Causes of diseases and pests on seedlings
Problems with seedlings growing on a windowsill and plants in a greenhouse or open ground are different. Diseases that are detected at home are not dangerous for adult bushes. Conversely, seedlings grown at home cannot develop certain types of infections due to insufficient conditions for their development.
Diseases such as fusarium wilt, late blight, bacterial black spot, tobacco mosaic, powdery mildew and bacterial canker are characteristic of peppers growing in open ground or in a greenhouse.
Factors that provoke pepper diseases at the seedling stage:
- contaminated substrate or seeds;
- improper cultivation techniques;
- placing seedlings next to indoor plants.
Self-prepared, not disinfected soil, violations of irrigation and temperature conditions in agricultural technology often lead to the development of diseases in pepper seedlings. Also, the outbreak of phytopathologies is facilitated by own seed material that has not undergone the dressing procedure.
But pests on pepper seedlings can appear not only due to poor-quality soil. Phytophages are able to move to seedlings from infected indoor plants. Pests are also carriers of many infectious diseases that are dangerous to young seedlings.
Most often, diseases of sweet pepper seedlings such as blackleg, root rot, chlorosis and oedema are found at home.
Fusarium wilt
A dangerous viral disease that practically does not manifest itself in the first stages. Signs are noticeable during the formation of vegetables. At the same time, the foliage becomes lighter, becomes almost white, then turns yellow and falls off.
The disease cannot be treated; it is more advisable to tear out the bush and burn it. To avoid fusarium when growing peppers, you should follow all preventive measures: remove weeds in a timely manner, disinfect the soil and seeds before planting.
Blackleg
Among the diseases of pepper seedlings, blackleg ranks first. Most often, the development of infection is caused by fungi of the genus Fusarium. Pathogenic microorganisms may be present on infected seeds or in the substrate.
The rapid development of fungi is promoted by:
- increased soil moisture;
- watering with cold water;
- low temperature or sudden changes therein;
- thickened plantings.
The disease occurs when peppers have cotyledons or 1-2 true leaves.
The first sign of a fungal infection is the formation of a black constriction on the stem in the area of the subcotyledon (see photo). In the affected area, the shoot becomes thinner and the young plant falls. In this case, the upper part of the stem and the root are not affected.
Diseased seedlings are immediately removed along with a lump of earth. The place where the infected seedlings grew is dotted with a small amount of potassium permanganate solution (0.1 potassium permanganate is used per liter of water). Externally healthy peppers should not be watered with the product.
The box where the diseased seedlings were located is moved away from the rest of the seedlings.
The next stage of the fight is emergency drying of the soil by increasing the temperature and ventilation. To do this, loosen the rows and sprinkle the soil with ash or calcined sand.
If possible, install a fan next to the seedling box. Placing a lamp directly above the plantings will also help speed up drying. The distance between the light source and the tops of the stems should be about 15-20 cm.
After drying the top layer of the substrate, you can spray the plants with Previkur or Fundazol. Copper-containing preparations are also suitable for processing.
Among the biological products used for the disease, Trichodermin or Sporobacterin are used, which suppress fungal pathogens at any stage of development.
You can save seemingly healthy seedlings that grew in a common container with diseased plants by emergency picking. This method is suitable if the peppers already have 1 or 2 true leaves.
For preventive purposes, transplanted seedlings are shed with a solution of Fitosporin M. Some gardeners try to treat already diseased plants with this drug, but the biofungicide is ineffective against a rampant fungal infection.
Root rot
According to the description of the symptoms, root rot is in many ways similar to blackleg. But unlike the latter, this type of fungal infection does not develop so rapidly. Typically, the disease affects seedlings after they are planted in contaminated soil.
If pepper seedlings become sick with root rot, the leaves turn pale and gradually turn yellow. A gray, whitish or dark green coating appears at the bottom of the stem, and a constriction forms.
Pathogenic fungi first feed on roots that were damaged during picking. Then the pathogens move to healthy roots and only then to the lower part of the stem.
When a diseased plant is removed from the soil, an almost complete absence of the root system is discovered. Because of this feature, the disease received a second name - rootworm. Treatment methods are similar to those used in the fight against blackleg.
Trichodermin and copper-containing drugs are effective against infection. Additionally, the soil is dried and sprinkled with ash.
White spot
A fungal disease, the first signs of which appear on the lower leaves. Gradually, the infection completely affects the bush. Brown spotting is characterized by gray-white spots with dark edging. The peak of the disease is indicated by the appearance of black dots on the spots. These are fungal spores.
White spotting is treated by spraying with special antifungal drugs, for example, Fitosporin or Trichodermin. If the bush is completely affected, it is pulled out and burned. For prevention purposes, it should be treated with a weak solution of potassium permanganate.
Non-infectious chlorosis
The development of non-infectious chlorosis in pepper seedlings may be due to the following reasons:
- acidic or alkaline soil;
- lack of light and heat;
- overmoistening or drying out of the substrate.
The disease can also be provoked by a lack of elements in the substrate such as nitrogen, iron, magnesium, calcium.
With chlorosis, yellow spots appear on the leaves and they curl. Plants develop poorly and stop growing. The new leaves that appear become smaller, and the yellowed ones dry out and fall off.
Treatment of the disease comes down to correcting errors in the rules of agricultural cultivation. If there is a lack of elements in the soil, fertilizing with complex mineral fertilizers and leaf treatments with growth stimulants (Epin Extra) are carried out.
