The potato branch rots from the root. Potato tops wither: what to do. What is potato nematode

Sometimes potatoes give gardeners surprises in the form of rotten tubers in the spring, when their stocks are sorted out before planting. Rotten potatoes smell disgusting and cause nearby vegetables to rot. How to prevent spoilage of tubers and keep seed material intact? To answer this question, you need to understand the reasons for potato rotting.

Causes of rotting

How to deal with rot

Rules for storing potatoes

Conclusion

Causes of rotting

Why do potatoes rot immediately after harvesting, and why do they start to rot only towards the end of storage? The answer is simple - rot is caused by different types of infection.

Most often, the development of rot is caused by bacterial infections:

ring rot appears on potatoes when the first flowers appear.

The disease affects tubers, stems, leaves and stolons. When the tuber is cut, rot is visible, which is located around the circumference. The disease is widespread and destroys up to half the crop. Affected tubers can transmit the disease for several generations without symptoms.

A characteristic feature is a specific yellowish mucus that is released on the cut of wilted leaves; the plants grow dwarf. The disease spreads during harvesting through damage to the tuber skin.

Bacterial brown rot is a quarantine disease.

Potato brown rot destroys up to 70% of the crop in the countries where it is widespread. Since 2011, the pathogen has been detected on ware potatoes sourced from warm countries. The disease is still not widespread in Russian planting areas. Infection occurs through the root system.

The first sign is the sudden wilting of leaves, branches and the entire plant. The tuber's vascular ring turns brown and softens. During storage, the pulp turns into dark mucus.

wet rot turns the tubers into a gray mushy mucus during storage. The disease develops with excessive watering and dense soil.

Wet rot of potatoes spreads quickly when stored in a warm and humid room with insufficient ventilation.

pitting rot is most often discovered at the end of March. When peeling potatoes, small oily yellow spots are visible. Over time, the affected area expands and the peel bursts in these places;
fusarium develops especially actively in hot weather.

Fusarium, or dry rot, on potatoes manifests itself at any time, but especially often during the flowering period, causing the plant to wither. Infection is transmitted through the roots and from one tuber to another during storage.

Dry rot of potatoes affects tubers in the field, but the disease only appears during storage. First, grayish-brown folds appear on them, then the potato pulp becomes loose. And finally, the pulp dries out, cavities with fluffy mycelium appear inside. Fusarium disease of potatoes in storage is transmitted only to tubers with damaged skins.

A fungal disease in the form of rot is late blight, the most harmful and widespread.

Late blight can be identified by the appearance of brown, blurry spots on the upper leaves, which appear during the period when the tops close. The plant either dries out or rots depending on the weather. Tubers become infected during the growth period; the spots on them are gray-brown, slightly depressed, dense.

Without protective measures, late blight can destroy an entire potato field in 3 weeks. The crop rots during storage.

Important! The infection is not transmitted from one tuber to another.

In addition to the most common types of rot described above, pink, rubber, coal, white, stolon, wound, watery rot and fomoz can also be found.

How to deal with rot

It is impossible to instantly cure any potato disease. The source of infection is located both on the tubers and in the ground. Therefore, to prevent disease and eliminate infection, an integrated approach is always used:

pre-sowing treatment of tubers with protective agents;
dressing beds;
spraying tops;
processing of the harvested crop;
disinfection of storage areas;
constant monitoring of potatoes stored for storage.

Important! In the case of bacterial diseases best protection– This is prevention, since there are no complete measures to eradicate the infection.

You should plant only healthy seed material, destroy weeds, treat tubers before planting, observe crop rotation, and apply the optimal amount of fertilizer.

Gardeners knew how to deal with rot back in the days when chemical methods of protection were not invented. To suppress fungal microorganisms, leaves of plants that prevent the process of rotting were placed between the layers of potatoes: rowan, elderberry, wormwood, and sow.

Methods of control in our time have expanded through the use of chemicals. Before planting tubers or storing them, the following treatment is applied:

1% solution of Bordeaux mixture or copper sulfate;
Maxim KS;
Titus;
Aktofit;
Planriz;
Bitoxibacillin.

When wondering how to get rid of dry rot, we must remember that infection often begins when damaged tubers come into contact with wet soil. Therefore, potatoes should be harvested on dry and warm days, dried before storage, and damaged tubers should be discarded.

The number of manifestations of various infections when processing potatoes before storage with the microbiological preparation Fitosporin is significantly reduced.

Rules for storing potatoes

Before storing potatoes in the cellar to prevent them from rotting, the following preparatory work is carried out:

remove all remaining vegetables and fruits from last year;
the walls are whitened with slaked lime;
shelves and drawers are treated with a 2% solution of copper sulfate;
A mat treated with a 5% solution of copper sulfate is placed at the entrance.

The air temperature in the cellar gradually decreases with the onset of cold weather. But the optimal one should be kept at +13 °C in the first days. During winter, it should not fall below +2–3 °C with an air humidity of 80–85%. The freezing point of tubers occurs at –1.5° C; at 0° C, the starch in potatoes begins to convert into sugar and the taste of the vegetable becomes sweetish.

Important! You can use beets as a layer of thermal insulation, which better tolerates lower temperatures and protects potatoes from frost.

If an inspection of the stock reveals infected potatoes, you will have to sort through all the tubers and mechanically separate the damaged ones.

Conclusion

Knowing why harvested potatoes rot, you can and should try to prevent the infection from occurring during storage and get rid of it at the first sign of its appearance. Fortunately, the harsh climate of Russia does not allow many diseases to spread throughout the country. However, this does not negate the mandatory implementation of preventive measures.

Potato rotting is the result of exposure to pathogenic fungi or bacteria on the tubers. Mistakes made when planting, growing, harvesting and storing potatoes contribute to the rapid spread of diseases and loss of yield. However, with the help of simple preventive measures, it is possible to prevent massive rotting of tubers and reduce damage to a minimum.

