A fungal disease that can affect many types of plants.

With the defeat of pumpkin crops on stems, leaf petioles and fruits, the tissue softens and rots, becoming covered with a white dense coating (mycelium). Subsequently, the mycelium becomes denser, first white and then black formations (sclerotia) the size of a pea develop, wintering on plant debris. The disease progresses with high humidity in greenhouses.

White rot is a common cabbage disease, especially in heavy loamy soils. During the growing season of cabbage, the root neck and lower leaves are mainly infected. Affected tissues become discolored, become watery, covered with cotton-like white mycelium. By autumn, the mycelium thickens, turning into black sclerotia of various shapes.

White rot is especially harmful during the storage period of cabbage. The defeat usually begins with the outer leaves while still in the field, especially in rainy weather. Leaves rot and become slimy. An abundant mycelium develops between the leaves, from which numerous sclerotia are subsequently formed. On heads of cabbage, the fungus does not develop sporulation. The disease is easily transmitted to neighboring heads. The development of white rot in storage is favored by violation of the storage regime and high humidity.

White rot is also the cause of significant losses of carrots during storage and the death of seed plants during the growing season. Of the other root crops, it affects parsley and celery. On the surface of the root crops, a white mycelium is formed, on which black sclerotia of the fungus subsequently form. The fabric softens, turns brown, the roots completely rot.

Onions and garlic also suffer from white rot. Plants are affected both during the growing season and during storage. When infected in the field in young plants, the leaves turn yellow, starting from the top, and die off. Plants quickly wither and die. A white fluffy mycelium forms on the roots and scales of the bulbs, the garlic cloves become watery and rot. Small punctate sclerotia appear on the affected tissue. The fungus develops well at a temperature of 10-20 °. It overwinters as sclerotia in the soil and in storage on infected bulbs.

White rot is dangerous for tomatoes. The disease manifests itself sharply if in greenhouses during the planting of tomato seedlings in the ground, low air temperature (12-15 °) and high humidity (95%). The characteristic signs of white rot of tomato are the withering of the top of the plant and the decay of the lower part of the stem. The basal part of the stem softens, sometimes covered with a white flaky bloom. Large black sclerotia are visible on the cut of the stem. Sometimes they are formed on the surface of the stem. As a rule, white rot appears in foci and causes attacks on a small number of plants.

When a cucumber is affected, the disease can develop on all parts of the plant - roots, stems, petioles, leaves and fruits. When the terrestrial organs are affected, the tissues become soft, slightly mucilaginous, covered with a dense white mycelium, in which black sclerotia subsequently form. Plants wither, leaves lose turgor, dry up.

The disease is especially harmful where as a result of a permanent culture. cucumbers, the infection accumulates in the soil, as well as in greenhouses where there is no heating and poor ventilation. The first foci of the disease usually appear with a sharp drop in air temperature to 14-16 ° and high relative humidity (95-98%). The causative agent of white rot is transmitted through the air with the help of detached pieces of mycelium, and is also transferred mechanically (on hands and tools).

White rot is dangerous for peas and beans. The stems and especially the beans of these crops are affected. Characteristic signs of the disease are softening and whitening of the affected tissues, the formation of abundant white mycelium on the surface and inside the stem and beans. Later, rather large black sclerotia of the fungus form on it. The infection can accumulate from year to year in the soil in the form of sclerotia, especially with frequent cultivation on the same plot of crops affected by white rot: cucumber, carrot, lettuce, parsley, etc. The causative agent of white rot is transmitted with pea and bean seeds.

Control measures

When pumpkin crops are affected by white rot, it is necessary to maintain an optimal hydrothermal regime in the greenhouse; sprinkle the affected tissue with crushed coal or chalk; coat the affected areas with a pink paste (chalk mixed with potassium permanganate with the addition of water); cut out the diseased part with the capture of the healthy part; In the evening, water the plants with warm water.

It is also recommended to use foliar top dressing: zinc sulfate - 1 g, copper sulfate - 2 g, urea - 10 g per 10 liters of water; carefully remove all plant debris with the top 2-3 cm layer of soil; reduce air humidity in a greenhouse or in a greenhouse by periodic ventilation.

