Diseases of seedlings

Seedling disease symptoms

Diseases in seedlings can be caused by various pathogens. Most often these are fungal infections, but can be bacterial, viral and caused by a lack of any nutrients.

Of course, each disease has its own symptoms, but in general, it is possible to understand that a plant is unhealthy by a number of signs:

• the color of the leaves has changed – they turned pale, turned yellow, turned brown, turned black, turned purple, dark veins appeared on a light background;
• the leaves began to deform – curl, wrinkle, turn inside out;
• the leaves are covered with spots or bloom, similar to mold;
• the leaves began to fall;
• the plant is very stunted;
• the plant wilts and does not recover after watering.

With any of these symptoms, you need to sound the alarm and start treatment as soon as possible.

Causes of seedling diseases

Most ku seedling problems are caused by pathogenic fungi. And for their development, in most cases, 2 conditions are needed:

• low temperature;
• high humidity.

If the seedlings are poured and stand on the windowsill, the chances that they will get sick are very high. The fact is that it is always colder on the windowsill than in the apartment – even from high-quality plastic windows it blows. The soil is very cold, and fungal spores are just there. And they are starting to grow. 

Types of seedling diseases

Of course, there are a lot of them, but we will consider the most frequent and most dangerous ones.

Blackleg

Another name for this disease is root collar rot. This is one of the most common seedling diseases. Most often it affects seedlings from the moment of germination until the appearance of 2 – 3 true leaves. Rarely seen later. Diseased plants usually die within a day (1).

Signs. As a rule, the lodging of seedlings becomes the main symptom of the disease – for no reason, individual seedlings suddenly begin to fall. If you look at them carefully, you will notice a black constriction on the stalk at the very surface of the earth.

Reasons. The black leg, like many fungal diseases, actively develops at high humidity and low temperatures. It spreads especially quickly in thickened crops. Lack of light can also provoke it.

Treatment. Alas, it will not work to cure diseased plants – they are doomed. If the seedlings are sown in boxes, you need to remove the affected plants together with a lump of earth as soon as possible, and plant the rest in separate cups. Cups with seedlings should be placed in a warm, bright place, slightly shaded from the direct best sun. After 5 – 6 days, water the seedlings with warm water with the addition of a fungicide. Suitable Maxim, Fitosporin, Baktofit (2).

Prevention. The black leg fungus lives in the soil, so the soil intended for seedlings must be calcined in the oven at a temperature of 90 ° C for 30 minutes. This must be done both with purchased land and with your own. The layer of soil for calcination should be no more than 5 cm.

After sowing the seeds, pour a small layer of sand (about 5 mm) over the ground, mixed with ash in a ratio of 2: 1. The sand dries very quickly, and in the area of ​​​​the root collar it will always be dry. And the ash will additionally protect the seedlings from pathogens.

What culture strikes. Most often, cabbage, onions and strawberries suffer from the black leg, less often – tomatoes and peppers. 

Risectoniasis

This is one of the varieties of rot, which primarily affects the roots. Pathogen spores persist in the soil and on plant debris (3).

Signs. In diseased seedlings, the roots are covered with a rusty coating. However, it is not visible underground. With the development of the disease, signs also appear above the soil surface – the stem below the cotyledon leaves becomes dark and thinned. And, as a rule, the disease does not rise higher. However, the leaves, due to the fact that the vessels are affected, acquire a blue-green tint. 

Affected plants usually die, and if they survive, they lag far behind in development and practically do not produce a crop.

Reasons. The disease develops at high soil moisture, high temperature – 28 – 30 ° C and lack of light.

Treatment. It does not make sense to treat affected plants, they need to be removed as soon as possible. If the disease has affected the seedlings in the boxes, healthy plants should be planted in cups as soon as possible, put them in a cooler, well-coordinated place and let the soil dry out.

Prevention. Before sowing seedlings, you need to calcine the soil in the oven – the spores of the pathogenic fungus live in the soil. It is important that the container intended for seedlings had drainage holes so that moisture does not stagnate.

What culture strikes. Most often found in seedlings of tomatoes, peppers, cucumbers and beans.

Fuzarioz 

This disease is also called Fusarium wilt. It is very dangerous, and what is most unpleasant is that it quickly spreads to neighboring plants. The causative agent of the disease persists on plant residues in the soil (4).

Signs. The disease spreads from the bottom up. First, the lower leaves are affected – they wither, turn yellow and fall off. On the leaves above, the veins become colorless, the petioles are bent, the leaves themselves begin to curl. The tops of the plants are drooping. A pink bloom often appears on seedlings.

