Good day!
Most likely, those few potato bushes, in which the leaves began to turn yellow, are early ripening. Potato bushes begin to decay 2-3 weeks before ripening. Perhaps, just when planting, you accidentally came across another variety of potatoes. You shouldn't panic and worry.
A neighbor gave 2 potatoes for divorce. The potatoes did not sprout for a long time. Then twisted sprouts appeared, like a fern in the spring. Again they unfold for a long time, but there are no leaves, but as if only veins. So far, everything is fine with my potatoes. Did I harm my landings? Thank.
Good day!
It is unlikely that you have done anything to harm your potato plantings. In this case, you need to wait a bit, what will happen next. Observe the new potato bushes for at least 2-3 weeks. And if possible, ask a few questions to the neighbor who shared the tubers with you. Find out what kind of potato it is, how it grows on her site, if there are any differences. You will always have time to dig it.
We wish you high yields!
Hello! Explain what kind of disease the potato has - the upper leaves begin to shrink, along the edge of their crimson color, and then the whole bush withers?
What is the reason, after flowering, the tops of the potatoes turn black, at first the leaf begins to turn black along the edge, then the tops turn black and dry with black dots, we treat them regularly with fungicides.?
Hello! Your potatoes are clearly struck by late blight. All nightshade crops suffer from this pathogenic fungus. You did not write what fungicides the culture was treated with - not all of them are capable of destroying phytophthora. In addition, even the "right" drugs will not always help - the fungus quickly adapts.
Copper fungicides work best with it. They will need to process not only plants, but also the soil after harvesting potatoes. In the spring, before planting, the procedure should be repeated - the spores live and winter in the ground.
Solanaceous crops cannot be planted in one place for two years in a row. You should not change their places, namely: plant potatoes where tomatoes, peppers or eggplants grew last year. There is only one pest in cultures, it will not go anywhere. Unfortunately, this does not always work.
If you have followed all the planting rules, it is possible that infected tubers were planted. The fungus could get on potatoes even when sick and healthy roots were lying side by side.
Phytophthora is so insidious that processing does not always give the desired result. So the drugs need to be changed.