With the defeat of cabbage, the measures to combat the disease are the same as with gray rot. Late sowing of seeds and planting seedlings intended for seed purposes, cleaning of mother liquors before frost, thorough cleaning and disinfection of storage facilities, compliance with optimal storage conditions (temperature from 0 to -1 ° C), cleaning of affected heads with mandatory waste disposal contribute to a decrease in plant damage. , careful selection of only healthy testicles.

Particular attention should be paid to the alternation of crops in the crop rotation. The predecessors of cabbage should not be carrots, cucumbers, lupins, beans, which are also affected by the causative agent of this disease.

With the defeat of root crops - carrots, parsley, celery - a set of measures is recommended. It includes the following: observance of the correct crop rotation with the return of root crops to the former field no earlier than in 3-4 years and the exclusion from the predecessors of crops affected by white and gray rot (tomatoes, cucumbers, cabbage); selection of healthy queen cells before storage and planting in the field, spatial isolation between the culture of the first and second years; thermal disinfection of seeds at a temperature of 45-50°C for 30 minutes; spraying plants of the second year with 1% Bordeaux liquid, starting from the moment the first signs of disease appear. Storage of root crops should be carried out at a temperature of 1-2 ° and air humidity of 80-85%.

Measures to combat white rot and onions and garlic include the same techniques as with neck rot. First of all, you need to get healthy planting material. Harvesting of the bulbs should be carried out during their full ripening, followed by drying the bulbs in sunny weather in an open place in one layer, in wet weather - first under a canopy, and then for 7-10 days indoors with air heating up to 26-35 °. When cutting onions, leave a neck 3-6 cm long. It is recommended to store onions under optimal conditions: food - at a temperature of 1-3 ° and relative humidity of 75-80%, uterine bulbs - at 2-5 ° and 70-80%, sets – at 18-20° and 60-70%.

When a tomato is damaged, thermal disinfection of the soil is carried out, diseased plants and fruits are destroyed. Temperature and humidity in greenhouses should be optimal.

In case of damage to the cucumber, the greenhouse soil is disinfected, the affected parts of the plants are removed. The optimum air temperature in the greenhouse should be at least 18 °. You can not grow cucumber in the soil where parsley and celery used to grow.

The main measures that reduce the harmfulness of white rot for peas and beans are crop rotation, removal of diseased plants from the field, especially in seed plots, optimal sowing dates and pre-sowing seed dressing.

Simple measures will help prevent the death of your crop due to white rot. Vegetables will not get sick during the growing season and storage.

How does white rot appear on various plants?

To understand that this disease really appeared on your plantings, you need to know how it looks on various plants. If cabbage grows on heavy loamy soils, then this disease is likely to appear on it. In this case, its lower leaves and root neck are mainly affected. The tissues of plants on which white rot has settled become watery and discolored. The fungus spreads in the form of a white coating that looks like wet cotton wool.

Especially white rot rages in cold rainy weather. Having settled on one plant, under suitable conditions, the fungus quickly infects neighboring heads of cabbage. The disease can appear not only during the growing season, but also during storage, especially if there is poor ventilation and high humidity in the basement, cellar.

How white rot appears on pumpkin, the photos demonstrate eloquently. At the same time, the tissues of the stems, leaves, fruits are covered with a white coating and rot. Then the disease passes into the next stage, then the white neoplasms turn black, they overwinter on unharvested plant debris and the next year can damage new crops planted in this place. Since the fungus loves high humidity, for the most part it progresses in greenhouses, where there is poor ventilation.

High humidity in the greenhouse is the main reason for the spread of white rot on tomatoes. The low air temperature also contributes to this. To recognize the disease, it is enough to look at the tops of the plants, if they have withered, then this should alert the gardener. Other signs of the appearance of white rot are the decay of the lower part of the stems, their softening. Sometimes a white coating appears here.