The main diseases that cause potato rotting are:

late blight One of the most dangerous potato diseases. If you do not immediately destroy the first affected bushes, then within a few days the epidemic will cover the entire area. Tubers and tops of plants affected by late blight rot. The most effective way to combat the causative agent of the disease is to spray potato plantings with a 2% solution of Bordeaux mixture;
Alternaria blight (early dry spot - a disease that affects tops and tubers). The peel becomes covered with dark, shapeless spots, and the flesh gradually rots. Excessive soil moisture and lack of nitrogen fertilizers contribute to the occurrence of the disease. It is recommended to treat potato bushes with Bordeaux mixture, Integral or Bactofit preparations;
rhizoctoniasis (black scab). Indelible black tubercles appear on the surface of the tubers, then the peel cracks, the pulp underneath turns into dust;
fusarium (dry rot) is a disease that develops during storage of tubers. The potatoes rot, the pulp turns to mush and dries out;
phomosis (button rot) - during long-term storage, certain areas on the surface of the tuber turn into dry rot;
black leg - tubers turn into lumps of wet mucus;
ring rot - the tuber is surrounded by a wide yellow ring of rotten tissue. The disease is dangerous because an externally diseased tuber is almost impossible to distinguish from a healthy one. Rotten areas of pulp are visible only on the cut of the potato;
wet rot - penetrates into tubers through cuts, scratches or cracks in the skin that occur when potatoes are damaged various types scab.

Pre-planting preventive measures

Sick tubers either do not produce offspring at all, or weak, stunted plants sprout from them. Therefore, only healthy root crops are selected as planting material.

Planted potatoes often rot in moist clay soil. Therefore, it is better to plant whole potatoes in such soil, rather than cut tubers or eyes. If, however, planting is done in slices or eyes, the potatoes must be cut a few days before planting so that the open “wounds” are covered with a protective crust. Before cutting another tuber, the knife must be disinfected in a concentrated solution of potassium permanganate.

If the potatoes are not cut in advance and you have to do this immediately before planting, then each slice must be dipped in sifted ash: the substance has an antibacterial and disinfecting effect.

Ash is the best natural disinfectant

To protect the seed material from rot, the tubers are sprayed with a solution of copper sulfate, Bordeaux mixture or Maxim fungicide. To prevent potatoes from rotting due to damage to the skin by insect pests living in the soil, it is recommended to treat the planting material with the preparation before planting complex action"Prestige".

No matter how healthy the planted potatoes are, if there are pathogenic fungi and bacteria in the soil, some of the tubers may rot. To prevent crop loss, it is necessary to follow the rules of crop rotation: plant potatoes in one place no more than once every 3-4 years. In the vacated area, it is advisable to sow legumes, which saturate the soil with nitrogen. Exudations from the roots of winter rye, oats and white mustard have a depressing effect on pathogenic fungi and bacteria that cause potato rotting.

Prevention of rotting of tubers during bush growth

If, in the middle of a green potato field, the tops of several bushes begin to wither and the leaves turn yellow, this is a sure sign that the plants are affected by some kind of disease. You should immediately dig up diseased bushes and inspect the tubers. Withered tops and rotten tubers are burned; healthy ones can be eaten, but cannot be stored. It is necessary to understand why potatoes rot.

If the cause of decay is an infection, the bushes are sprayed with a drug intended to combat pathogens. But tubers can also rot due to lack of oxygen. To provide the potatoes with air access, the tubers are planted shallowly and, as necessary, the seedlings are covered with well-loosened soil.

Bordeaux mixture is a universal spraying agent, it is only important to apply it correctly according to the instructions

Another reason for potato rotting is unbalanced fertilizing with mineral fertilizers. Excess nitrogen in the soil can cause voids to form inside the potatoes, the pulp around which begins to rot. If in the fall it turns out that some of the tubers are rotting from the inside, it means that next year the amount of nitrogen fertilizers applied to the soil should be reduced, and potassium fertilizers should be increased.

Prevention of tuber rotting during harvest

Potatoes often rot in the ground after flowering, when late blight pathogens get onto the tubers from the fading tops. To prevent this and allow the potatoes to ripen properly, the tops are mowed 1–2 weeks before harvest.

When digging up potatoes, severely damaged or diseased tubers are immediately set aside separately: they cannot be stored for storage, otherwise the entire crop may rot. The remaining potatoes are kept in a dark, well-ventilated place for 1–3 weeks so that all scratches heal.

Tubers with mechanical damage cannot be stored

Protecting potatoes from rotting in storage

Pathogenic fungi continue to live in storage even after all the potatoes are removed from there. Therefore, before storing new harvest potatoes, the cellar is whitened with lime with the addition of copper sulfate, and all shelves and drawers are disinfected with a solution of potassium permanganate. To get rid of mold, it is also recommended to use special smoke bombs.

Practice shows that the worst preservation is:

potatoes dug up during prolonged rains;
early varieties of potatoes.

To protect against rotting, tubers are treated with a fungicide before storing them in storage. Previously, the drug "Maxim" was used, but due to its toxicity this drug must be used carefully. Modern bacterial preparations “Fitosporin” and “Anti-Rot”, which are safe for human health, very effectively prevent potato rotting.

The potatoes are carefully sorted and placed in boxes. For additional protection against fungi and bacteria (especially when the crop is stored indoors), layers of potatoes are interspersed with rowan, fern or wormwood leaves. If in winter a rotten potato is found in a box, the spoiled tuber is thrown away, and the neighboring ones, even if they are apparently healthy, are primarily used for food or pet food.

To prevent the tubers from rotting from lack of oxygen, ventilation should be installed in the cellar. The ideal temperature at which pathogenic microorganisms do not develop is from +2 to +4 °C. In the spring, when it warms up, it is recommended to freeze several 5-liter plastic bottles of water in the freezer and place them in the cellar: the ice will slowly melt, cooling the room.

Vegetables on top of potato tubers absorb moisture well

Excess moisture also causes potatoes to rot. If droplets of water settle on the ceiling in the cellar, it is recommended to lay 1-2 rows of beets on top of the potatoes, which will absorb excess moisture condensing on the tubers. Another option for drying air in very damp cellars is to install a container with quicklime in the corner.

Some gardeners, in order to avoid crop losses from potato plants, plant innovative technologies in barrels, bags and under hay. But they soon become convinced that this does not save the tubers from bacteria, fungi and viruses that provoke a variety of ailments. They mercilessly attack healthy plants and their fruits in the open ground, and even in the cellar. Others often act as carriers of pathogens. Let's take a closer look at what potato diseases there are and measures to combat them.

