Potato wet rot causes. Wet rot of potatoes. Virus diseases of potatoes
Photo: Wet rot of potatoes
Description of the disease:
A widespread bacterial disease of potato tubers. Infection occurs when potatoes are grown in waterlogged areas, and the symptoms of the disease appear when tubers are not properly stored in storage. Under favorable conditions for the development of the disease (high air humidity of 90% and high air temperature above 17 degrees C), tubers can rot in a week.The disease manifests itself in the form of soft and hard black rot.
Symptoms of the disease:
With soft rot, the pulp of the affected tuber breaks up into individual cells, gradually turning into a slimy mass with a slight unpleasant odor. If the tuber is not completely affected, then the healthy tissue is separated from the affected tissue by a brown border. The color of the tubers changes during the development of the disease, from light to dark brown, sometimes pink. The skin usually remains intact.With hard rot, the affected tissues turn dark in color, voids form inside the tuber. The fabrics gradually harden. Mucus and smell are absent.
Control and prevention measures:
- harvest in dry weather- dry the tubers well before storage
- cultivate soft rot resistant varieties
- observe the correct storage conditions for potatoes
- at the first signs of infection, destroy the infected tubers in a timely manner.
Wet bacterial rot is a group of similar diseases. They can infect any type of plant. They are also found on root crops - potatoes, carrots, onions, turnips, parsley, parsnips, celery and on ornamental plants, in particular on orchid leaves.
The first signs of the disease - wilting of the stem and watery spots on the root crops appear even in the field.
The disease is caused by multiple types of bacteria, the most dangerous of which are the pathogens of the black leg Erwinia phytophthora (App.) Berg and E. carotovora (Jon.) Holl. The first bacterium becomes the cause of the disease during the growth of potatoes, and the second during the storage of the crop. On a tuber infected with a bacterium, weeping brown or black spots can be seen. Soon, rotting begins on the entire tuber. It softens, its consistency becomes like a slimy porridge with an unpleasant odor. The infection, getting to a neighboring tuber through mechanical damage or wounds from diseases on the skin, penetrates into the tissues and infects them. The process starts over. From a diseased tuber, nearby ones become infected - the disease spreads throughout the store. Frozen root crops are especially sensitive to the disease.
The development of the disease is facilitated by improper storage of the crop - too high temperature, air humidity with insufficient ventilation and excessive doses of nitrogen fertilizers applied during the growth period.
Bacterial wet rot on onions is caused by Dickeya chrysanthemi (synonym: Erwinia chrysanthemi), Pectobacterium carotovorum subsp. carotovorum (synonym: E. carotovora subsp. carotovora). Disease-damaged scales of mature bulbs appear soaked in water. Their color varies from pale yellow to light brown. In the future, the scales become soft and sticky, the bulb rots. By pressing on the bulb, you can get a thick liquid with an unpleasant odor.
Onions can become infected at any time from growing in the field to storage, including transportation. The source of the disease can be infected soil or crop residues. Drops of irrigation water, rain and insects carry the infection to neighboring plants. The infection penetrates into the bulb only through damage to the integumentary tissues from sunburn or mechanical damage received during transplantation. Onion fly larvae can transfer bacteria from diseased plants to healthy ones.
High air temperatures (20-30°C) and high air humidity contribute to the rapid spread of infection. During transport and in storage, factors such as self-warming and sweating of the bulbs are added to these. Exposure to low temperatures in the field, excess nitrogen fertilizers, and late harvesting help the spread of bacteria. Healthy bulbs become infected from diseased ones.
Very often, wet bacterial rot occurs on indoor flowers. The bacteria of this disease secrete the enzyme pectinase, which destroys and softens the tissues of the plant. Soon, individual affected areas or the plant as a whole turns into a rotting mass. The infection penetrates into plant tissues through mechanical damage on the fleshiest parts of the plant. Outwardly, it looks like rapidly growing gray, brown or black spots. Tubers and bulbs emit an unpleasant odor.
The spread of the disease is facilitated by elevated temperature, air humidity and excess nitrogen-containing fertilizers.
Control measures
Pathogens are well preserved in the soil and can be spread not only by pests, but also by the tool used to treat plantings.
