Why Potatoes Rot During Storage, And How To Avoid It? Potato Diseases. Protection Measures. Photo

2023 Author: Ava Durham | [email protected]. Last modified: 2023-11-27 07:13

Despite the fact that potatoes are on sale in the markets all year round, I want my own - incredibly tasty, boiled and environmentally friendly potatoes. But often home-grown potatoes cannot be stored until spring. Already after the New Year holidays, increased "spoilage" of tubers begins, an unpleasant smell appears in the storehouse and even (as they say in newspapers) an explosive atmosphere when gas accumulates in a closed room. What causes rotting tubers, and how to avoid it? Let's look at the reasons and develop a scheme for preserving the harvest of our favorite potatoes.

Content:

• Fungal diseases of potato tubers during storage
• Potato bacterial diseases during storage - rot
• How to keep potatoes from rotting?

Fungal diseases of potato tubers during storage

Potatoes are affected by fungal and bacterial diseases during the growing season and during storage. Of the fungal infections, the greatest harm is caused by late blight, fusarium, alternaria.

Late blight

Late blight is one of the most dangerous fungal diseases. The fungus infects the crop even during the growing season (it is able to destroy up to 70% of the crop in a short period) and is transferred with tubers to storage sites.

Hard gray spots appear on the surface of the tubers, clearly visible on the pulp when the potato is cut. With the growth of the mycelium, the tuber begins to rot.

Protection and control measures

If plants are damaged during the growing season, it is necessary to spray the potatoes with 2% bordeaux raster liquid. If you suspect a complex lesion (that is, several types of fungal diseases) use biofungicides "Fitochit", "Fitosporin-M", "Planriz", etc.

Optimal storage conditions are good ventilation, lack of light, air humidity within 80-90%, air temperature not higher than + 2 … + 3 ° С. For the development of late blight, a high temperature is required (+ 20 … + 24 ° C). Therefore, it is not recommended to store potatoes in residential areas with high temperatures.

The best potato varieties resistant to late blight are: Lasunok, Temp, Scarlet, Aspia, Vestnik, Golubizna, Lugovskoy, Resurs, etc.

Fusarium (dry rot)

Like late blight, it affects the tops and tubers even during the growing season. Excessive soil moisture (prolonged rains) at high temperatures contributes to the rapid spread of the disease.

During the growing season, external signs appear in the form of gray spots on the leaf surface, general wilting and drying of plants. The affected plant withers literally in one day. A striking distinguishing feature of the defeat of the culture by Fusarium is a bluish-black ring on the cut of the stem (vessels clogged with fungal hyphae).

Tubers stored for storage are covered with a whitish bloom, or the skin in places where gray-brown spots are formed wrinkles and becomes dry (without obvious reasons for violating the rules for storing products). The section shows dark voids filled with mycelium.

Protection and control measures

The level of harmfulness is very high. The mycotoxins of this disease persist not only in the harvest, but also in processed products. They affect the human nervous system, cause the death of birds and animals. Tubers (like other products - flour, juices, jams, fodder for animals) affected by fusarium cannot be used for food.

During the growing season, plants are sprayed with a 1-2% solution of Bordeaux liquid, solutions of biofungicides (Fitosporin-M, Fitochit, Baktofit, Integral, Planriz).

The optimal storage conditions are the same as for protection against late blight. It is recommended to treat the tubers with Fitosporin when storing them for storage (biofungicide does not affect human and animal health). Carry out a systematic bulkhead of potatoes (carefully so as not to disturb the outer skin, since the infection quickly spreads to neighboring tubers).

The best varieties resistant to this disease are: "Detskoselsky", "Priekulsky early", "Berlichingen", "Nevsky", "Skarb", etc.

Alternaria (dry spot of potatoes)

In terms of the level of damage to potato yields, this disease is similar to late blight. It affects all parts of the plant (stems, leaves, tubers). Most often, it is medium and late varieties of potatoes that are affected by dry spotting, that is, those recommended for laying for winter storage.