Important! It is almost impossible to instantly cure planted tubers from diseases of any nature. This is due to the fact that most pathogens infect soil or seed. As a result, the fight against them should begin with processing and treating the fruits, as well as carefully preparing the bed for planting.

Bacterial diseases of potatoes

Bacterial diseases of potatoes are provoked by various kinds of microbes, which gradually spread from the tubers along the stems, infecting everything. It is extremely difficult to fight them, since the soil in which the root crop grows also needs disinfection.

To cope with such a task, timely and competent sowing changes are necessary. Sometimes this will take years with alternate sowing of microorganism-resistant crops, such as wheat, corn, barley, in the infected area.

Brown bacterial rot

The disease occurs due to the activity of microorganisms Ralstonia solanacearum on potatoes. Its first manifestations are noticeable during the flowering period of the crop, when root crops begin to form. At this time, yellowing and wilting of the foliage is observed, it becomes wrinkled and lifeless, and the stems droop down and turn brown over time.

As pathogenic bacteria multiply, softening and putrefactive processes are observed in the lower root part of the stem. Splitting is clearly visible along the sprouts, and the infected veins acquire a brown, putrid color.

If you cut the stem of a diseased plant, you can see dark fibers on the cut ring. Brown. When such a sprout is squeezed, a gray-white cloudy mucus will be released from it.

Botanists classify brown rot as a vascular disease of potato and note the death of bushes as a result of clogging of xylem veins with a dense gumy mass. There are cases when the disease manifests itself only as verticillium wilt and ring rot, in which there is no splitting of the shoots and mucous discharge is observed.

The disease on tubers is expressed by a softened vascular ring and the appearance of brown putrefactive elements on the core. Often, decay processes begin already in storage facilities. They are accompanied by mucous discharge and an unpleasant odor. Such potatoes infect all neighboring tubers and completely rot.

Did you know? According to the International Finance Corporation, Ukrainians annually consume about 4 million tons of potatoes, despite the fact that the average annual yield of root crops is approximately 18 -19 million tons.

The country's leading agronomists draw the attention of farmers and landowners to the fact that the fight against bacterial diseases of potatoes should be aimed at comprehensive protection against the pathogens described above. At the heart of all such measures is the management of relations between internal and external populations.

This means that the plant must be protected throughout the entire growing period using different methods, including seed production and organizational and economic nuances, as well as the principles of combining crops.

When brown rot appears, crop rotation and the application of optimal fertilizers are key in the fight against it. It will be possible to plant potatoes on infected soil only after 5 years. Seed tubers must be carefully sorted and heated for 20 to 30 days. This will help to accurately detect unsuitable material. It will also be indicated by a 0.002% solution of succinic acid, which is used to treat the fruits for half an hour.

If during planting it becomes necessary to cut root crops, use a knife to mandatory need to be disinfected with formaldehyde or potassium permanganate. Healthy, for preventive purposes, before planting, they are treated with chemicals such as: “TMTD”, “Rizoplan”, “Baktofit”, “Polycarbocin”, repeating the treatment twice on seedlings until budding begins.

Varieties with increased resistance to microbes are well cultivated: “Resource”, “Ulyanovsky”, “Udacha”, “”. Control of bacterial diseases of potatoes includes regular inspection and removal of diseased plants.

Experts advise carrying out the first cleaning after the stems reach a height of 25 centimeters, the second during flowering, and the third several weeks before harvest. It is important to completely mow the tops during this period so that they have time to dry before harvesting the fruits. The entire crop should be thoroughly dried before storing in the cellar. Preparatory work is also needed in the storage facility.

For this purpose, remove all the remaining last year's and, disinfect with a 2% aqueous solution and treat the walls with extinguished. When entering the room, place a mat soaked in a 5% solution of copper sulfate.

Important! To safely preserve potato tubers in the cellar, for the first 20 days the room temperature should not be lower than +13 °C, and the air humidity should be kept at 90%. In the future, gradual cooling to 2 degrees is necessary.

Ring rot

Signs ring rot quite noticeable on potato tubers and biomass. They appear after flowering in the form of yellowing of thin shoots and curling of leaves. Affected specimens are difficult to pull out, even with general cell death. This happens due to the destruction of the stringy structure of roots and shoots.

The disease begins from the roots, but its first symptoms can be noticed on the fruits only when they are cut. Yellow or brown rings on the edges of the core indicate the further development of putrefactive processes that will eventually destroy the entire fruit. When pressed, gray-yellow mucus flows from the affected areas.

If, when examining the seeds, you did not notice signs of rot and planted such a root crop, dwarf, poorly developed, thin shoots with small deformed leaves will grow from it. You should not expect a large harvest from such bushes.

In most cases, bacterial diseases arise due to poor-quality planting material, or due to mechanical damage during harvesting root crops, transporting tubers in contaminated containers, as well as when storage rules are violated. Today there are no special pesticides against putrefactive diseases of nightshade crops.

They are fought with quarantine methods, which, in addition to proper preparation of planting material and harvesting, include sowing changes for 3 years, selection of resistant varieties, potato fields with potassium preparations and systematic removal of diseased plants at the first signs of rot.

Did you know? Potato diseases destroy from 30 to 65% of the crop.

Wet rot

The disease begins at the core of the tubers and, often, at initial stages development is difficult to determine. Its root cause is bacteria or fungal pathogens that enter the root crop due to mechanical damage or are carried by pests. Based on these factors, it becomes clear why potatoes quickly rot from the inside.

This process is expressed in the softening of the tubers and the spread of a strong stench. Rotten tissues are initially white, but later they turn brown, acquiring darker shades. By the way, the skin is affected when the inside is completely rotten. It happens that the surface of root vegetables becomes covered with dark dents, from which, when squeezed, a whitish starchy substance flows out.

If a root crop is exposed to cold conditions, its eyelids die and the process of rotting begins. Therefore, such tubers should not be protected; it is better to use them immediately, otherwise they will ruin the entire harvest. Farmers note that very often potatoes are affected by this disease in the cellar, especially when the product freezes or, conversely, is piled in a compartment and stored at temperatures above +4°C.

