It is impossible to find a gardener who has never encountered diseases and pests of potatoes. What gardeners just don't do to save their crops - they plant a vegetable in barrels and bags, store tubers under hay, and even grow potatoes in a bag. Potato diseases and the fight against them take a lot of time and effort if you do not know a clear algorithm of the necessary actions. Numerous fungi, viruses and bacteria still infect both the plant and the mature crop. So what is the reason and how to cope with this scourge? Description of potato diseases, treatment, photos - all this is presented in the article. As you know, the pests are the carriers of most diseases.
Classification of diseases
Unfortunately, it is not immediately possible to get rid of a single disease even with the most powerful chemicals or with the help of the complete destruction of a plant. This is due to infection not only of mature tubers, but also of the soil, as well as plants at the stage of planting material. That is why it is important to know how to treat potatoes from diseases before planting and how to recognize a particular disease. Depending on the nature of the occurrence of the disease, a certain treatment is used. There are three main types of potato diseases:
- Bacterial - a black leg and rot: brown, ring, wet, mixed internal. These diseases of potato tubers are provoked by the action of microbes that spread from the stems throughout the plant. It is quite difficult to deal with them, because not only the plant needs processing, but also the soil in which it grows. One of the measures against bacterial potato diseases is timely seeding.
- Fungal - potato cancer, late blight, phomosis, fusarium, alternariosis and scab: ordinary, powdery, silver, black. This group is considered the most dangerous. Most often, fungal diseases occur due to pests or improper care of the plant.
- Viral - necrosis of tubers, gothic tubers, mosaic: ordinary, wrinkled, banded. Carriers of these diseases are pests such as aphids, cicadas and Colorado beetles. In the first few years, the results of their vital activity are almost imperceptible, but every year more and more plants become infected, which gradually die.
In the following sections we will give a more detailed description of potato diseases (with photo). Tuber treatment will also be considered.
Brown bacterial rot
The disease causes the vital activity of microorganisms Ralstonia solanacearum. The first signs of infection appear during flowering and tuber formation. Potato disease is recognized by yellowed and fading leaves that become wrinkled and lifeless. The stems begin to fall down and change the green color to brown. With the active reproduction of bacteria, softening and decay of the basal part of the stem occurs. Sprouts gradually split and the veins acquire a brown color of rot.
When cutting the diseased stem, dark fibers can be detected, when pressed, a grayish cloudy mucus will be released. The death of the bushes occurs due to clogging of the veins with a gum mass, which has a high density. Thus, brown bacterial rot can be attributed to vascular diseases of potatoes. On tubers, the disease looks like a softened vascular ring and a large number of brown spots in the core. Rotting of tubers begins during storage. The process is accompanied by secretion of mucus and an unpleasant odor. The affected tuber completely rots and infects neighboring ones.
The fight against the disease is the organization of crop rotation and the introduction of certain drugs. In addition, you can plant potatoes on an infected bed no earlier than five years later. Before planting, seed tubers are carefully sorted and placed in a warm place for 3-4 weeks. This procedure will determine suitable for planting instances. For cutting planting material, only a clean and sanitized knife is used, and healthy tubers are treated with Bactofit, Rizoplan or Polycarbocin for prevention purposes.
Ring rot
Signs of infection with the disease are clearly visible in the potato tuber photo. The manifestation of signs of the disease begins after flowering. Thin shoots begin to turn yellow, and the leaves curl. The infected parts of the plant are not so easy to tear out due to the destruction of the sinewy structure. Since the disease begins to develop from the roots, it is too late to determine the infection. Cutting the tuber, you will see rings on the edges of the core, having a yellow or brown color. By clicking on the affected area, you can notice the release of gray-yellow mucus. When planting such tubers, a poor harvest will be obtained with deformed leaves and thinned stems.
This disease occurs with mechanical damage to the fruit during planting, violation of storage conditions and poor-quality planting material. To date, there is no drug that can overcome ring rot. You can fight it with the help of seeding, making potash and phosphorus fertilizing and regular destruction of diseased plants at the slightest sign of infection.
