Rot on tomatoes is gray, white and black: what are the differences from leaf spot, how to fight, how to treat tomato fruits in a greenhouse, how to get rid of it on seedlings?

Every gardener eagerly awaits the ripening of his harvest.
However, hardworking summer residents do not always receive a well-deserved reward. One of the unpleasant situations that occurs with the harvest is the appearance of rot on the plants. As a result, tomatoes stop growing and die. To prevent this from happening, it is necessary to follow some precautions and rules of agricultural technology.

What it is?

Rot is considered a dangerous fungal disease that affects many vegetables, including tomatoes. The following types of rot exist:

Gray mold is caused by the pathogen Botrytis cinerea Pers.
White rot is caused by the pathogen Sclerotinia sclerotiorum.
The causative agent of black rot is the fungus Diplodina destructiva Petr.

Rot on tomatoes, as a rule, occurs due to non-compliance with agricultural technology conditions, lack of soil disinfection and proper watering regime.

Approximate scheme of preventive measures against gray rot

In order to minimize the risk of occurrence and consequences of gray rot, treatment of tomatoes and shelters where they grow must be timely.

Approximate treatment plan:

in spring - soil treatment with special preparations Fitosporin, Glyokladin;
early summer - coating tomato bushes if there are foci of disease on them;
August - treatment of plants with fungicides (if gray rot appears en masse on the plantings);
September – repeated treatment of plantings with preparations.

Important! After harvesting the fruits, it is necessary to disinfest the greenhouses, treat the soil, and replace it.

Gray rot, which is dangerous for tomatoes, can be prevented with the help of preventive measures and compliance with agricultural practices. In case of infection of plants, special preparations are used, strictly observing dosages.

Reasons for appearance

There are many reasons for rot on fruits. Most often, the main ones are distinguished:

Overmoistening of the soil.
Lack of soil disinfection.
Lack of vitamins, especially calcium.
Excess of nitrogen, potassium, salts or magnesium in the soil.
Lack of the required amount of sunlight.
Traumatization of the root system.
High air humidity.
Using untested seeds.

Important: Lack of moisture in the soil during the ovary period contributes to the formation of rot. Due to the lack of moisture, the plant begins to actively seek it and takes it from the fruits, and therefore the tomatoes begin to rot. However, excess moisture can also cause rot.

Why tomatoes suffer from blossom end rot: causes

The main cause of blossom end rot on tomatoes is insufficient watering.
There can be many reasons for blossom end rot on tomatoes:

When tomatoes begin to set, they need to be well watered, but with little or no watering , the fruits do not have enough moisture. Since the plant takes most of the incoming moisture onto itself and can also pull it from the fruits, then gray spots of rot appear on the tops of the set tomatoes.
After watering the soil has become compacted , a hard crust of soil has formed, and water and air cannot reach the roots.
If you water your tomatoes often and in small portions, then there is also not enough moisture , and blossom end rot may form.
If you often feed your tomatoes with manure, then there may be an excess of nitrogen in the soil , which cannot be absorbed by the tomatoes, and blossom end rot appears on them.
If it is very hot , tomatoes may stop absorbing calcium from the soil, and then blossom end rot will also appear.
If the soil in your area is too acidic or salty , then calcium is poorly absorbed by tomatoes, and blossom end rot appears.
If tomatoes are lying on the ground , they may begin to rot as a result of bacteria from the wet soil .

Signs of defeat

A disease such as anthracnose is often confused with tomato rot. In this case, the leaves become covered with a layer of pinkish mold, which is not observed with the development of any type of rot. The only common symptom of these diseases is black-brown spots on the fruits. However, distinguishing these diseases is not difficult.

Symptoms of gray mold can be confused with late blight. In the case of this disease, round, watery spots appear on the fruits, and gray mold develops on the leaves and stems. The spots on the fruit increase in size and a brown liquid is released. When diseased with gray mold, plants become covered with a fluffy coating, which is a hallmark of the disease.

Chemicals to combat gray mold

Fungicides are used to coat plants damaged by the gray rot fungus, and continuous spraying is used only in case of massive lesions of tomatoes.

For minor infections, it is permissible to use the following compounds:

Ditan M-45;
Bordeaux mixture;
Profit;
Integral;
Speed;
Fundazol.

Treating tomatoes with Hom, Oksikh, and Abiga-Pik gives a good effect.