Appearance wet rot also accompanied by high indoor humidity and poor ventilation. This is explained by a lack of oxygen, which entails a decrease in the immunity of potato fruits. You can, again, get rid of the problem through comprehensive measures. To do this, it is important to ensure that the soil in which the crop grows is not waterlogged and is well loosened. When storing in storage, select healthy tubers and dry them thoroughly.

It is advisable to treat seed potatoes with the chemical “Maxim” before placing them in the cellar. And also protect the crop from various kinds of abrasions and cuts, take timely measures to combat pests. For the winter, place root vegetables, regardless of their purpose, in boxes or vegetable nets. In cases where you find foci of putrefaction, remove all tubers from the infected area and try to use them as soon as possible. Also strictly follow the rules for storing potatoes (we mentioned them above).

Did you know? Every year, Europeans collect about 35 tons of potatoes from 1 hectare, while Ukrainians collect only 15 tons. This difference arises as a result of the fact that 95% of the product is cultivated in small farms, which, of course, affects the quality of the tubers.

Mixed internal rot

This disease of potato tubers, like previous types of bacteriosis, occurs when root crops are wintered improperly and as a result of mechanical abrasions, blows, and cuts. Symptoms depend on the type of pathogens that have entered the tissue membranes of tubers. You can observe the signs of wet or ring rot, as well as dry rot, that we have already described. A gray, pink or brown slippery coating will certainly appear on the affected areas.

The methods of combating these microbes are no different from those mentioned above. Your main task is to protect the crop from mechanical damage, to ensure the right conditions to save it. It is important to disinfect seed material before planting with any antibacterial and antifungal chemicals. Experienced summer residents recommend the drugs “Fludioxonil” and “Maxim”.

Blackleg

The disease begins to manifest itself as soon as favorable conditions arrive: increased dampness or prolonged hot weather. During drought, the course of the disease is sluggish and becomes chronic. The black leg is noticeable on both the underground and above-ground parts of the potato: the stem below turns black, the leaves turn yellow, the bush gradually fades, and the root crops begin to rot.

In the heat, within a week, the sprouts will begin to soften in the root zone, which usually fall due to their own weight. Infected specimens are easily pulled out, and mucous discharge is visible on stem sections. Tubers rot from the stolon areas, becoming covered with dark spots. A sure sign of the disease are putrefactive spots on the potatoes, darkened skin, cracks from which a stinking, pulling liquid is released. Such root vegetables are very light, which indicates the complete destruction of their insides by bacteria.

Blackleg can be overcome by strictly following the rules of agricultural technology for growing potatoes, harvesting and storing them. In this aspect, crop rotation, planting high-quality seeds, timely loosening of the soil, phyto-cleaning and weed elimination, and disinfection of work equipment are important. Before planting, it is advisable to treat the tubers with preparations such as: “Maxim”, “Prestige”, “TMTD”.

Important! In order for seed potatoes to be well preserved until spring, they need to be greened in the fall.

Fungal diseases of potatoes

Botanists describe this group of potato diseases as the most serious and dangerous. The appearance of various fungi on the bushes or in the roots of potatoes necessarily entails disease.

They are often carried by harmful insects or caused by improper conditions for cultivating root crops. Let's consider brief characteristics the most common fungal diseases and methods of combating them.

Common scab

The disease appears as a result of the activity of radiant fungi of the genus Streptomycetes. The precursors to their occurrence are low level, limestone, sandy, sandy loam substrates and hot weather conditions. The pathogen enters the tubers through the stem. Infected fruits lose their taste and presentation. Small brown asymmetrical spots appear on the potatoes, which “cork” over time.

As they develop, the sores merge together, and a coating is barely noticeable on freshly dug fruits. In the sun it quickly dries out and loses its mark. The core of such root vegetables, despite the ulcerative crust formed on the outside, does not change. For preventive and therapeutic measures, Candidate of Biological Sciences, Professor of NUBiP of Ukraine Ivan Markov advises observing crop rotation and rules for fertilizing potatoes.

According to the scientist, fresh, overdose and contribute to the development of pathogens. Therefore, it is important to introduce physiologically acidic substances at the rate of 60 kg per 1 ha, which are manganese sulfate and ammonium sulfate. Nitrogen stabilizers are also desirable.

The harmfulness of scab is significantly reduced with proper dosage of calcium chloride, manganese, boron, copper, and cobalt. Calculate the required number of listed chemical substances for a specific field can be based on its agrochemical examination, which can only be done by a specialist.

If there is no possibility or means for laboratory tests, you can use the cheapest way to combat scab, focusing on disease-resistant potato varieties. Do not be afraid of fungal diseases “Bozhedar”, “Kosen 95”, “Chernigovskaya 98”, “Lugovskaya”, “Borodyanskaya pink”, “Vesta”, “Symphony”, “Vodograi”, “Velox”, “Gatchinskaya”, “Volovetskaya” ", "Zarevo", "Lybid", "Drevlyanka", "Serpanok", "Poran", "Rozara" and other varieties with thin skin of reddish tones.

Also, each owner of a land plot should take care of the condition. To enrich it with useful elements, it makes sense to organize the plowing of green manure: lupine, clover or. Before burying, high-quality root crops selected for planting are treated with the preparations “Maxim”, “” and the growth regulator “Agat-25K”. After buds begin to form on the seedlings, the soil must be irrigated for 4 weeks, maintaining humidity at 75%.

Powdery scab

You can save potatoes from slime mold by regular sowing changes, planting high-quality seed, which should first be treated with fungicides (Maxim). The collection of root crops should be organized in dry, warm weather, observing the above rules for harvesting and storing tubers. In heavily contaminated areas, re-cultivation of the plant is possible only after 7 years.

Did you know? According to the Main State Plant Protection Inspectorate of Ukraine, in 1996 all potato plantings in household plots and agricultural enterprises in the Lviv region were affected by scab. This was a burst of intense fungal development. The latest data on tuber infestation is 17 – 24%.

Silver scab

By spring, they will show clear dents and a silvery sheen, which occurs as a result of complex processes of tissue exfoliation and access of oxygen to the formed cavities. In cases where mass infection occurs, the upper shells of the fruit are severely deformed, losing moisture.

Comfortable conditions for the development of silver scab on potatoes are dampness in the storage and too much heat. For example, 1 hour at +15 °C is enough for the formation of pathogenic spores. At +3 °C, mushrooms are not produced.