This disease can also affect garlic and onions. If this happens during the growing season, then the leaves of the plant turn yellow prematurely, starting from the top, and then die off. The fungus penetrates to the roots and covers them with a fluffy white mycelium. Due to the harmful effects of the disease, garlic cloves, bulbs become watery and rot. If the storage is not disinfected, after laying a new crop there, it can be affected by a fungus left over from last year.

Of the root crops, white rot loves to settle on carrots, celery, and parsley. At the same time, a white mycelium is formed on the surface of the root crops, and subsequently black sclerotia of the fungus appear on it. This leads to softening of the tissue, and as a result, the vegetables completely rot.

Mycelia on beans and peas like to settle on the surface of the pods, penetrate into them and infect, gradually turning into black fungus sclerotia.

Prevention of white rot

It consists in cleaning plant residues, airing greenhouses. If there is no high humidity here, then the risk of developing the disease will decrease significantly. Sometimes indoor plants can also be affected by this scourge, as spores are also transmitted by wind. Therefore, if rainy weather has set in, high humidity, then it is better to bring flower pots into the room if they are on an open veranda, balcony, or garden. Before planting a houseplant in a pot, it is better to ignite the soil in the oven or microwave.
In order for the plants to resist the fungus, you need to periodically spray them with a nutrient solution. To do this, dilute in 5 liters of water:

• 5 grams of urea;
• 1 gram of copper sulfate;
• 0.5 grams of zinc sulfate.

If you notice that a part of the plant has just begun to be attacked by a fungus, sprinkle it with crushed coal. You can make a paste by pouring a little potassium permanganate into the chalk, you need to add water so that when you mix it, you get a mass similar in consistency to liquid cottage cheese. It also lubricates the parts of the plant attacked by the fungus. If the disease has spread greatly, then it is advisable to cut out the diseased area, and then sprinkle the cut points with chalk or this suspension.

Treatment of white rot on cucumbers

If you notice the first signs of disease in the greenhouse, stop watering and fertilizing the plants for a week to reduce the humidity in the air. Then you need to dilute 10 g of the Oxyhom preparation in 5 liters of water or 1 ampoule of the Topaz preparation in 10 liters of water and spray the cucumber lashes.

After that, it is necessary to ventilate the greenhouse. It is better to carry out such treatment early in the morning so that during the day the air temperature does not fall below + 20 ° C, and at night - + 18 ° C. If at night the temperature drops below this mark, then the lashes need additional cover with non-woven material or film. A week later, the treatment with Topaz is repeated.

If you prefer folk remedies, then spray the plants with whey or prepare a solution consisting of:

• 3.5 liters of water;
• 1.5 liters of serum;
• 0.5 tsp copper sulfate.

When you collect the last crop, spill the bed with a solution prepared from 5 liters of water and 25 g of copper sulfate. You can shed the soil without removing the plants, and after a day, pull them out right with the roots and burn them.

Resistant cucumber hybrids can resist this disease. Where you plan to grow pumpkins, do not plant celery and parsley 3 years before, which often have white rot.

Treatment of the disease on root crops

In order to prevent the defeat of white rot of root crops (carrots, potatoes, beets, turnips, celery, radishes), it is necessary to observe crop rotation, use only healthy mother liquors for planting. And if you sow plants with seeds, then you must first disinfect them in water at + 45 ° C for 5 minutes, and then lower them into cool water for 2 minutes.

Root crops should be stored in a cool place at + 3 ° C and monitor the humidity of the air, it should not be higher than 85%.

To prevent white rot damage to garlic and onions, use only healthy planting material. Harvest the bulbs when they are fully ripe. Then dry them well. After that, cut off the roots, leaving 3-5 mm and dried feathers, leaving a neck 5-7 cm long. Onions and garlic should be stored at + 1- + 5 ° С, relative humidity of 80 percent or less.

Learn more about how to cure cucumbers from white rot in this video:

Cucumber farming technology today is known to the subtleties of any experienced summer resident. This culture is easy to grow, responsive, and the main problem is its protection from numerous fungal diseases. One of them is white rot. Its causes, symptoms and treatment will be discussed in the article.

