Black leg in tomato seedlings what to do? 5 rules for the prevention of black legs.
If the root neck of the seedling has turned black and then began to rot, then this indicates the development of a dangerous fungal disease. It is called the black leg, in the seedlings its development leads to lodging of the seedlings and its death. Very unpleasant disease. We will tell you what a black leg in tomato seedlings is, what to do and how, we will acquaint you with all the features of this disease and how to prevent it. And in a situation when the fungus has already appeared, effective treatment of the black leg will be required. All information about this issue is presented in the article.
Little information about the black leg
This fungus infects the seedlings as soon as the seeds begin to germinate. The chance of developing the black leg is maintained until 2-3 true leaves appear.
Black leg on tomatoes and peppers develops under the influence of the fungus Olpidium or Pythium. They are able to live in layers of soil located near the surface.Under normal conditions, these fungi feed on the tissues of dead plants. But with increasing humidity can move to a living sprout.
Black leg in seedlings of peppers or tomatoes begins with the fact that the root collar darkens. At the same time on the bottom of the stem there is a black constriction. This explains the name of the disease. If high humidity is maintained indoors, then after 5 days, the diseased stem softens. Sprout breaks down. Shoots wither and fall on the ground.
What contributes to the development of black legs?
The cause of the disease, that is, the spores of the fungus, often hides in the ground. But there are factors that aggravate the situation.
- Too thick sowing.
- Excessive watering of seedlings.
- Lack of ventilation in the room with plants.
- Sudden air temperature drop.
Therefore, it is important to observe the correct irrigation and ventilation regime in order to avoid the risk of developing a fungal disease.
How to prevent the development of black legs in seedlings of tomatoes and peppers?
Sow seedlings need in time. Early sprouted sprouts will be drawn out and become weak. The reason for this is the low temperature on the windowsill and insufficient lighting.To avoid such problems will have to put the seedlings in a warm room and provide it with additional lighting. Therefore, the black leg of tomatoes will not get a chance for development.
It is noticed that peat tablets allow you to get seedlings, which only in rare cases are affected by the black leg. This situation is explained by the fact that they are treated with a fungicide. Dive the seedlings of them is not necessary. It is simply placed in a larger container. Which also does not allow seedlings to weaken.
Prevention of black legs in seedlings of tomatoes and peppers
You can prevent the development of fungus. Just follow a few simple rules. Here are the rules that you need to follow if you do not want to worry about the black leg in tomato seedlings what to do.
Rule 1: Steam the soil before sowing.
The fight against the black leg should begin during the preparation of the soil. It should be thoroughly steamed. This can be done in a water bath. Pour the soil into a colander, place it over a saucepan with water. The pot should be filled to a quarter. Put everything on fire. It is necessary to boil water for at least 10 minutes, preferably 15. It is necessary to complete this procedure with “rest”.Leave the soil for 14 days. This period is necessary for useful microbes to wake up in the earth.
Rule 2: disinfection.
Pour the solution with potassium permanganate solution. Prepare it relies in proportion: 3 grams per 10 liters of water.
If there is a large number of seeds in the tank, then Trichodermin should be added to the soil. It is an active biological agent that is used for the prevention and treatment of various root infections, including fungus.
Rule 3: Soak the seeds.
You can make this treatment by placing the seeds in a gauze bag, and then lower it into a solution of any fungicide.
The black leg of the peppers and tomato will not develop after the seeds are soaked in “Elina”. A glass of water of this drug will require only 2-4 drops. But leaving the seeds in solution relies on 12 hours.
You can also treat the seeds of tomatoes and peppers with drugs that stimulate the immune system.
Rule 4: to create conditions that are favorable for the development of seedlings.
- After sowing and picking seedlings, it is recommended to sprinkle the surface of the soil with calcined river sand.
- Ensure that the soil is not overly wetted.
- If the crops are covered with foil, then they are supposed to be aired.
- Do not allow a sudden decrease in soil temperature. Especially dangerous is the moment immediately after watering.
Rule 5: Remove affected sprouts.
This is the first point related to how to deal with black leg. As soon as the first signs of the disease appear, these shoots should be removed and destroyed. The remaining seedlings should be watered with a solution of potassium permanganate, taking it in an amount of 3 g per 10 liters of water. Replace this solution can Bordeaux mixture, preparing a 1% solution.
How to get rid of a black leg?
Remember: the affected seedlings can not be saved. Therefore, they can only be thrown away. If the focus of the fungus is very large, then measures to combat the black leg are reduced to an urgent picking. Each sprout will need its own capacity. Put them in a warm room. If sunlight gets on the seedlings, then shading will be required.
What to do so that the black leg of the tomato seedlings does not appear again? After an urgent picking, you need to wait 6 days. Then put the tank in a room where it is cooler. The first watering of such seedlings should be carried out with a solution of a fungicide, for example, "Maxim" or "Fiotosporin". In this situation, you will need to make a solution with a concentration of 0.5-1%.
It so happens that the black leg strikes sprouts in a greenhouse. In such a situation, do not pick. But to shed the soil is necessary. Two biopreparations are used for this: “Alirin-B” and “Hamair”. On a bucket of water will need to take 4 tablets of these substances.