Methods of combating silver scab are traditional, as in previous cases bacterial and fungal diseases. They differ only in the means for disinfecting seed potatoes. Agronomists advise using the following drugs: “Vivatak 200”, “”, “Maxim”, “Bontan”, “Titusim”, “Nitrafen”, “Tekto 45”. Dressing should be carried out immediately after harvesting root crops.

Black scab (rhizoctoniosis)

Compared to silver and common scab, rhizoctonia affects not only tubers, but the entire plant. The disease appears from substrates infected with pathogens, especially in the cold season. This distinguishes black scab from other species and poses a great threat to tubers planted in unheated soil.

Young shoots of diseased crops are very sparse and depressed. Black, warty dots are noticeable on root vegetables, which peel off easily and can merge together.

On the stems, the disease manifests itself as brown sores, which in the root part are covered with a felt-like whitish coating, and on the roots - with rough spots. The massive spread of fungal spores can significantly reduce the yield and completely destroy it in the cellar.

Its development is favored by cold and dampness. Therefore, for prevention, do not rush to plant potatoes, give the soil a chance to heat up and lose excess moisture. Take a good look at the seed roots, discarding contaminated samples.

Before planting, it is important to treat healthy tubers with Fundazol, Prestige or Maxim. Timely rotation of crops in the garden, elimination of tops before harvesting and plant residues after harvest, and fertilizing the soil exclusively with rotted organic matter are also important.

Important! To increase productivity, potatoes should be renewed every 4 years, giving preference to elite, uninfected varieties of Dutch selection.

It is also important to germinate seed tubers in the sun, since sprouts that appear in the dark are the first to be affected by black scab. Agrochemists advise treating diseased bushes with potent drugs: Ditan M-45, Colfugo, Mancozeb, Fenoram Super.

Important! To save healthy potatoes from the scourge of black scab, it is recommended to organize early harvesting of the fruit.

Alternaria (dry spotting)

Alternaria potato blight is caused by fungi of the genus Alternaria, which become more active in dry and hot weather. You can notice traces of their vital activity starting from the flowering period of the plant. Symptoms are clearly expressed until the root crops are harvested. The disease manifests itself on leaves and sprouts; rarely, fungi infect tubers. You should be alerted by brown round or triangular spots that appear on the foliage or stems.

Myceliums are easily transported by the wind, infecting new areas of the garden. This is the danger of Alternaria leaf disease on potato leaves. The fact of focal spraying of spores becomes clear. Their formation is facilitated by frequent changes in damp and dry weather, lack of moisture, unfavorable soil conditions, lack of potassium and nitrogen, and excess phosphorus.

Young fruits become infected with the fungus when they come into contact with the soil when dug up, while mature fruits become infected in the presence of abrasions and other mechanical damage. To destroy the fungi that cause dry spotting, the first step is to eliminate the primary sources in the soil. This is done by autumn plowing. In the future, beds with potatoes should be placed as far as possible from tomatoes, since Alternaria blight is dangerous for all nightshades.

Seed tubers should be carefully examined, discarding specimens with a black or brown surface and slightly concave spots with uneven but clear edges. It is important to fertilize grown seedlings on time. As soon as you notice the first signs of the disease, immediately spray the planting with any fungicide. It is advisable to re-treat depending on the degree of infection and the long-term effect of the drug used.

It is better to carry out disinfection in cool and damp, possibly rainy, weather. The percentage of the harvest you save depends on following the harvesting rules and storing it in the cellar. We have already mentioned above how to do this correctly.

Some summer residents share their experience of planting varieties resistant to Alternaria. For example: “Lina”, “Nevskaya”, “Victory”, “Fairy Tale”, “Reserve”, “Lyubava”, “Skoroplodnaya”, “Volzhanka”, “Master”.

Did you know? Spanish farmers flatly refused to cultivate potatoes only because the root crops frightened superstitions with their human-like shapes.

Potato cancer

This is a fungal quarantine disease provoked by microbes, due to the activity of which damaged tubers are prohibited from being transported from their places of growth. Pathogenic microorganisms spread to root crops and the root system of the plant. The cancer appears as growths with a wavy structure that resembles cauliflower.

Over time, these formations increase in size, change color, and move to the root zone of the stems and stems. At the final stage of development, they become black with a slippery, putrefactive surface. The spores are easily transferred to healthy fruits, especially during times of high soil moisture. They get into the ground with the help of working equipment, animals and manure, and remain viable for 4 years.

To get rid of the problem, pour kerosene, bleach or formaldehyde on infected fruits and tops and bury them to a depth of at least 1 meter. As an alternative, some gardeners suggest burning all affected plants, although surviving potatoes are not suitable for seed, as they are a potential carrier of pathogens. It is better to use such tubers for food purposes.

Of course, the purchase of seed material is carried out exclusively in specialized centers. Before planting, inspect the tubers - cancerous spores may be hiding under the soil stuck to their surface. Organic and mineral fertilizers help free soils from infectious microbes. But it is important to ensure that the manure is thoroughly rotted. Chemical methods of combating cancer are only available under the supervision of a plant quarantine inspector.

Important!Tubers that have grown in cancer-affected areas can be disinfected before sowing using a 1% Fundazol suspension.

Dry rot (fusarium)

The reasons why dry rot appears on potatoes are considered to be gross errors in agricultural technology and unfavorable soils, as well as mechanical damage and improper storage of tubers in winter. The symptoms of the disease clearly appear on the tubers in the form of dark swamp-brown spots, which over time transform into shallow dents. The skin on the affected areas is wrinkled, and a pubescent coating is noticeable. A similar picture occurs inside the fruit.

With the development of fusarium, the bushes of the plant begin to wither, droop the stems and lose viability. If you cut off a diseased sprout, you can see a dark ring where the blade passes.

In order to destroy pathogenic dry rot fungi, it is recommended to strictly follow the rules of agricultural technology and storage of the harvested crop, plant only high-quality material, protect potatoes from blows and cuts when harvesting, and annually carry out pre-sowing treatment of tubers with fungicidal preparations (for example, “Maxim”, “Prestige”).