Marsupial fungus
A disease common to all plants. The official name is sclerotinia. It begins to develop in the root zone and gradually moves to the fruits. Vegetables lose their flavor, become soft and unsuitable for food.
The main symptom of marsupial fungus is that the leaves turn white. Clearly defined spots appear on them, in the center of which black dots (fungal spores) form.
The affected plant is immediately removed and the soil around it is disinfected. Nearby crops are treated with a copper-based solution.
Oedema
The second name of the disease is dropsy. Refers to non-infectious diseases of pepper seedlings, caused by swelling of the leaves from excess moisture.
Often, signs of oedema are confused with damage to seedlings by pests such as aphids, spider mites and scale insects. When swelling occurs, white pimples appear on the inside of the leaf. Over time, the affected leaf blade may curl and fall off.
The development of the disease is provoked by not regular but abundant watering of seedlings, artificial supplementary lighting, lack of heat, dense plantings and sudden temperature changes.
Treatment comes down to drying the soil or transplanting plants into a dry substrate. The seedlings are also provided with sufficient light and heat.
Verticillium wilt
The disease appears even before flowering begins. Its distribution occurs from bottom to top. The first spots appear on the lower tier of leaves. The whitish areas gradually grow. The leaves turn yellow and fall off.
If untreated, only the upper tier of foliage will remain. If you cut the stem, you can see its darkening and necrosis of blood vessels.
A favorable environment for the development of the disease is elevated temperature (more than 25 ° C) and low humidity levels. Most often, the development of the disease is provoked by repeated planting in the same place. After the cold weather, the bushes begin to recover.
Pests on pepper seedlings
Most often, at home, pepper seedlings get sick due to the appearance of pests on them. Phytophages feed on the leaves and stems of young seedlings, as a result of which the plants die. The most common pests of pepper seedlings:
- aphids;
- scale insect;
- thrips;
- whitefly;
- spider mite
Phytophages pose no less a threat to pepper seedlings than fungal diseases.
Aphids
The pest appears on pepper seedlings from soil infested with larvae. Insects can also move from sick indoor plants. A characteristic sticky coating appears on the leaves of peppers.
Over time, the leaf plates curl, the resulting buds do not open, and the flowers become deformed. The seedlings gradually dry out.
If plants are severely damaged, black or white insects can be found on the inside of the leaves.
Thrips
Bell peppers are a favorite crop for thrips. Pests are attracted to the sweet sap of seedlings and delicate tissues that are easy to bite through at the seedling stage.
At the initial stage, the phytophage is very difficult to detect on plants. Most often, a gardener notices a thrips colony when the seedlings are severely affected.
Eggs and larvae of pale gray or yellow-white color appear on the inside of the leaf and look like pimples. The leaf plate is deformed, brown or gray spots form.
Shchitovka
Externally, the pests resemble rounded tubercles of green, yellow or brown, several millimeters in size. The location of insects is the area along the veins on the leaf blades.
A sticky secretion is formed on the seedlings as a result of the pest's activity. Seedlings stop growing, become pale, turn yellow, leaves curl, dry out and fall off.
Whitefly
The infestation of pepper seedlings by whitefly is difficult to confuse with another type of pest. White spots appear on the leaves, then they turn yellow. The affected vegetative parts fall off over time.
On the reverse side of the leaf blades you can find larvae that look like white or green sticks.
When the population increases greatly, adults line the outer part of the leaf. Outwardly they look like small butterflies.
Spider mite
Due to the microscopic size of spider mites, it is difficult to detect at the initial stage of plant damage. During the activity of the pest, yellow necrotic dots appear on the leaves.
On the inside of the leaf blades you can find a thin, barely visible cobweb and a gray coating similar to dirt.
Viral diseases of bell pepper
These include a number of diseases that cause pathology in plant development. They are carried by insects.
Tobacco mosaic
The causative agent of tobacco pepper mosaic is the Tobacco mosaic virus. It causes the greatest damage in greenhouse crops.
Signs of the disease
Spots appear on pepper leaves that resemble a marble pattern. Plants lag behind in development. Sometimes necrosis occurs along the main veins of the leaf.
Preventive measures
- processing of seed material;
- dressing of greenhouses;
- selection of resistant pepper varieties.
Control measures
In risk areas, 7 days before planting the plants in the garden, seedlings are treated with boric acid, repeating it 7 days after planting.
Tobacco pepper mosaic. © vehiclelicensing
Stolbur
Stolbur, or phytoplasmosis, or woodiness of pepper fruits loves hot, dry weather. Spread by cicadas. It is conditionally placed in the group of viral diseases, since the disease is caused not by viruses or fungi, but by mycoplasmas.
Signs of the disease
The manifestation of phytoplasmosis begins from the top of the head. On the upper shoots, the edges of the heavily corrugated leaves curl up and dry out, but the leaves do not fall off. Gradually, this manifestation descends on the entire plant. In this case, the internodes grow short. Flowers appear, but they are sterile. If the pepper fruit sets, it grows ugly, curved like a beak, hard, and turns red early.
Preventive measures
- elimination of weeds, in particular bindweed, thistle, thistle (these mycoplasmas are very fond of them);
- since leafhoppers are easily carried by the wind, it is advisable to protect the site from the main prevailing winds;
- treating beds against leafhoppers with Fufanon and Karbofos (in the evening);
- selection of resistant pepper varieties;
- dressing of seed material, since stolbur loves plants weakened by fungal and viral diseases;
- destruction of diseased plants.
Signs of phytoplasmosis in bell peppers