Wet rot
This disease is difficult to detect in the early stages, since the main blow falls on the tuber core. The cause of the development of wet rot are bacteria that enter the root crop when damaged, and are also transmitted by pests. Potato disease manifests itself as severe softening and rotting of the tuber. At the same time, a very unpleasant and pungent odor is released. Rotting fabrics are first white, then brown and almost black. Moreover, the peel to the last retains its integrity and attractive appearance. In some cases, dark dents may appear on its surface, upon pressing on which a whitish liquid flows. At the slightest sign of damage, the tubers are removed from the total mass of the crop to provide the rest of the potato with protection against diseases and pests. Experienced gardeners noticed a pattern between freezing or overheating of potatoes during storage and their subsequent infection with wet rot.
But how to prevent its development and protect your crop? In this section we will tell you how to process potatoes from the disease.
After harvesting, specimens intended for further planting and cultivation are processed with the Maxim chemical preparation. In addition, try to protect root crops from mechanical damage and exposure to insects.
Mixed Inner Rot
The causes of this disease are no different from other bacterial diseases - improper storage, violation of the temperature regime, mechanical damage - all this provokes the development of harmful bacteria. Symptoms are manifested depending on the kind of bacteria that fall into the tissue membranes of the root crop. At the same time, signs of both ring and brown rot can be observed. In addition, a plaque of gray, pinkish or brown color appears on the affected areas.
The fight against mixed rot is carried out by treating tubers with Fludioxonil and Maxim preparations. The seed material intended for the propagation of potatoes is sprayed with any antibacterial preparation before being sent for storage.
Blackleg
A fairly common disease of potatoes caused by bacteria of the genus Pectobacterium, which settle on many weeds and go on cultivated plants. These parasites are incredibly hardy - they survive at temperatures from +2 ° C to +32 ° C, and in the soil they can be stored for several years until the onset of favorable conditions. Unfortunately, it is impossible to determine infection in the early stages. The rapid development of the black leg occurs in high humidity or in hot weather. Signs of infection appear on the tubers and on the aerial part of the plant: the stem begins to rot, the leaves turn yellow, and the tubers turn black and rot.
In hot weather, a week after infection, the root part of the stem decays, due to which it falls under the weight of its own weight. Slices of stems are covered with mucus. Tuber spoilage begins with the appearance of dark dots, which gradually turn into dark putrefactive spots. The peel of the potato is covered with cracks, from which comes a foul-smelling, sticky liquid. If the tuber surface remains clean, then the infection can be determined by the too light weight of the root crop.
You can defeat the black leg using the drugs "Maxim", "Prestige" and "TMTD". And in order to avoid infection, it is important to follow the basic rules of care and storage of the crop. Crop rotation, quality planting stock, tool disinfection and weed removal are key to a healthy plant.
In general, the fight against bacterial diseases is similar, regardless of the type of bacteria. In the following sections, we will share a photo, description and treatment of diseases of potato tubers of fungal nature.
Common scab
This disease is the result of the activity of fungi of the genus Streptomycetes. The reason for their occurrence is considered to be insufficient care, a high content of lime or sand in the soil, as well as too long hot weather. Infected fruits can be eaten, but their taste and appearance does not change for the better. The surface of the tubers is covered with asymmetric brown sores, which gradually acquire a cork structure and merge into a single spot. When digging potatoes on fresh tubers, you can find a trace of mycelium, which disappears as it dries. The core of the tubers does not change its appearance at all, regardless of the degree of damage. The main measures to combat potato disease, the photo and description of which are presented in this section, are timely crop rotation and proper application of fertilizing.
Ivan Markov, PhD in Biology and Professor at the Ukrainian National University of Science and Technology, found that the use of fresh manure and the excessive use of nitrogen-based fertilizers contribute to the active development of this fungal disease. Therefore, nitrogen stabilizers should be introduced into the soil, as well as manganese and ammonium sulfates. Proper dosage of potassium preparations, calcium chloride and manganese can significantly reduce the harmfulness of scab. However, the amount of the above additives is determined only after a thorough laboratory examination of the soil sample. If this is not possible, then you can give preference to varieties resistant to this disease. For example, "Glow", "Vesta", "Symphony", "Lugovskaya" and others.