In autumn, the soil should be treated with bleach, chloropicrin or formalin. Tools are disinfected with alcohol after each use.
Fighting the disease during storage of the crop begins in advance. The room is cleaned of debris and treated with formalin solution. The walls are whitewashed with a mixture of lime and blue vitriol. Check ventilation and humidity levels.
At room conditions, soil moisture is monitored, the amount of nitrogen fertilizers applied is controlled, the rotten parts of plants found are removed with a part of healthy tissue, and the cut points are disinfected. Treated with alcohol and a cutting tool.
WET ROT
plant disease caused by bacteria to-rye through wounds get into fabrics rast. and destroy the intercellular substance. The tissues are destroyed and turn into a slimy mushy mass with an unpleasant putrefactive odor. Mg affects carrots, onions, turnips, parsnips, parsley, potatoes, etc. The disease is observed during growth and especially. during storage. Control measures: proper fruit change, introduction of resistant varieties, selection of healthy roots for storage and clubbing. Protect tubers and roots from damage. Store them in dry ventilated rooms with a temperature of 1-3 ° C . Disinfect storage facilities. Avoid excess nitrogenous fertilizers.
Agricultural dictionary-reference book. - Moscow - Leningrad: State publishing house of collective and state farm literature "Selkhozgiz". Editor-in-Chief: A. I. Gaister. 1934 .
See what "WET ROT" is in other dictionaries:
WET ROT- see Wet rot disease is caused by bacteria that settle on tubers damaged by frost or sunlight. Tubers quickly rot, darken, emit an unpleasant odor. The disease progresses strongly at high temperature (20 ... ... Encyclopedia of seeds. vegetable crops
See Evils of the tree. Samoilov K.I. Marine Dictionary. M. L .: State Naval Publishing House of the NKVMF of the USSR, 1941 ... Marine Dictionary
wet rot- Erwinia caratovora, bacterium, potato pest Biotechnology topics EN erwinia caratovora …
wet rot- wet rot, a ubiquitous disease mainly of the succulent organs of plants - tubers, root crops, bulbs, heads of cabbage; arises and develops, as a rule, under a joint simultaneous or sequential influence ... ... Agriculture. Big encyclopedic dictionary
WET ROT- ubiquitous disease arr. succulent organs of early tubers, root crops, bulbs, heads of cabbage; arises and develops, as a rule, under the joint simultaneous or sequential action of bacteria (Erwinia caratovora, ... ... Agricultural Encyclopedic Dictionary
BACTERIAL ROTT OF CARROT WET; ROOT ROT SOFT CARROT- English bacterial soft rot of carrot German Bakterienfäule, Mohre; Naßfäule, Mohre; Weichfäule, Mohre French maladie bactérienne de la carotte; pourriture molle de la carotte causative agent: Erwinia carotovora (Jones) Holl. cm …
ROT OF WHITE TOBACCO AND WET shag; ROTT OF STEMS OF SCLEROTINIOSIS OF TOBACCO AND Makhora; SCLEROTINIOSIS OF TOBACCO AND MAKHORKA- English cottony rot of tobacco; stem rot of tobacco (Sclerotinia); white mouth of tobacco German Sklerotinienkrankheit, Tabak; Stengelfäule, Tabak (Sclerotinia) French pourriture blanche des tiges du tabac; sclerotiniose du tabac… … Phytopathological dictionary-reference book
Long-tailed flax disease caused by the fungus Sclerotinia sclerotiorum (Lib.) Massee (syn. Sclerotinia libertiana Fuck.), the marsupial stage of Whetzelinia sclerotiorum (Lib) Korf. et Dumont.); manifests itself on vegetative fallen plants and ... ... Technical Translator's Handbook
white wet rot of fiber flax- 45 White soft rot of long-lived flax: A disease of long-lived flax caused by the fungus Sclerotinia sclerotiorum (Lib.) Massee (syn. Sclerotinia libertiana Fuck.), the marsupial stage of Whetzelinia sclerotiorum (Lib) Korf. et Dumont.); appears... ... Dictionary-reference book of terms of normative and technical documentation
ROOT ROT WET SCLEROTINIOUS CITRUS; FRUITS WET ROTT OF CITRUS- English cottony fruit rot of citrus plants; twig blight of citrus plants (Sclerotinia sclerotiorum) German Fruchtfäule, Agrumenbäume (Sclerotinia); Zweigkrebs, Agrumenbäume French.pourriture des fruits (et des branches) des agrumes… … Phytopathological dictionary-reference book
Wet bacterial rot of potatoes. Description of the disease.