Symptoms of white rot of cucumber

White rot is difficult to confuse with any other disease. (See also the article about ⇒ "). Its signs are characteristic and make up the following set of symptoms:

• multiple white spots appear on different parts of the plant;
• the affected parts become watery, look rotten;
• foci of infection are covered with a white flaky coating;
• leaves and tops of shoots wither, die off;
• black sclerotia develop on the affected parts, visible on the cut.

White rot affects all parts of the cucumber bush - stems, leaves, roots, mustaches, fruits. With inadequate treatment or its absence, the plant quickly dies, and the disease spreads to neighboring bushes.

The causative agent of the disease and the conditions for the development of white rot

White rot is an infectious disease. It is caused by a pathogenic marsupial fungus - sclerotinia. Spores of sclerotinia, penetrating into the tissues of the plant, quickly germinate and form a mycelium - the very characteristic cotton-like coating. As the fungus grows, fruiting bodies full of new spores develop. Spreading, they are able to infect the entire cucumber plantation in a short time.

Cucumbers grown in greenhouses, unfortunately, are also not protected from white rot. Poor ventilation, condensation, day and night temperature fluctuations favor the development of the disease.

The spread of sclerotinia is often facilitated by mistakes made by gardeners themselves:

• Thickened planting and cultivation of cucumbers in spreading.

In such a situation, it is very difficult to notice a diseased bush in time and take action. The fungus easily infects neighboring plants, which is favored by high humidity between the intertwined stems and leaves.

• No formative pruning.

When growing varieties with active branching without proper pruning and pinching, plantings quickly turn into a jungle, thicken, and the problem described above arises.

• Using a dirty tool.

Spores of the fungus are carried on garden knives, scissors. All inventory must be clean. The primary infection of the beds occurs by infecting the soil, so shovels, choppers, flat cutters also need regular cleaning and disinfection.

Infection of cucumber plants with sclerotinia occurs through various mechanical damage to the stems. Therefore, the bushes should be handled as carefully as possible, and pruning should be done with sterile scissors.

Treatment of white rot of cucumber with the help of agrochemistry

Fungicides containing copper demonstrate the greatest effectiveness in the fight against white rot of cucumber. Systemic preparations based on other active substances can also help. According to the recommendations, at the first signs of the disease, one of the following drugs should be used:

A drug	Active substance	Mode of application
"HOM"	Copper oxychloride	Dilute 40 g in 10 liters of water and spray the bushes twice with an interval of 10-14 days.
"Abiga Peak"	Copper oxychloride	Dilute 50 ml in 10 liters of water and spray the bushes three times within 20 days.
"Ordan"	Copper oxychloride and cymoxanil	Dilute 25 g in 10 liters of water and spray the bushes 2-3 times with an interval of 10-14 days.
"Acrobat MC"	Dimethomorph and Mancozeb	Dilute 20 g in 5 liters of water and treat the bushes twice with an interval of 10 days.
"Ridomil Gold"	Mefenoxam and Mancozeb	Dilute 25 g in 10 liters of water and spray the bushes 3 times with an interval of 7 days.

Preparations based on copper oxychloride are more preferable for combating white rot, since microorganisms cannot develop resistance to them. In addition, such agents do not penetrate deep into the tissues of the plant, so the active substance does not accumulate in the fruits.

🎥 Video advice from Oktyabrina Ganichkina "Rot in cucumbers, how to get rid of: tips."

Ways to get rid of root rot from Oktyabrina Ganichkina, an expert and experienced gardener.⇓

https://youtu.be/ltLRDcFr6G8

Tip #1 Some preparations containing copper do not adhere well to the leaves and are easily washed off by the first rain. According to the experience of some gardeners, this drawback can be corrected by adding a little milk to the prepared solution - about 1% of the volume of the solution.