To destroy pathogenic fungi, the drug Euparen is used. This is a contact fungicide, available in powder form. The drug is based on dichlorofuanide, which has a detrimental effect on fungal sporulation.

The drug is diluted in water (a 2% solution is used on tomatoes), following the dosage according to the instructions.

Of the systemic contact agents on tomatoes, the use of Ordan, Previkur, Acrobat MC is shown.

To coat plants (stems, leaves) affected by gray mold, use a special paste mixture.

Pasta recipe:

300 grams of CMC glue;
30 grams of any fungicide;
a bucket of water.

The glue and fungicide are mixed in water until completely dissolved, then chalk is added to form a paste. Apply the mixture to the spots, while also including healthy tissue around the affected area. After 10-12 days, the coating is repeated.

Types, their descriptions and photos

Among the diseases of tomatoes, there are several types of rot. These include gray, white and black rot. Each type of rot is caused by a different pathogen and manifests itself differently.

Gray

The disease affects fruits growing both in open ground and in greenhouse conditions. The cause of gray rot is considered to be high humidity and excessive amounts of nitrogen fertilizers.

White

The primary sources of the disease are compost and soil, so infected plants must be destroyed and cannot be composted. The causes of white rot are undisinfected soil. Its development is promoted by high humidity and low air temperature (below 18ºС) during planting.

Black

The causative agent of the disease penetrates into overripe fruits through the cracks formed. The cause of the disease is excessive air humidity.

Biology and chemistry against rot fungus

In addition to agrotechnical measures, biological and chemical measures are widely used in the fight against fungus and in the treatment of tomatoes from gray rot.

Biological techniques

They involve the treatment of tomato stems, which need to be treated with a trichodermin suspension. This is done after cutting off the affected foliage, which stops the appearance of secondary fungal outbreaks. Together with trichodermin, it helps to fight and shows itself well as a biological protection against gray rot on tomatoes, gliocladin, which is applied to wet areas. Such labor-intensive methods of combating gray mold show good results with long-term effectiveness. Using these biological suspensions, you can spray tomato bushes, doing this during the daytime, allowing the plant to dry out before the cool of the evening.

Chemicals

Prevention and treatment of the disease can be done using chemicals - fungicides. During the growing season, when signs of disease are detected on tomatoes, the stems and leaves of the plants are coated with fungicidal preparations. In advanced cases, it is recommended to spray tomato bushes with fungicides in a continuous manner, which prevent the intensive spread of the fungus in the greenhouse and allow you to save the crop.

Reviews from gardeners advise adhering to the schedule for treating tomatoes with fungicides:

in May, make sure to coat and spray the identified affected areas with the preparations,
repeat treatment after 2 weeks,
in June - July, apply coatings to the damaged areas; in the second half of August, when the disease spreads, treat the tomatoes with preparations in a continuous manner,
re-process in early September.

Preventive protection of tomatoes also involves treating the soil with preparations, steaming the substrates, and disinfesting greenhouse structures.

How do diseases develop and why are they dangerous?

Gray rot. The disease is transmitted from plant to plant. Affected tomatoes quickly wither and die. Externally, the disease manifests itself as follows:
Formation of a characteristic fluffy coating.
Leaf spotting.
Damage to the plant stem.
White rot. Most often, this type of rot forms on damaged areas of the fruit and usually appears during storage of the crop. External signs of the disease:
Fruits covered with white coating.
Black rot. Black weeping spots appear on the fruits, most often near the stalk or in places of damage. The affected tissue softens, the spots become more numerous and the plant dies.

The first signs of the appearance of gray blossom end rot on tomatoes: description, photo

At the beginning of the disease with blossom end rot, the tomato is flattened on the crown, and then a gray spot appears.
The fact that tomatoes are sick with blossom end rot can be seen even on green tomatoes. The first signs of the disease:

The tomato seems to be flattened
Watery spots on a green tomato, darker than the whole tomato
After some time, the dark green spot on the tomato turns into a brown, brownish or dark gray spot , and then a black spot, the tomato wrinkles in this place, the branch withers, and the tomato falls off.

What should I do to get rid of it?

So what is the most effective way to combat rot on tomatoes? There are basic rules that, if followed, will help you save your harvest. In addition, it is better to choose the varieties that are most resistant to these diseases and do not forget about crop rotation.