Potato (Solanum tuberosum) is a plant that forms, along with poisonous fruits, quite harmless and tasty tubers. They have gained fame for a very long time - 14 thousand years ago, the South American Indians, who lived in the territories of modern Venezuela, Colombia and Peru, began to use these tubers as a food product. They were collected (dug up), partially boiled immediately (in fresh or salted water), partially dried (under the hot Sun of the equatorial zone).
In the middle of the XVI century, the Spanish conquistador, priest and chronicler (author of the Chronicle of Peru) Pedro de Ciesa de Leon introduced Europeans to the Potato. (Journalists are often mistaken in attributing this merit to Christopher Columbus, who died in 1506.) Cieza de Leon not only described in detail the use of a strange plant by the Indians, but also brought its tubers to Spain. From there, it quickly spread to the north and east.
However, the population of the Old World for the most part considered the Potato an ornamental crop or, at best, fodder (for pigs). Only the Frenchman Antoine-Auguste Parmentier (1737-1813) managed to overcome these delusions with personal, active, broad propaganda, and in 1772 the medical faculty of the University of Paris proclaimed the edibility of tubers for humans.
The tsarist government in Russia had to accustom the peasants to the cultivation of potatoes for a long time, because due to mass poisoning with fruits, people refused it, called it a “devil's apple”, and declared eating it a direct and conscious sin. The forced introduction of plantings in the districts of the Non-Black Earth Region, the Volga Region, the Urals was met by the so-called "potato riots" - in 1834, in 1840-1844 ... It helped, in the end, sending free brochures-instructions to the villages and villages (they were printed huge circulation for that era - 30 thousand copies!). to the end XIX century Potatoes occupied 1.5 million “state tithes” throughout the Russian Empire (each equal to 80 × 30 = 60 × 40 = 2400 square sazhens = 1.0925 hectares) and was awarded the nickname “second bread”.
In the tropics at home, the problem of tuber conservation was ignored, because they saw:
First, the Potato is a perennial plant;
- secondly, in 3 months a new crop will ripen;
- thirdly, its specific gravity is not very large - 150-250 centners per hectare.
This problem is acute in temperate latitudes, where:
- firstly, Potatoes are grown as a 1-year-old crop;
- secondly, the ripening period of the new crop is at least 4 months;
- thirdly, the average yield can be 250-350 (and the maximum - 400-800) centners per hectare.
And it turned out that tubers brought to storage (of any type - pile, bin, pile, heap, embankment, cellar, basement, underground, trench, closet, pit) tubers are capable of infecting wet bacterial rot.
She "clings" to them even in the field, and extremely willingly, if:
Excessively wet (and therefore sticky) earth blocks normal air exchange, that is, “suffocates” them;
- after removal from the soil, the tubers were left to spend the night on it without shelter and, as a result, they became cold (or even froze) by morning;
- they are damaged by excessive solar radiation;
- damage is mechanical in nature;
- the field is "tormented" by some other infectious disease [examples: bacteriosis, brown bacterial rot of stems, ring rot (bacterial), scab (bacterial or fungal), late blight (fungal), "black leg" (fungal) - see relevant articles in our Garden Encyclopedia] or ditylenchus (stem nematodes = thin white worms 8-14 mm long, Latin name Ditylenchus destructor).