Powdery scab
The causative agent of powdery scab is the false fungus Spongospora subterranea. In the people it is also called a mucus because of its appearance - an amoeba-shaped lump is able to move due to plant cells and leads a parasitic lifestyle. Under adverse conditions, it is covered with a protective shell, while in which it can exist for about four years. When damp occurs, the membrane is covered with mucus, which greatly facilitates the process of moving the parasite. Affected roots and tubers become susceptible to putrefactive bacteria and dangerous viruses. The infection of the plant begins with the root system, after which it passes to the stems, leading to their withering. On tubers, the disease manifests itself in the form of white galls and warty pustules. As the disease develops, the sores crack and fill with the powder mass. The relief peel gives the ulcers a star shape. A particularly active development of the disease occurs in a humid environment with a prolonged absence of sunlight.
The fight against diseases and pests of potatoes consists in regular seeding and planting of high-quality material pre-treated with the drug "Maxim". Root crops intended for subsequent planting are harvested only in dry and warm weather. If the soil is infected with powdery scab, planting potatoes in this area is permissible no earlier than seven years later.
Silver scab
This type of scab is caused by fungi of the genus Helminthosporium solani, which affect only the peel of the root crop. At the first stages of the development of the disease, it is quite difficult to detect infection, only with the development of mycelium does brown spots appear on the skin of the tuber. The main danger of this disease is to increase the risk of reinfection with other infections. When the affected tuber gets into the box with planting material, healthy tubers are infected, leading to the development of weakened bushes with thinned stems. You can recognize the appearance of the disease when digging the crop. Having cleared the tuber from the ground, you can find light brown spots of a small size. With the onset of spring, silver dents are formed on the spot, formed during the exfoliation of tissues. With severe damage, the tuber shell loses moisture and is deformed.
The development of the disease occurs with high humidity and high air temperature. At +15 ° C, pathogenic spores develop in an hour. But already at a temperature of +3 ° C, development abruptly ceases. The main ways to protect potatoes are practically no different from those used in previous situations. The only exceptions are preparations for the treatment of seed material - Fundazolum, Nitrafen, Titusim. Moreover, the pickling is carried out immediately after harvest, before being sent for storage.
Black scab
Rhizoctonia, also called this disease, affects not only tubers, but also other parts of the plant. This is the main difference from other fungal diseases such as scab. Infection occurs due to poor-quality substrate, and its active development occurs in the winter season. Black scab harms not only potatoes, but also neighboring crops planted in cold soil. Young potato sprouts have a weakened and depressed appearance. Root crops are covered with black exfoliating dots, similar to warts, which merge into single spots with a more severe lesion. Brown sores form on the stems of the plant, the basal part is covered with a white coating, and the root system is roughened. Due to the massive distribution of pores, you can lose the entire crop in a fairly quick time.
Favorable conditions for the development of black scab is considered increased dampness and cold. Therefore, it is important not to rush with planting potatoes - wait until the earth warms up well and dries out. Planting material is carefully scanned for the purpose of rejecting defective tubers. Before planting, the tubers are treated with fungicidal preparations, and after harvesting the leaves are removed from the site. Fertilize the soil with exclusively rotted organic top dressing. An infected bush can be treated with strong chemicals such as Kulfugo, Mancozeb and Fenoram Super.
Alternariosis
Dry spotting is caused by fungi of the genus Alternaria, the active development of which occurs in dry weather at high air temperatures. You can determine the infection already during flowering. Symptoms of the disease are clearly manifested throughout the vegetative period. Alternaria is affected by leaves, stems, root system and tubers. Brownish spots appear on the leaves and stems, having a round or triangular shape. Due to the easy spread in the wind, a fairly rapid infection of almost all cultivated plants on the site occurs. The main reason for this development of the disease is the constant jumps in the humidity of the air and soil, the excess phosphorus content and the lack of potassium and nitrogen fertilizing.