How to fight with agrotechnical methods?

Compliance with agricultural practices is an excellent prevention of rot in tomatoes. It is enough to adhere to the following rules to ensure that the plants remain healthy and strong:

Follow a proper watering schedule. Water the plants regularly, but do not overwater them.
Mulch the soil. This will help distribute moisture evenly and maintain the necessary looseness of the soil.
It is advisable to cut out infected areas of the plant with a knife in dry and sunny weather.
Remove affected fruit regularly.
Ventilate the greenhouse often.
Do not allow water to get on the leaves of the plant when watering.
It is advisable to plant mustard, calendula or marigolds in the infected area. These plants secrete special substances that prevent rot from developing.

How to treat with folk remedies?

Gardeners often use folk remedies to combat rot. Here is one of the most effective:

The soil can be shed with a solution containing calcium. To prepare this fertilizer, dissolve 2 tablespoons of chalk in 10 liters of water. Fertilize the soil with this mixture, observing moderation. This method helps restore the required level of calcium in the soil.
You can spray plants with calcium for the same purpose. Spraying of tomatoes is carried out before they begin to flower, several times in the first week after transplanting into the ground. To prepare the solution you will need 40g of calcium per 10 liters of water.

How to treat with chemicals and fungicides?

An important role in the fight against rot on tomatoes is played by disinfection of diseased plants with disinfectants:

Coating the plant with fungicide. The timing and frequency of application of fungicides for tomatoes are indicated in the instructions for the specific product.
Here is one recipe for coating: stir 300-330 grams in 10 liters of water. CMC glue, as well as 20-50 gr. fungicide. Bring the mixture to a paste-like consistency using chalk. The rotten spots are coated so as to cover about 3 cm of healthy tissue. It is recommended to use such fungicides as Topaz (4880 rubles per 1 liter), Oksikhom (60 rubles per 10 g), Kuproskat (4830 rubles per 10 liters).
Treatment with Bordeaux mixture. The procedure for treating infected tomatoes is carried out three times with a break of up to 10 days. Gardeners recommend carrying out no more than 4 such procedures per season. If the disease has spread to the seedlings, then they must be treated with Bordeaux mixture 10-14 days before planting in a greenhouse or soil. The mixture is prepared according to the instructions:
Lime mortar is prepared. 140-150 g of lime (170 rubles for 20 kg) are stirred in 1 liter. water.
4 liters of cold water are poured into another container, then lime mortar is poured in. Everything is thoroughly mixed and filtered through a non-metallic sieve or cheesecloth.
The vitriol solution is carefully poured into the lime solution. The resulting mixture is thoroughly mixed.

We offer you to watch a video about the prevention of gray rot:

Biological drugs for treatment

Biological preparations cope quite effectively with rot. To combat it, natural preparations such as:

Agate 25K.
Gamair.
Alirin-B.
Fitosporin-M.

Biological preparations are considered safe for humans and non-toxic for bees.

Tilling the soil after infected tomatoes

After treating damaged plants, it is also necessary to treat the area to avoid re-infestation.

Destroy all remnants.

Considering that black sclerotia of fungal spores accumulate in plant debris by the end of the growing season, they must be harvested carefully and completely disposed of. Plant residues showing signs of disease should not be used in compost heaps.

Land cultivation.

Includes fumigation of soils, substrates for greenhouses, steaming of soils. To disinfect the soil, the soil is spilled with a solution of one of the drugs (Alirin, Glyokladin, Barrier and others), which have a detrimental effect on surviving fungal spores.

Deep plowing.

In autumn, after removing plant residues and disinfecting the soil, dolomite flour or chalk is added and the soil is dug deep.

In protected ground, it is mandatory to disinfect structures, glazing, tools and materials. Fumigation can be used by burning sulfur briquettes.

Prevention measures

There are certain rules that can help avoid rot and ensure the ripening of healthy and beautiful tomatoes. Prevention of this disease is as follows:

Never allow plants to become dehydrated or over-watered.
Maintain the salt balance of the soil. Soil salinity causes insufficient moisture supply for plants, which causes calcium deficiency. Do not get carried away with feeding with magnesium and potassium.
Spray the tomatoes with a solution containing calcium.
Maintain a temperature that is comfortable for the tomatoes. Ventilate the greenhouse during hot weather. You can shade the plants with woven material or whiten the glass of the greenhouse.
Try to avoid damaging the plant's root system.
Plant seedlings at a distance from each other.
Get rid of stepchildren in a timely manner.
Shape the plants.
Do not use large doses of fertilizers.
Spray tomatoes with anti-rot preparations. Experienced gardeners recommend the use of Topsin M, Bayleton, Euparen multi.