Reasons. Infected seeds or soil. The fungus-pathogen actively develops at high soil moisture.

Treatment. At the first signs of the disease, seedlings should be watered with Previkur or Quadris preparations (2).

Prevention. The spores of the pathogenic fungus persist in the soil, so it is useful to ignite it in the oven before sowing the seeds. Seeds before sowing are useful to pickle with Maxim (2). If you collect your seeds, take them only from healthy plants.

What culture strikes. This disease is “omnivorous”, affecting the seedlings of most vegetables.

Verticillary wilting

This disease affects the vessels of plants, develops slowly and often becomes chronic. Pathogen spores overwinter on plant debris in the soil (5).

Signs. The first sign of verticillosis is that the leaves of the seedlings wither. And, only during the day. And at night, the plants become elastic again. Gradually, the leaves change color – spots appear along the edges, and the tissue between the veins begins to die, forming V-shaped yellowing.

Reasons. Infected soil – spores of the pathogen fungus can persist in the soil for up to 15 years. Or infected seed – the pathogen is able to penetrate the seeds. The development of the disease is facilitated by sudden changes in air temperature and soil moisture, too frequent and abundant watering, lack of light.

Treatment. At the first signs of the disease, seedlings should be watered with Maxim Dachnik – according to the instructions.

Prevention. Before sowing, the earth must be calcined in the oven – most often, the infection of seedlings occurs precisely through the soil.

What culture strikes. It can occur in many vegetables, but most often affects tomatoes, peppers, eggplants, cucumbers and strawberries.

pounds

This is a specific disease of plants of the Cabbage family (6). 

Signs. The main symptom of the disease is wilting seedlings. Moreover, unlike the black leg, in which the root neck turns black, the keel has no external manifestations – the disease affects only the roots. But if you dig up an infection of a plant, it is very easy to recognize the pathology – growths will be visible on the roots.

Reasons. As a rule, the infection enters seedlings through infected soil. Actively develops with high acidity of the soil and high humidity.

Treatment. In plant protection reference books, it is recommended to pour affected plants with a solution of copper sulfate (5 g per 10 liters of water), however, most experts agree that it makes no sense to treat diseased plants, they need to be destroyed as soon as possible so that the disease does not spread to the rest of the seedlings . 

Prevention. Before sowing, ignite the earth in the oven. And never sow seeds in acidic soil.

What culture strikes. All types of cabbage. And also radish, radish, mustard.

Seedling disease treatment methods

Fungal diseases are very difficult to treat and often can only slow down their development. And many are completely incurable. Therefore, prevention is the most important. And here’s what you should pay attention to:

• the ground and containers must be disinfected before sowing seeds for seedlings;
• containers should have drainage holes so that excess water flows through them;
• the soil must be fertile – if the seedlings lack nutrients, it will grow weak, and this is easier to attack by pathogens;
• watering should be moderate – it is important that the surface of the soil between them dries out;
• light and heat should be in abundance.

In a word, it is important to observe the agricultural technology of culture. Any deviations or experiments with folk advice often lead to illness, and even death of seedlings.

Popular questions and answers

We talked about the problems of growing seedlings with agronomist-breeder Svetlana Mikhailova.

Sources of

1. Akhatov A.K., Hannibal F.B., Meshkov Yu.I. and others. Diseases and pests of vegetable crops and potatoes // M .: Partnership of scientific publications of KMK, 2013 – 463 p.
2. State catalog of pesticides and agrochemicals permitted for use on the territory of the Federation as of July 6, 2021 // Ministry of Agriculture of the Federation

   https://mcx.gov.ru/ministry/departments/departament-rastenievodstva-mekhanizatsii-khimizatsii-i-zashchity-rasteniy/industry-information/info-gosudarstvennaya-usluga-po-gosudarstvennoy-registratsii-pestitsidov-i-agrokhimikatov/

3. Peresypkin V.F. Diseases of agricultural crops. Volume 2. Diseases of industrial crops and potatoes // Kyiv, Harvest, 1990 – 248 p.
4. Grebenshchikov S.K. Reference manual for plant protection for gardeners and gardeners (2nd edition, revised and additional) / M .: Rosagropromizdat, 1991 – 208 p.
5. Peresypkin V.F. Agricultural Phytopathology, 4th ed., revised. and additional // Moscow, Agropromizdat, 1989 – 480 p.
6. Akhatov A.K., Jalilov F.S. and others. Protection of vegetable crops and potatoes from diseases // M .: Moscow printing house No. 2, 2006 – 352 p.