The causative agents of wet rot of stored potato tubers can be different types of bacteria. Previously, Erwinia carotovora often played this role. subsp . atroseptica and Pseudomonas xanthochlora. Recently, mixed rots have become noticeable:
Bacterial. Provided by the joint "work" of species from the genus Pectobacterium (in particular, Pectobacterium phytophthorum) and from the genus Corynebacterium (in particular, Corynebacterium sepedonicum);
- Phytophthora-bacterial (typical for the starting part of the storage period). It is excited by the fungus Phytophthora infestans in "commonwealth" with bacteria from the genera Bacillus, Pectobacterium, Pseudomonas;
- late blight-fusarium. Its "co-authors" are the fungus Phytophthora infestans and fungi from the genus Fusarium;
- fomosa-bacterial (fixed not annually). The fungus Phoma exigua and bacteria from the genera Bacillus and Pectobacterium are “responsible” for it;
- phomose-fusarium. Synergistic result of the "collective" activity of the fungus Phoma exigua and fungi from the genus Fusarium;
- Fusarium-bacterial (dry or wet - depends on storage conditions). They are provoked by the combined "labor" of fungi from the genus Fusarium (Fusarium coeruleum, Fusarium c u lmorum, Fusarium sambucinum, Fusarium semi t ectum, Fusarium solani, etc.) and bacteria from the genera Bacillus, Pectobacterium, Pseudomonas.
Sharp fluctuations in temperature in storage "encourage" the development of wet bacterial rot. In the upper layer (25-30 centimeters thick) of the pile, the relative humidity of the air is usually increased, which also favors the acceleration of the destructive process. If it reaches 90% and the temperature does not fall below 20-25° C , - the tubers will rot in a week.
Symptoms of wet bacterial rot of potatoes.
Spots are observed on the skin of the tuber - soft and moist to the touch. (And sometimes it doesn't show anything.)
His flesh gradually:
Emits an unpleasant (albeit weak) stench;
- acquires a dark brown color, sometimes pink. If not the entire volume of the tuber is affected, then the junction with healthy tissue is “marked” on the cut with a distinct brown border;
- becomes soft, raw and viscous, that is, it turns into mucus (slurry).
A liquid is released from a rotting tuber - and neighboring potatoes that come into contact with it also begin to fall ill. Thus, a focus of "infection" is formed. It may not be the only one in this heap if the rules for laying the crop were violated.
Self-heating of the hearth is associated with rotting tubers, from which it “flares up” even more.
Measures for the control and prevention of wet bacterial rot of potatoes.
1. The “State Register of Breeding Achievements Approved for Use” in Russia as of January 31, 2013 contains about 350 potato varieties out of about 5 thousand that exist today in the world. Therefore, there is ample opportunity to choose a variety that is more resistant to this disease - for example, "Pigeon".
2. Based on information about the optimal harvesting time, time it for dry weather (not necessarily bright sunny, but warm). In particular, "Pigeon" belongs to the middle-late varieties, that is, you can start digging up its tubers 95-110 days after planting.
2a. All harvesting operations should be carried out with care, minimizing the number of injuries caused to tubers by tools, equipment and/or machinery.
2b. After removing the tubers from the ground, arrange them to dry in the open - and in no case leave them there overnight if it is expected to be cool.
3. Carefully sort the crop, while cleaning it from soil residues and plant debris (tops, straw).
4. For industrial scale, a special technology for storing potatoes has been developed, which can also be followed in the private sector. It includes 4 phases:
4a) the healing period, when the lesions heal and infected tubers appear. Lasts 15-18 days. Temperature from 18-20° C gradually reduce by the end of this period to 10-12 ° C . Ventilation is also necessary so that the surfaces of the tubers become completely dry. Its mode is determined by their initial state. Optimal is a 40-50-minute session repeated 5-6 times a day at a flow rate of 100-150 cubic meters of air per 1 hour per 1 ton of "bulb";
4b) cooling period. The recommended rate of temperature decrease is 0.5°C per day, but if there were a lot of rejected tubers, then it is better to double it. Final target - 3-4°C for seed, 4-6° C for table potatoes;
4c) the main phase, during which it is not necessary to change the air parameters;
4d) rise in temperature up to 8-15° C before unloading from storage for planting (or for sale). Reduce ventilation or stop altogether, due to which a leisurely self-heating of the collar should occur.
5. It is impossible to abuse the bulkhead, because chilled tubers are easily damaged. However, it is needed in order to timely identify and eliminate foci of the disease.
5a. The first one is advised to be done 4-6 weeks after laying, the next ones - based on the results of a visual-manual check of the top layer of the collar. If you need to urgently sort out the entire mass of the crop - do not neglect the subsequent drying.