Folk ways to deal with white rot

If white rot is found on cucumbers, and a suitable preparation is not at hand, you can try to cope with the infection with one of the folk remedies:

Means	Cooking	Mode of application
Iodine with milk and soap	For 1 liter of milk or whey, add 1 tablespoon of grated laundry soap and 30 drops of iodine alcohol tincture. Dilute the product with water up to 10 liters.	Copiously spray the entire ground part of the bush.
Soap and soda solution	In 10 liters of water, dissolve 10 tablespoons of soda and a small piece of laundry soap.	Spray cucumber bushes.
Manganese-soda solution	Dissolve 8 tablespoons of soda and the same number of potassium permanganate crystals in 10 liters of water so that the solution acquires a pink tint. Add 1 tablespoon of grated laundry soap.	Spray cucumber bushes.
Ash-chalk ointment	Mix equal parts wood ash and crushed chalk. Add some water to make a thick paste.	Cut off the shoots and leaves affected by the fungus and coat the sections and areas around them with a brush.

Folk remedies can help only in the early stages of the disease, but even in this case, a cure is not guaranteed. Plants need to be closely monitored. If, after two treatments with home formulations, the infection continues to develop, it is better not to risk it and urgently apply a preparation containing copper.

Tip #2 After treatment with chemical fungicides or home formulations, it is necessary to give cucumbers phosphorus-potassium top dressing. Phosphorus and potassium will help plant tissues acquire sufficient strength and increase resistance to infection. Nitrogen supplements should be stopped.

Biological method of combating white rot of cucumber

On the basis of strains of this fungus, the preparation "Trichodermin" was developed. It is available in the form of tablets, powder or solution. You can use it in different ways:

• Prevention of white rot and other fungal diseases of cucumbers.

A solution is prepared from 5 g of Trichodermin powder and 5 liters of water and poured into the hole before planting seedlings or before sowing.

• Treatment of white rot and other fungal diseases of cucumbers.

All affected parts are cut from the plant to healthy tissue. 250 ml of liquid "Trichodermin" is diluted in 10 liters of water, all bushes are plentifully sprayed. The soil is shed with a solution prepared from 5 g of Trichodermin powder and 5 liters of water. The treatment is repeated after 3-4 days, and then after 2 weeks.

The drug is safe for bees and humans, does not harm the environment. You can collect and eat greens from the treated bush already 3 days after spraying on the leaf.

White rot of greenhouse cucumbers: greenhouse processing methods

The insidiousness of white rot lies in the fact that sclerotia spores remain in the soil for an exceptionally long time. According to some reports, they remain viable for ten years. Therefore, when greenhouse cucumbers are affected by this fungus, the question of soil disinfection after harvesting becomes acute.

You can disinfect the greenhouse as follows:

• remove all plant debris;
• spill the soil with a 3% solution of copper sulfate;
• wash the walls of the greenhouse and racks, wipe them with a solution of copper sulfate;
• fumigate the greenhouse with a sulfur checker and ventilate thoroughly;
• dig up the soil and sow the beds with white mustard, leaving the seedlings to winter;
• in the spring, dig up the beds and spill them with a solution of the Baikal EM-1 preparation 2 weeks before planting seedlings of cucumbers.

When fumigating a greenhouse with a sulfur bomb, one must remember that sulfur dioxide has a destructive effect on metal. Therefore, if there are areas of corrosion or other defects in the metal frame, this step will have to be skipped.

Varieties of cucumbers resistant to white rot

If in the previous season the cucumbers on the site suffered from sclerotinia, in subsequent years it is worth planting varieties that are resistant to this pathogen. You can pay attention to the following ones:

The popular Connie F1 cucumber also shows sufficient resistance to white rot, despite the fact that this disease is not indicated in the description of the hybrid of this disease.

Prevention of white rot of cucumber

The sum of preventive measures to combat white rot of cucumber is as follows:

• compliance with the correct planting scheme;
• timely and correct formation of the bush and its garter;
• compliance with the temperature regime and the prevention of waterlogging;
• use of clean equipment when caring for plants;
• competent top dressing, without excess nitrogen fertilizers;
• soil care, maintaining its ecological balance, the use of beneficial microorganisms;
• preventive treatments with copper-containing or biological preparations;
  disinfection of greenhouses after harvesting.

Also, when growing cucumbers, it is important to remember the principles of crop rotation and not plant them in the same place for several years in a row.