The lesion during the growing season manifests itself on leaves and stems in the form of large concentric spots. The spots gradually become brown or dark brown with a brown tint. Depressed spots appear on the surface of the tubers, which gradually wrinkle. On the cut of the tuber, the affected areas are necrotic, differing from healthy tissue in hard, dense pulp of black-brown color.

Protection and control measures

When preparing for planting, treat the tubers with biological products "Planriz", "Baktofit", "Integral", "Fitosporin-M" and others from the recommended list. During the growing season, carry out the same treatments as in previous diseases.

The optimal conditions for storing potatoes are the same as when protecting against the previously listed diseases.

The best potato varieties resistant to this disease are: Gatchinsky, Ogonyok, Zarevo, Lyubava, Bronnitsky, Sibiryak, Severyanin, Russian Souvenir, Effect, etc.

The above-described diseases (late blight, fusarium, alternaria), as well as rhizoctonia, common scab, phomosis, anthracnose are spread mainly through seed. Therefore, planting and cultivation of precisely resistant to diseases, zoned to external conditions varieties is the key basis for the safety of tubers during winter storage until the next harvest.

Potato bacterial diseases during storage - rot

In addition to fungal, potatoes are susceptible to bacterial diseases. The source of damage is putrefactive bacteria, which can turn tubers into a gray decaying mass with a pungent unpleasant odor in 2-3 months.

Bacterial infections develop when the storage conditions of products are violated (poor ventilation, high temperature and humidity). Pathogenic bacteria penetrate into the tuber through external damage (cracks, cuts when digging potatoes, etc.).

The bacterial infection is transmitted mainly through the seed, but during the growing season it affects not only tubers, but also vegetative organs (stems, leaves, roots, stolons).

In the years of epiphytoties, bacterioses kill up to 50% of the crop in the field and up to 100% during storage. Most of all, healthy tubers are infected with phytopathogenic bacteria during preparation for planting, inaccurate harvesting (with the application of various kinds of mechanical damage) and sorting before storage.

Of bacterial diseases, most often, potatoes are affected by wet bacterial rot, button rot, ring rot, black leg.

Blackleg

Crop losses can range from 1-2% to 50-70%. Bacteriosis affects the vegetative parts of the plant and tubers. It is difficult to get rid of bacterial infection, due to the fact that there are still no varieties that are resistant to this disease.

When the infected material is planted, many potato seedlings fall out or seedlings are weak, develop poorly. With age, the lower part of the stem turns black (hence the name of the disease "black leg"), the leaves turn yellow, become brittle, hard. The leaf blades are curled up in a boat, the leaf itself grows at an acute angle to the stem. During excavation, the mother tuber is rotten, slimy.

Ring rot

The bacterial infection affects all parts of the potato plant. The external manifestation of the disease during the growing season, like that of the black leg, is the wilting of the aerial part and decay of the maternal tuber.

A distinctive feature is the leaf mosaic in pale yellow tones and swollen leaf nodes. 1-2 weak stems develop from the mother tuber. Pitting rot is visible on diseased tubers during harvesting; when cut, diseased tuber tissue has an annular lesion of the vascular tissue or yellow subcutaneous spot.

Brown rot

Mucous bacteriosis is one of the most severe bacterial diseases. Differs in the rapid course of the disease. About 200 species of plants are affected, including potatoes.

Distributed mainly in regions with a warm climate. The source of infection are diseased tubers and soil, weeds, irrigation water. The causative agent of the disease penetrates into the tubers of a new crop through mechanical damage, stomata, fills the vessels of stems, stolons, roots with a mucous mass, which causes wilting and death of the plant.

Symptoms of the disease appear externally in the flowering phase in the form of wilting of leaves at the ends of the shoots. Green leaf blades acquire a brownish tint, twist into a half-tube and hang. The root part of the stems softens. The bacterial mucus accumulated inside (in the vascular ring) is released through the ruptures of half-rotted stolons, stems, and rotten tubers.

Measures for protection and control of bacteriosis (rot)

All bacterial rot (as shown in the diseases described above) are characterized by the general wilting of underdeveloped potato bushes during the growing season and the rapid decomposition of the tubers to a slimy mass during storage. A significant part of rot is soil pathogens and is able to persist in the soil for a long time, affecting the planted healthy material.