5 B. It is useful to accompany the bulkhead with dusting of healthy tubers, for which dry ash from burning firewood or finely ground phosphorite flour is used (particle sizes up to 0.18 mm). Estimated consumption - 10 kilograms per 1 ton of potatoes.
Wet bacterial rot of potatoes. Description of the disease.
Potato (Solanum tuberosum) is a plant that forms, along with poisonous fruits, quite harmless and tasty tubers. They have gained fame for a very long time - 14 thousand years ago, the South American Indians, who lived in the territories of modern Venezuela, Colombia and Peru, began to use these tubers as a food product. They were collected (dug up), partially boiled immediately (in fresh or salted water), partially dried (under the hot Sun of the equatorial zone).
In the middle of the XVI century, the Spanish conquistador, priest and chronicler (author of the Chronicle of Peru) Pedro de Ciesa de Leon introduced Europeans to the Potato. (Journalists are often mistaken in attributing this merit to Christopher Columbus, who died in 1506.) Cieza de Leon not only described in detail the use of a strange plant by the Indians, but also brought its tubers to Spain. From there, it quickly spread to the north and east.
However, the population of the Old World for the most part considered the Potato an ornamental crop or, at best, fodder (for pigs). Only the Frenchman Antoine-Auguste Parmentier (1737-1813) managed to overcome these delusions with personal, active, broad propaganda, and in 1772 the medical faculty of the University of Paris proclaimed the edibility of tubers for humans.
The tsarist government in Russia had to accustom the peasants to the cultivation of potatoes for a long time, because due to mass poisoning with fruits, people refused it, called it a “devil's apple”, and declared eating it a direct and conscious sin. The forced introduction of plantings in the districts of the Non-Black Earth Region, the Volga Region, the Urals was met by the so-called "potato riots" - in 1834, in 1840-1844 ... It helped, in the end, sending free brochures-instructions to the villages and villages (they were printed huge circulation for that era - 30 thousand copies!). to the end XIX century Potatoes occupied 1.5 million “state tithes” throughout the Russian Empire (each equal to 80 × 30 = 60 × 40 = 2400 square sazhens = 1.0925 hectares) and was awarded the nickname “second bread”.
In the tropics at home, the problem of tuber conservation was ignored, because they saw:
First, the Potato is a perennial plant;
- secondly, in 3 months a new crop will ripen;
- thirdly, its specific gravity is not very large - 150-250 centners per hectare.
This problem is acute in temperate latitudes, where:
- firstly, Potatoes are grown as a 1-year-old crop;
- secondly, the ripening period of the new crop is at least 4 months;
- thirdly, the average yield can be 250-350 (and the maximum - 400-800) centners per hectare.
And it turned out that tubers brought to storage (of any type - pile, bin, pile, heap, embankment, cellar, basement, underground, trench, closet, pit) tubers are capable of infecting wet bacterial rot.
She "clings" to them even in the field, and extremely willingly, if:
Excessively wet (and therefore sticky) earth blocks normal air exchange, that is, “suffocates” them;
- after removal from the soil, the tubers were left to spend the night on it without shelter and, as a result, they became cold (or even froze) by morning;
- they are damaged by excessive solar radiation;
- damage is mechanical in nature;
- the field is "tormented" by some other infectious disease [examples: bacteriosis, brown bacterial rot of stems, ring rot (bacterial), scab (bacterial or fungal), late blight (fungal), "black leg" (fungal) - see relevant articles in our Garden Encyclopedia] or ditylenchus (stem nematodes = thin white worms 8-14 mm long, Latin name Ditylenchus destructor).
The causative agents of wet rot of stored potato tubers can be different types of bacteria. Previously, Erwinia carotovora often played this role. subsp . atroseptica and Pseudomonas xanthochlora. Recently, mixed rots have become noticeable:
Bacterial. Provided by the joint "work" of species from the genus Pectobacterium (in particular, Pectobacterium phytophthorum) and from the genus Corynebacterium (in particular, Corynebacterium sepedonicum);
- Phytophthora-bacterial (typical for the starting part of the storage period). It is excited by the fungus Phytophthora infestans in "commonwealth" with bacteria from the genera Bacillus, Pectobacterium, Pseudomonas;
- late blight-fusarium. Its "co-authors" are the fungus Phytophthora infestans and fungi from the genus Fusarium;
- fomosa-bacterial (fixed not annually). The fungus Phoma exigua and bacteria from the genera Bacillus and Pectobacterium are “responsible” for it;
- phomose-fusarium. Synergistic result of the "collective" activity of the fungus Phoma exigua and fungi from the genus Fusarium;
- Fusarium-bacterial (dry or wet - depends on storage conditions). They are provoked by the combined "labor" of fungi from the genus Fusarium (Fusarium coeruleum, Fusarium c u lmorum, Fusarium sambucinum, Fusarium semi t ectum, Fusarium solani, etc.) and bacteria from the genera Bacillus, Pectobacterium, Pseudomonas.