Young tubers become infected with dry spotting upon contact with the soil during the harvesting process, while more mature fruits become infected when the fungus gets on the lesions and abrasions. You can destroy the fungus by immediately destroying the source of infection using the chaffinch plowing method. It is also important to plant potatoes as far as possible from tomatoes and other nightshade crops. Having found the slightest signs of infection on young sprouts, immediately treat the plants with a fungicidal preparation. For a better spread of fungicide, treatment is preferably carried out in rainy weather. There are varieties of potatoes that are resistant to this disease: "Lina", "Victory", "Volzhanka".
Potato cancer
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To protect plants from the mass distribution of parasites, the plot is treated with bleach, after which crops are planted on it. Cancer-resistant crops may be preferred, such as Spark, Twinkle, Temp or Zorka.
Dry rot
Fusarium disease, the scientific name for this disease, develops with improper storage, gross violations of agricultural technology and mechanical damage to tubers. Bushes of the infected plant wither and cease to be viable. On a section of a diseased process, a dark ring can be seen. Symptoms of the disease also appear as clearly visible brown spots on the tubers, which eventually become dents. The wrinkled skin on the damaged areas is gradually covered with white pubescent coating due to the action of pathogenic fungi, as shown in the photo of a potato disease.
The fight against them involves the use of fungicidal preparations that process planting material. Compliance with the rules of care and the prevention of mechanical damage allows protecting plantings from the spread of the disease.
Late blight
One of the most common and insidious diseases of potato affects the entire plant, starting with foliage during the formation of buds. They learn about the appearance of the disease by spots on leaves that have a felt structure and a brownish tint. Spots appear on the back of the sheet, gradually expanding over its entire area and becoming covered with white bloom. Affected stems have long brown streaks on their surface. A diseased plant is not able to develop due to the beginning processes of decay.
Potato disease develops, the description and photo of which is indicated above, with high humidity and lack of ventilation. Thus, the main preventive measure is the normalization of the irrigation regime and regular loosening of the soil. When the soil dries up, the fungi slow down their development, however, this does not mean a complete victory over them. Affected bushes must be treated with infusion of garlic or boron mixture.
Ordinary mosaic
The development of potato disease, which is described in this section, is due to the simultaneous action of several viruses. Favorable conditions for the spread of this disease are mechanical damage and the presence of pests. As shown in the photo of potato disease, young leaves are covered with small light green dots that have an asymmetric shape. With the development of the disease, the color of mottling changes to darker, and the disease spreads to the entire bush.
Wrinkled mosaic
The infected leaves of the plant swell and form numerous folds. This disease occurs due to a disturbed outflow of waste products. Three years after infection, the potato bush becomes dwarf, and its leaves become corrugated. A diseased plant is not capable of developing buds and fruits. Its growing season will end much earlier than in healthy plants.
Gothic
The development of this disease is due to the entry of spindle-shaped veroid virus into the tissues. The virus has a detrimental effect on tubers, changing their shape and taste. Potato leaves do not stretch and develop properly, and the bush itself does not grow well. The edges of the leaves acquire a purple hue. Red-skinned varieties of potatoes gradually lose their brightness. In addition, the fruits take the form of a spindle, as a result of which this disease is called "spindle-shaped".
Necrosis
For the development of tuber necrosis, the tobacco rattle virus is responsible, which reduces the starch content in the tuber. The characteristic symptoms of infection are manifested in the form of light specks on leaves and dark spots on mature tubers, as shown in the photo of potato disease. Unfortunately, this disease is not amenable to treatment, as is the case with other viral infections. For prevention, it is permissible only to remove weeds and destroy insects that can spread the disease to healthy plants. In addition, the relationship of high humidity and high sand content in the soil with the active development of this disease is noted.
So, we talked about all the diseases of potato tubers. You can find photos and descriptions of the various conditions of this vegetable in this article.