Late blight

A fungal potato disease called late blight is considered the most insidious of the entire list of ailments. It affects the entire plant, but appears primarily on the foliage during budding of the bushes. You can recognize the appearance of late blight by the brown felt spots that form on the underside of the leaves and, growing, cover the plant with a solid brown carpet with a light white coating. On the stems, the disease is revealed by long dark stripes. Such a plant is not able to fully develop; rotting processes begin in it.

Favorable conditions for the occurrence of late blight are high humidity after prolonged rains, warm weather and lack of good ventilation. When the weather returns and the soil dries out, the mushrooms stop functioning. But this does not mean your victory over the disease, since after the first rain the disease will begin to progress.

To cure a crop, in addition to traditional methods, proper cultivation and storage of root crops, be sure to spray the bushes with a boron mixture, “Oxychom” or “Polychom” at the initial signs of late blight. Some summer residents resort to folk technologies for prevention, treating the foliage with garlic tincture six times. This process begins at the beginning of flowering and is repeated every 14 days.

The preparation of seed material is also important. In addition to germination and discarding everything unsuitable, the tubers should be treated with “Fitosprorin”, boric acid or copper sulfate. The soil in contaminated areas in spring and autumn is also treated with the above-mentioned preparations.

Did you know? In the 17th century, the French introduced the fashion of decorating costumes and wigs with bouquets of potato flowers. In this country, the plant has long been cultivated as an ornamental.

Potato blight

Phoma pathogens penetrate the root crops, stems and sides of potatoes, having a detrimental effect on them. The sore appears as elongated, shapeless spots covered with brown dots.

As they develop, fungal spores ring the shoots and prevent the culture from developing. Affected bushes differ from healthy ones by loss of foliage color saturation and lifelessness. If no measures are taken, the plant will die. On tubers, signs of phomosis are expressed in the form of ulcers that spread up to 6 cm. Over time, deep cavities appear in the affected areas. Such specimens stored in the cellar contribute to the proliferation of mycelium. They are also accompanied by post-harvest residues and weeds abandoned in the garden.

Viral diseases of potatoes

Dangerous pathogens of potato viral diseases cause damage to yields gradually, resembling a time bomb. In the first years, their vital activity is almost unnoticeable, but later they destroy up to 50% of the fruits. Carriers of such diseases are Colorado potato beetles, aphids, cicadas and other pests. Infection during processing of root crops is also possible. Let's look at the most common potato diseases caused by viruses.

Ordinary mosaic

It is caused by several viruses at the same time. Favorable conditions for this are mechanical processing and the presence of harmful insects in the garden bed. Appears on young leaves as barely noticeable light green dots of asymmetrical shape. Over time, this mottling darkens and spreads to the entire bush.

Wrinkled mosaic

When infected, the leaf tissues of the plant swell greatly, forming peculiar folds. They arise as a result of poor outflow of assimilated products. 3 years after cultivating infected potatoes, you will notice how the plants degenerate into dwarf plants with corrugated, underdeveloped foliage and very fragile stems. Such a bush is not able to set buds and bear fruit. He will finish his own a month earlier than healthy specimens.

Striped mosaic

For banded, the characteristic features are mosaic specks, which, first of all, appear on the lower and middle leaf blades. Later, black stripes and veins form on the affected areas. The leaves break easily, die quickly, and often hang lifelessly, exposing the stem before budding begins. The pathogen overwinters in root crops.

Gothic potato tubers

The disease occurs through the ingestion of the spindle veroid virus (VVVV), which is why it is also called “spinoid virus.” The harmful microbe manifests itself by deforming the tubers, deteriorating them taste qualities and presentation. The foliage of diseased bushes is too elongated, very small, and does not develop properly. The edges of these leaves have an anthocyanin tint. Diseased plants grow poorly, are stunted, and the color of the tubers of red-skinned varieties is lost. At the same time, the root crops grow small in size with a spindle-shaped shape.

Did you know? The most dangerous and widespread viruses are the PLPV and PVY viruses, which reduce the weight, quantity and starchiness of tubers, killing up to 80% of the crop.

Necrosis of potato tubers

The development of necrosis on potatoes begins with the entry of the Tobacco rattle virus into the soil and tubers, which reduces the starch content and leads to necrosis of the fruit. Characteristic Features diseases are considered small light specks that cover the leaves, deformation of inflorescences, dark necrotic spots on root crops, which often bend into bizarre stripes, arcs or rings.

A very high prevalence of this virus is observed in sandy and swampy areas. Today there is no drug for viral potato diseases that would immediately solve the problem. However, in order not to lose the entire harvest, if symptoms of any of the listed viral infections are detected, immediately organize phytocleaning, repeating it periodically until all affected plants are removed.

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Getting a decent harvest of healthy potatoes is the goal of every summer resident. But often plant diseases destroy all our plans and expectations. There are plenty of diseases in potatoes. Dealing with them and carrying out proper processing is the main task for a successful worker. High-quality prevention and timely treatment will save and give you a bucket of potatoes from each bush.

Potato late blight, brown rot

Losses from this disease occur up to 70% during outbreak years, with a relatively prosperous season up to 15%. Late blight is the most insidious and dangerous disease of nightshades.

How to distinguish and recognize?

The causative agent is a lower fungus oomycete. The incubation stage lasts from 3 to 15 days, so the first signs of damage appear very quickly. Zoospores are preserved in soil and seed. With wind and rain they are spread throughout the potato field. Along the growing stems they rise into the tops and descend into the tubers with moisture. Conditions for progressive infection:

temperature 20 degrees;
humidity 90%.

The main manifestations of brown rot:

there are brown spots on the leaves that quickly spread throughout the bush;
on the reverse side of the sheet - white coating, containing spores;
a little later the leaves completely darken, curl and dry out;
the tubers are covered with lead-gray depressed seals;
stains penetrate far into the depths in the form of smudges.

Disease prevention, top 12 rules

Prevention comes down to the following tips:

Choose soil that is light, non-clayey, drained and level.
The area is illuminated and ventilated.
The varieties are resistant and strong.
The tubers are healthy.
Landing early.
Harvest in dry weather.
Crop rotations every three years.
Dry the tubers well for storage.
Sowing green manure for the winter is mandatory - mustard, radish, oats, wheat.
In early spring they are buried in the ground to rot.
Fertilizing the land with phosphorus and potassium preparations.
Treatment of tubers before planting with fungicides - Agat-25K, Immunocytofat.