Sharp fluctuations in temperature in storage "encourage" the development of wet bacterial rot. In the upper layer (25-30 centimeters thick) of the pile, the relative humidity of the air is usually increased, which also favors the acceleration of the destructive process. If it reaches 90% and the temperature does not fall below 20-25° C , - the tubers will rot in a week.
Symptoms of wet bacterial rot of potatoes.
Spots are observed on the skin of the tuber - soft and moist to the touch. (And sometimes it doesn't show anything.)
His flesh gradually:
Emits an unpleasant (albeit weak) stench;
- acquires a dark brown color, sometimes pink. If not the entire volume of the tuber is affected, then the junction with healthy tissue is “marked” on the cut with a distinct brown border;
- becomes soft, raw and viscous, that is, it turns into mucus (slurry).
A liquid is released from a rotting tuber - and neighboring potatoes that come into contact with it also begin to fall ill. Thus, a focus of "infection" is formed. It may not be the only one in this heap if the rules for laying the crop were violated.
Self-heating of the hearth is associated with rotting tubers, from which it “flares up” even more.
Measures for the control and prevention of wet bacterial rot of potatoes.
1. The “State Register of Breeding Achievements Approved for Use” in Russia as of January 31, 2013 contains about 350 potato varieties out of about 5 thousand that exist today in the world. Therefore, there is ample opportunity to choose a variety that is more resistant to this disease - for example, "Pigeon".
2. Based on information about the optimal harvesting time, time it for dry weather (not necessarily bright sunny, but warm). In particular, "Pigeon" belongs to the middle-late varieties, that is, you can start digging up its tubers 95-110 days after planting.
2a. All harvesting operations should be carried out with care, minimizing the number of injuries caused to tubers by tools, equipment and/or machinery.
2b. After removing the tubers from the ground, arrange them to dry in the open - and in no case leave them there overnight if it is expected to be cool.
3. Carefully sort the crop, while cleaning it from soil residues and plant debris (tops, straw).
4. For industrial scale, a special technology for storing potatoes has been developed, which can also be followed in the private sector. It includes 4 phases:
4a) the healing period, when the lesions heal and infected tubers appear. Lasts 15-18 days. Temperature from 18-20° C gradually reduce by the end of this period to 10-12 ° C . Ventilation is also necessary so that the surfaces of the tubers become completely dry. Its mode is determined by their initial state. Optimal is a 40-50-minute session repeated 5-6 times a day at a flow rate of 100-150 cubic meters of air per 1 hour per 1 ton of "bulb";
4b) cooling period. The recommended rate of temperature decrease is 0.5°C per day, but if there were a lot of rejected tubers, then it is better to double it. Final target - 3-4°C for seed, 4-6° C for table potatoes;
4c) the main phase, during which it is not necessary to change the air parameters;
4d) rise in temperature up to 8-15° C before unloading from storage for planting (or for sale). Reduce ventilation or stop altogether, due to which a leisurely self-heating of the collar should occur.
5. It is impossible to abuse the bulkhead, because chilled tubers are easily damaged. However, it is needed in order to timely identify and eliminate foci of the disease.
5a. The first one is advised to be done 4-6 weeks after laying, the next ones - based on the results of a visual-manual check of the top layer of the collar. If you need to urgently sort out the entire mass of the crop - do not neglect the subsequent drying.
5 B. It is useful to accompany the bulkhead with dusting of healthy tubers, for which dry ash from burning firewood or finely ground phosphorite flour is used (particle sizes up to 0.18 mm). Estimated consumption - 10 kilograms per 1 ton of potatoes.
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