Preparations for the treatment of gray blossom end rot of tomatoes: names, list, recipes for use

“Copper oxychloride” to protect tomatoes from gray blossom end rot
While signs of blossom end rot of plants (tomatoes and other nightshades) have not yet appeared, or you have collected and destroyed diseased fruits, it is advisable to spray healthy plants with universal products:

"Brexil Ca" is a powder containing calcium and boron. The solution is prepared from 10 g of powder per 10 liters of water.
“Copper oxychloride (CHOM)” is a greenish powder. The solution is made from 40 g of powder and 10 liters of water. They treat tomatoes 3-6 times per season.
“Tomato Rescuer” - ampoules with liquid. The product also helps against fungi. Once sprayed with the drug, it acts for about 1 month, and then you need to spray again.
"Megafol" - liquid in bottles from 25 ml to 25 l. A solution for tomatoes in open ground is made from 30-35 ml of liquid and 10 liters of water (weaker for a greenhouse).
The following drugs are also used: Nutrivant Plus , Fertivant , Tecamin Max .

Disinfection of planting material

First of all, the fight against rot begins at the seed treatment stage. Planting material must be disinfected using a solution of potassium permanganate or ferrous sulfate:

First, the seeds are soaked in 3% potassium permanganate for half an hour, then washed with warm water and dried.
Iron sulfate is dissolved in the ratio: 1 g of the drug per 1 liter of water. The seeds are soaked in the resulting solution for a day and then dried.

How is it distributed?

Under favorable conditions, the fungus botrytis forms conidia on the mycelium. These are the spores of the fungus through which it spreads within one season. In fungi of the genus Botrytis, conidia are colorless or smoky and invisible against the background of gray mycelium.

Conidia can travel through the air, with drops of irrigation water, and with tools. Due to them, the rate of spread of the disease is very high.

In autumn, sclerotia form on the gray coating - dark dots, visible to the naked eye, containing fungal spores. They are the overwintering phase of mold. Sclerotia are able to withstand frost and lack of moisture. After overwintering in the soil, sclerotia become the source of a new outbreak of the disease in the spring. They are able to germinate even after three years in the soil. Sclerotia of the fungus are preserved on plant debris and seeds.

Gray leaf spot

Gray leaf spot is otherwise called macrosporiosis and has nothing to do with gray rot. Gray spot in tomatoes is caused by fungi of the genus Stemphylium solani, and the causative agent of gray rot is the bacterium Botrytis cinerea Pers.

If a plant becomes infected with macrosporiosis, gray spots form on the leaves, which subsequently affect the leaves completely and the plant dies. When a plant becomes infected with gray rot, the stem is affected: it becomes covered with gray spots with an ashy coating. Subsequently, vascular necrosis develops inside the stem, and the foliage begins to turn yellow.

What causes spots on tomatoes

In most cases, spots on the leaves are, unfortunately, a symptom of a disease. There are many diseases in tomatoes. And most often they are caused by fungi. Less commonly, bacteria or viruses. The fungal infection usually begins on the lower leaves of the plant and, under favorable conditions, spreads very quickly.

Diseases such as cladosporiosis, late blight, septoria, phomosis and others greatly spoil the lives of us gardeners. And they may well be deprived of half the harvest if we don’t take action quickly. And here, whatever one may say, all measures come down to spraying with modern fungicides. Folk remedies are good for prevention. Biological products will help in the early stages of disease development. Well, when the fungus attacks on all fronts, “chemistry” is the most effective weapon. However, there are pathogens that are not susceptible to pesticides.

Let's find out what diseases are indicated by spots of different shades and shapes on tomato leaves. And we will select the most effective “medicine” for each disease.

Advice from gardeners

Experienced gardeners recommend the following method for combating rot: you need to add ash from burnt oak bark when transplanting seedlings (a glass of ash per hole), and also spray during the budding period.

An infusion for foliar feeding is prepared using 200 grams of ash and 10 liters of water. Place the ash in water, bring the solution to a boil, cook for 10 minutes and then leave for 24 hours. Then spray the tomatoes with it.