Important! When doing the autumn sorting of tubers, the diseased ones must only be burned.

Breeders are constantly developing new varieties that are resistant to the pathogen. Here are the most popular ones:

Arina;
Verb;
Rosara;
Sante;
Lazarus;
Visa;
Oredezhsky;

This does not mean that these representatives will not become infected with the fungus. But their disease will occur in the mildest form.

Treatment

Late blight cannot be cured, but it is imperative to fight to contain it. The first spraying is carried out at a tops height of 25 cm. For this, Bordeaux mixture, copper sulfate, copper sulfate, and manganese solution are widely used. When there is a risk of late blight, special means are used to treat plants:

Epin, treated before flowering;
drugs that increase the plant's defenses: Silk, Krezacin, Immunocytophat;
contact antifungal agents – Efal, Ditan, copper oxychloride;
Ridomild Gold MC, Ridomil MC, Oksikhom. These fungicides are sprayed during the height of the disease. But only before flowering;
Bravo, Alufit, good to use after flowering.

Potato cancer

If there is 1 pathogen cyst in 1 g of soil, 10% of the potatoes will die. 25 sporangia will kill 60% of the crop.

Who causes the disease, the cunning of the pathogen

temperature +15;
humidity 90%.

The pathogen moves through the capillaries of the soil. He has 12 hours to implement. Once in plant cells, it produces toxins. These substances cause rapid growth of neighboring cells - a tumor-like formation is formed in the form of a growth.

Sources of infection:

the owner himself - his shoes and clothes;
contaminated garden supplies;
humus from animals that have eaten contaminated potatoes;
soil worms;
garden pests;
diseased plants.

Manifestations of the disease

Symptoms of cancer are specific and difficult to confuse with something else. Main features:

tubers are affected, less often stolons and stems;
tubercles grow on potatoes near the eyes;
growths form from the tubercles.

There are three types of cancer:

Leaf-shaped. The growths look like leaves.

Scabby. There are many small growths on the peel.

Corrugated. The surface is lumpy and wrinkled,

Prevention measures

To prevent the disease you need:

Carry out crop rotation every three years.
Plant tomatoes and peppers further away.
Purchase planting tubers from trusted nurseries.
If there are cancer outbreaks nearby, purchase resistant varieties.

Important! Experts suggest that diseased potatoes pose a threat to human health. Its tubers cannot be used for food.

Resistant varieties:

early - Forget-me-not, Spring, Anosta, Aksu;
medium - Condor, Nevsky, Sante, Andretta;
later – Cardinal, Lasunak.

Treatment

Fighting cancer with fungicides:

A 0.5% Benomyl solution is used to disinfect planting material. To do this, seeds and tubers are dipped into the solution for 30 minutes.
Tubers are treated with 1% Fundazole for half an hour before planting.
To destroy the fungus in the soil, use a 2% Nitrofen solution. For 1m2 20 l. Nothing can be planted in this area for 3 years.

Potato Alternaria

The disease is caused by fungi - Alternaria alternata and Alternaria solani. Crop losses range from 10% to 50%. Optimal conditions for pathogens are temperature -25-30 degrees, drip irrigation for less than 2 hours.

Factors contributing to the occurrence of the disease:

heat, lack of watering;
low potato resistance;
imbalance of soil minerals - lack of nitrogen and potassium, high concentration of phosphorus;
contamination of seed material with any viruses.

How to recognize Alternaria?

The disease affects the middle and late varieties. Signs appear two weeks before flowering. Alternaria symptoms:

brown dry spots on leaves up to 3 cm;
round shape, there are spherical rings;
the disease begins from below and rises upward;
leaves are affected from the center to the periphery;
after 20 days, a plaque with spores appears on the spots;
with the stems everything happens exactly the same;
deep spots appear on tubers.

Control measures

Treatment is carried out when symptoms are identified, as quickly as possible. Primary spraying is carried out when the tops begin to close. The decision to carry out the following depends on the course of the disease. No more than 4 treatments are done per season. Chemicals are used for spraying. Their use is regulated by the manufacturer. This:

Metamil;
Ordan;
Bravo;
Folman;
Profit;
Acrobat;
Mancozeb;
Cuproxat.

Prevention

To prevent Alternaria you need to:

Destruction of contaminated potato residues.
Deep autumn plowing.
Perform crop rotation every 3 years.
Use resistant varieties: Master, Reserve, Pobeda, Golubizna, Resurs.
Soak the seed material in biological preparations – Agat-25, Baktofit, Integral.
Discard diseased tubers in a timely manner.

Fomoz, button rot

The disease is one of the most dangerous and formidable of all potato pathologies. This disease has many names - gangrene, phomosa and button rot. Huge damage is caused to potatoes during Phoma. The tops rot and die, the tubers do not ripen. If the winds blow and it rains, the disease becomes epidemic. Up to 25% of the potato crop rots in storage.

An imperfect strain of fungal pathogens belongs to the genus Foma. Different strains of pathogens infect the stems and root system. Disputes hide in special education pycnidia formed on the tuber skin. Favorable conditions for damage are:

cold;
high humidity.

The method of distribution is airborne.

How does Phomasis manifest itself?

The first signs of infection are visible during the growing season. Damage to tubers is determined when digging up the crop. During storage, Phoma continues to progress, until April the potatoes completely rot.

Main symptoms:

dark elongated spots appear at the base of the petioles;
they surround the stem in a ring-like manner;
upon careful examination, brown pycnidia are visible;
infected stems quickly rot;
the infection enters the soil and tubers through eyes and wounds on the skin;
The stolons become infected, and through them all the potatoes.

The ocellated form of Phomosis is distinguished. The pathogen is introduced through the eyes. Putrid dents quickly form. Potatoes are dying en masse.

There is another form of gangrene - necrosis of the epidermis. Shallow ulcers, no more than 5 mm, are noticeable on the peel. They may completely cover the peel or partially. The color of the affected tissue varies from pink, yellow to brown.