Therefore, the main measures for protecting the culture from bacteriosis are the use of zoned potato varieties resistant to damage, the mandatory autumn-spring disinfection of the soil before planting, the processing of planting material to suppress soil infection during germination of tubers, the preparation of storage facilities, and the sorting of tubers before storage.

The best varieties are resistant to this complex of diseases: "Skarb", "Nevsky", "Rosinka", "Lazurit early", "Bronnitsky". Resistant to bacterial rot and mid-season varieties "Rodnik", "Resource", "Vestnik", "Golubizna", etc.

How to keep potatoes from rotting?

Based on the foregoing, it is clear that the poor preservation of tubers in the cold period begins with a violation of the technology of growing and harvesting this crop. The following significant reasons are the unpreparedness of the storage (cellar, basement, vegetable pit, balcony, loggia, etc.) for storing products, incorrect selection of potato varieties, violation of the storage technology.

It is these reasons that cause damage to tubers with various fungal, mold and bacterial diseases; contribute to their rapid spread and loss of yield not only during cultivation, but also during storage.

To protect potatoes from rotting during storage, it is necessary to properly prepare the area for this crop. Apply fertilizers, top dressing, treat diseases and pests only in accordance with technology and recommendations.

For planting (for the purpose of long-term storage of tubers in the cold period), it is necessary to use only zoned, medium and late varieties (in terms of ripening), resistant to fungal and other diseases. Before planting, the seed must be processed.

During the growing season, treatment of plants should be carried out at the very beginning of the disease, and not wait for mass destruction. It is more practical to carry out preventive treatments according to a previously worked out scheme.

Only absolutely healthy, undamaged tubers should be stored in prepared storage facilities.

Fulfillment of the basic requirements for the preparation of tubers, their planting, care and harvesting will minimize crop damage during winter storage.

Rules for protecting potato tubers from decay during storage

1. When planting several varieties on a site, each is harvested separately.
2. Only mid-ripening, mid-late and late varieties of potatoes are laid for storage. The early varieties after December are already unsuitable for human consumption and remain as planting material or used for animal feed.
3. In order for the tubers to mature well, the potato tops are mown 10-15 days before harvesting.
4. Digging of potatoes is carried out in dry, sunny weather. If the weather is rainy, then the potatoes are slightly dried and manually cleaned of adhering dirt (to avoid mechanical damage, through which a fungal or bacterial infection can penetrate into the tuber).
5. Mechanically damaged and diseased tubers are immediately laid in a separate heap.
6. Healthy, intact potatoes are transferred under a canopy (covered from the sun) or in a dark room with good ventilation for 5-7 days to ripen (coarse) the upper skin. Protection from light is essential to keep the potatoes from turning green. Solanine is formed in the light, and such tubers cannot be used for food.
7. The storage facility is disinfected and dried before being put into storage.
8. Tubers, dried and cleaned from dirt, can be treated with biopreparations "Fitosporin" and "Antignil" to protect them from decay during storage, which will reduce the infectious background. They are harmless to humans and animals.
9. If the potatoes are stored in bulk, then it is advisable to put 1-2 rows of beets on top. It will absorb excess moisture, which will protect the potato tubers from decay. The beets will not be affected.
10. It is more expedient to store potatoes in boxes (each variety separately).
11. Once a month, a bulkhead of tubers is carried out, removing diseased ones.
12. Good ventilation will protect stored products from infection and decay.
13. The air temperature in the storage must be maintained at the level of + 2 … + 4 ° C, and the humidity 80-91%. With high humidity in the room, you can place, in addition to ventilation, a container with quicklime and change the filler if necessary. With the arrival of spring, the temperature in the store may rise. Frozen water in plastic bottles with a capacity of 3-5 liters will help reduce it. Containers with ice are placed in different places. Ice in closed containers will gradually melt and cool the room.

Dear readers, if you still have questions after reading the article, we invite you to a discussion on the forum or in the comments to this material. Many experienced gardeners have their own secrets to effectively protect potatoes from fungal and bacterial infections. Your advice will be greatly appreciated.