Tomatoes are often susceptible to various types of rot. To prevent this from happening, it is enough to follow agricultural practices, regularly and well water the plants, care for them, and also pay attention to varieties that are least susceptible to rot. All these simple measures will allow you to get a rich harvest and keep your plants healthy.

Symptoms of rot

Among the main signs indicating the presence of rot on tomatoes:

foci of rotting on fruits are gray-brown in color with a visible fluffy gray coating,
spots on areas near the attachment of leaves and tomato brushes,
tomato stems affected along the entire perimeter.

The most common gray rot of tomatoes occurs during the period of fruit ripening. Simultaneously with the stems injured by the fungal disease, which suffer primarily, without taking measures against it, the infection spreads to the top of the shoots, inflorescences and the vegetables themselves. As a result, if the pathogen is not treated and controlled, the fungus spreads rapidly throughout the greenhouse. Photos of summer residents who have encountered this disease allow you to get acquainted with the characteristic signs and appearance of damaged tomatoes.

Vegetables found to be rotten are immediately collected and destroyed to prevent the spread of fungal disease.

The fungal disease grows in 3-5 days, covering the stems with spots. A little later, the spots become pale to straw shades, turning into blurry stripes. For the first week, there is no sporulation of the rot fungus on the outbreak itself. Necrosis developing inside the stem leads to an obstruction of water supply through the affected area, resulting in the death of the vegetable crop. The leaves growing on top of the necrotic areas begin to turn yellow and fall off. Together with them, the stem is covered with aerial roots.

Other ways to fight

An effective way to combat gray mold on a plot is considered to be a set of agrotechnical techniques that help maintain the health of tomatoes and prevent the development of a fungal disease.

Maintaining an optimal level of humidity in the greenhouse and daily ventilation of the greenhouse. It is especially important to ventilate the greenhouse after watering by opening the windows and doors, otherwise the risk of proliferation of fungal microorganisms increases.
Caring for tomato bushes only in dry weather. During prolonged rains, it is better to avoid picking, replanting, weeding, loosening and other manipulations that can injure the plant.
Timely burning of tomato bushes with traces of fungal diseases.
The use of a drip irrigation system in the greenhouse prevents stagnation of moisture in the soil.
Mulching tomato bushes after each watering. Mulch maintains an optimal level of moisture in the soil, prevents stagnation of moisture and rotting of the root system. Humus, peat, hay and other organic materials, as well as non-woven fabric, can be used as mulch.
Correct formation of a tomato bush - do not allow the lower leaves or fruits to touch the surface of the soil. To remove leaves or pruning, use only disinfected garden tools. Agrotechnical procedures cannot be carried out in rainy, cold weather.

To prevent the development of gray rot, proper watering is very important. It is best to water tomatoes at the root, making small holes or grooves around the bush.

Root rot

From the name it is clear that it is the tomato root that is affected. In this case, unfortunately, only soil disinfection can help. For more severe cases of root rot, the topsoil will need to be replaced. Among chemical agents, a solution of copper sulfate will help. It should be used when infused under the root of the affected plant. Root rot is shown in the photo.

Internal rot

With this disease, the fetus is no different from the others. Only when slicing do the black inclusions in the pulp become visible. In this case, just like in all others, infusions for the root system and compliance with all necessary care procedures are necessary.

How to treat tomatoes against rot in a greenhouse

The most effective fight against fungal infection is complex. Prevention is necessary for healthy bushes and treatment of already affected plantings. Remember that the disease spreads rapidly in closed ground conditions.

Chemicals

If the rot is widespread, I recommend paying attention to special means:

Biological products: Trichodermin, Glyokladin.
Pesticide.

Turning to chemicals is a last resort. Their use makes the crop unfit for consumption until the waiting period has expired.

Folk remedies

Proven folk remedies are effective against rot:

Ash solutions and extracts. Ash contains calcium, boron, phosphorus, and manganese. These elements allow tomatoes to develop strong immunity.
Suspensions of calcium preparations. One of the main reasons for the development of rot is a lack of calcium.
Extracts of superphosphate solutions. Phosphorus helps develop strong immunity.

Let me draw your attention: folk remedies are effective only in the early stages of the disease. If the rot has spread widely, only pesticides and destruction of affected plants will help.