The disease has 3 stages:

Initial. Circles appear on the tubers, similar to the hole left by a button. Hence the name - button rot. When cut, diseased tissue is separated by a strip, contains spores, and is brown in color.
The height of the disease. Cavities appear in the tubers, covered with a layer of fungal mycelium. Diseased tissues turn black.
Final. The tubers dry out, leaving dead tissue and pycnidia inside.

Prevention

Crop rotation every three years.
Two weeks before digging up the tubers, mow the tops.
They prepare the storage area - whitewash the walls with lime, spray all surfaces with disinfectants.
Choose stable and high-quality seed material.
The tubers are treated with Maxim 025FS before planting. 8g of the drug is needed for 20 kg of tubers.

Treatment with fungicides

The first treatment is carried out during the growing season. Used by Thanos, Shirlan.
Second spraying before flowering. Use Unomil, Ridomil GoldMC.

Potato scab

The disease is a fungal disease. The pathogen primarily affects tubers and stolons. Potatoes become tasteless and lose 30% of their starch. Experts distinguish 4 types of disease:

Ordinary;
Powdery;
Silver;
Black – rhizoctoniosis.

Common scab

Pathogens persist in tubers, soil, and potato residues. They prefer alkaline, dry soil. Penetrate through cracks in the skin. Potatoes keep well.

Manifestations - ulcers different shapes cover the tuber skin, there are cracks.

Powdery scab

The most common type of disease. The pathogen looks like a piece of mucus that moves slowly. Tubers and stolons are sick. Potatoes don't store well - they rot quickly. The source of infection can be contaminated soil, tubers, or manure from animals eating diseased potatoes. The development of scab is promoted by heavy soil, plenty of moisture, and warmth up to 18 degrees.

Main features:

Silver scab

Plants grown on sandy loam and loam are affected. Optimal conditions are humidity 90%, temperature about 20 degrees. Affected potatoes are stored well, do not rot, and only dry out slightly.

Signs by which pathology can be distinguished:

potato skin looks wrinkled;
the color of the spots is similar to silver paint;
during storage, stains may darken, turn brown, or press in;
Under the shell, when cut, black formations are visible.

Black scab

It is considered one of the most dangerous fungal diseases. Occurs at any stage of development. Optimal conditions are high humidity and warmth. If the spring is cold and damp, the bushes die en masse. Harvest losses reach up to 25%.

What are the main symptoms that help recognize rhizoctoniasis?

Black spots on potatoes.
They do not wash off, are not torn off or scraped off.
The stems are low and quickly wither in the sun.
The leaves are curled.
A white leg appears on the stem.

Measures to combat scab

Potato scab requires a number of measures to get rid of it for a long time. Need to:

Choose resistant varieties.
Select healthy planting material
Store in a dry and ventilated area.
Treat seed potatoes with TMDT and polycarbacin before planting.
Sprout tubers in the light.
Carry out crop rotation.
Plant green manure in winter - mustard, oats, rye.
Treat alkaline soil with ammonium sulfate - 2 tbsp. for 10 liters of liquid.

Fusarium wilt

The disease is caused by the fungus Fusarium sporotrichiodis. The pathogen penetrates from the root system and infects stems with leaves. Potatoes die massively and quickly within 3 days. The loss of potatoes during infection outbreaks is 40-50%. The height of the disease occurs during the flowering period.

Main symptoms:

yellowing and wilting of leaves, despite regular watering;
twisting of the leaf blade longitudinally along the vein;
the bottom of the stems is covered with a multi-colored coating. Pathogenic spores are stored here;
the potatoes die quickly.

Fusarium or dry rot

This is the name given to the defeat of potatoes laid for storage. After two months they appear characteristic features. The peel wrinkles and brown indentations are visible on it. The disease penetrates through the tubers - the mycelium completely replaces the starchy contents. You can see pads with condium and mycelium. attractive Pink colour. Losses of stored potatoes amount to 20%.

How to prevent it?

Control measures are effective prevention.

3 weeks solarization of seed material.
Carry out pre-planting treatment - boric acid, copper sulfate.
Treat the tubers with Maxim and Colfugo Super Color.
Apply potash fertilizers in the fall.
Limit nitrogen fertilizing.
Treat the walls of the storage facility with lime and 5% vitriol.
Before storage, carry out special treatment. Keep the potatoes in a dry, ventilated area at 17 degrees for 7 days.
Ventilate the storage area.

Potato powdery mildew

The pathogen is a marsupial fungus. The disease occurs in warm latitudes.

How to identify and recognize?

The spores spend the winter well in soil and potato residues. The disease begins after flowering. The process involves stems and leaves. Symptoms of the disease are characteristic and typical:

brown spotting on leaves;
round shape;
small size 2-3 cm;
clearly visible from the underside of the leaf blade;
the spots spread quickly, affecting all parts of the potato;
soon a white powdery coating forms on them, it gradually turns gray and darkens;
the affected tissues die.

Prevention

Measures that prevent the development of the disease help to avoid re-infections and outbreaks of infection. What is needed for this:

Destroy all infected tops by fire.
Fertilize the soil with superphosphate and phosphorus-potassium agents.
Use minimal nitrogen fertilizers.
In autumn, carry out deep autumn plowing.
Perform crop rotation once.
Plant with green manure for the winter.

Treatment measures

To combat the fungus, potato bushes are treated with the following preparations:

0.5% soda ash solution;
Azocene;
Bayleton.

Verticillium wilt, wilt

A fungal disease is one of the most destructive for potatoes, manifesting itself during the flowering phase. Because of it, potatoes quickly wither and die. She initially dies root system. The causative agent is a fungus of the genus Verticillium. Potato losses reach 50%. The optimal temperature for the reproduction and spread of the pathogen is 17-22 degrees. The most severe outbreaks of the disease occur in dry, hot years. Spores persist in soil, tubers, and plant waste. A section of the stem shows a darkened vascular network.

Manifestations of the disease

Symptoms of wilting, what to look for:

Potatoes are wilting
The edges of the leaves turn yellow.
Brown spots appear, bordered by a yellow stripe.
Tubers and stolons die.
On back side leaves, a white coating appears on the stems.
Rapid death of affected plants.

Prevention and treatment:

do not allow the soil to overheat above 28 degrees;
after watering, loosen to a depth of 15 cm;
use mulch, spreading it between rows;
get rid of diseased bushes in a timely manner;
Do not water with cold water in hot weather.