Topical questions about the treatment of white rot

Question number 1. Are there plants that can be planted next to cucumbers to protect against white rot?

Unfortunately, it will not be possible to protect cucumbers from sclerotinia by planting suitable neighbors. This pathogen has a wide specialization and affects a large number of plant species.

Question number 2. How long does it take to cure white rot on cucumbers?

In the case of timely detection of the disease and the use of the correct tactics, you can get rid of white rot in 3-7 days. If the disease has already severely affected the cucumber bush, treatment may be futile.

Question number 3. Is white rot of cucumber contagious to other plants and humans?

Sclerotinia harms a person only because it destroys the crop. It can also spread to other vegetable crops. All pumpkin and melons, as well as beans, onions and garlic, tomatoes, peppers, grapes and sunflowers suffer from white rot. Green crops can also be affected by sclerotinia, so plant them carefully to compact cucumbers. White rot is also observed on ornamental plants - peonies, violets, bulbs.

Question number 4. If a cucumber bush dies from white rot, does it make sense to treat it or is it better to throw it away?

If the infection is detected at a late stage, it is, of course, better to dig up and burn the diseased bush. The earth from the hole where he sat should be thrown away, the hole should be poured with a solution of manganese or "Fitosporin-M" and pour clean soil. Treat the rest of the cucumber bushes with a fungicide.

Sclerotinia on carrots

When using a film to protect the soil, the disease manifests itself more often. Absolutely all parts of plants are subject to defeat - fruits, mustaches, petioles, stems. The most dangerous manifestation of white rot on the stem is when the root part is affected. In the affected area, the stem looks moist, rotten and covered with mycelium, which is very similar to cotton wool. The leaves gradually fall, turn yellow, after which the stem is refracted and the plant dies.

On fruits, white rot appears as a white bloom, the fruits soften and become flabby. With the continuation of the disease, black spots, about the size of a pea, form in the places of damage.

The fungus has 2 stages of growth, which are determined by external signs. The first stage is the formation of sclerotia, they are spherical black in color. The second stage is the formation of fruiting bodies, their shape in the form of a saucer or glass. Cylindrical bags develop inside the fruiting bodies, in which ascospores ripen. This fungus does not produce conidia. Sclerotia overwinter, remaining in the soil for up to 10 years, while the ability to germinate is preserved all this time.

What is dangerous

With the development of the disease, the plants die. Fruits and roots rot and become unfit for consumption

What caused

The causative agent of the disease is the omnivorous marsupial fungus Sclerotinia sclerotiorum.

When it appears

At a temperature of 10-15 degrees Celsius above zero.

What contributes

The spread of sclerotinia is facilitated by prolonged rains and sudden changes in temperature. The risk of disease also increases with thickened crops, the presence of a large number of weeds.

How it spreads

The spread of the disease occurs with the help of infected soil, with planting material. Sclerotia can be carried by the wind over long distances.

Prevention

• If a disease is detected, the affected plants must be isolated and burned;
• timely destruction of weeds;
• once every 10 days inspection of crops;
• competent observance of crop rotation: the basic rule is that the cultivation of crops in one place is repeated no earlier than after 3 years;
• acidic soils need to be limed and it is desirable to abandon the application of phosphorus fertilizers.

Fighting methods

• Potassium fertilization will reduce the risk of carrot infestation. Before storing, treat the uterine roots of TMTD in proportions of 6-8 liters of working solution per 10 liters of water. The amount obtained is calculated per ton of queen cells;
• the biological method of control consists in the use of a culture of the fungus Trichoderma lignorum (trichodermin-3), it must first be propagated on heated peat, it is added to the mixture for seedlings and when planting, per 1 sq. meter of soil consumption 150-400 g;
• complete elimination of infected plants, after that, treat the area with powders, you can use fluff lime or crushed charcoal;
• copper-containing fungicides are effective: 1% Bordeaux liquid, Profit Gold, Ridomil GOLD MC, Ordan, Oxyhom, Khom, Acrobat MC, Abiga-peak, Previkur. Apply in accordance with the instructions.