Tobacco diseases: how to identify infection and pests, what to do

Tobacco is considered a fairly common crop, the cultivation of which has a number of features. For it to be successful, it is important to strictly adhere to the basic agrotechnical recommendations. However, sometimes the process is accompanied by various kinds of problems. Among them, it is worth highlighting the development of diseases and pest attacks. To cope with the problems, it is important to identify the causes of tobacco diseases and take measures to eliminate them.

Black Root Rot

In most cases, this disease affects seedlings, but sometimes adults also suffer.Leaves on diseased bushes wither, turn yellow and dry. In this case, the roots become black in color and often die off. In mature plants, the foliage withers, and black and white spots appear at the ends of the roots.

The cause of the disease is a fungal infection. It often provokes the death of seedlings. When it is planted in open ground, there is a risk of thinning the plantation.

Black leg, or seedling rot

Tobacco is highly susceptible to this disease. With its development, darkening and thinning of the base, and then most of the stem, is observed. As a result, damaged bushes die. Most often, the pathology spreads in foci. However, sometimes the whole seedling suffers. The cause of the disease is fungi.

With diseased seedlings, the disease can enter plantations and cause them to thin out. Most of all, the pathology manifests itself with high humidity, excessive fertilization and thickening of plantings.

Dry root rot

Young bushes are more affected by this disease. Pathology is accompanied by wilting of the foliage and thinning of the roots. As a result, the entire bush dies. The causative agent of the disease is the lower fungus Olpidium nicotianae Preiss. When bushes are infected, there is a significant thinning of plantings in greenhouses.

Powdery mildew

This pathology is accompanied by the formation of a white powdery coating on the bushes. At first, it covers individual areas, and then the entire surface of the leaves. The bottom foliage suffers first.

The causative agent of the pathology is the marsupial fungus. It can accumulate in weeds and spread to cultivated plants. Pathology leads to a noticeable decrease in the grade of tobacco. The fact is that the damaged foliage during drying acquires a brown color and loses its taste.

Downy mildew, or downy mildew

This is the most common tobacco disease. With its development, the leaves and cotyledons of the sprouts are covered with yellow-green spots. After that, the edges of the foliage twist down. In the area where the spots are located below, and sometimes above, the leaves form a gray-violet coating.

At high humidity, the affected fragments of foliage darken and become oily. The plant wilts quickly. With the rapid development of pathology, seedlings die in 3-4 days. This process is accompanied by an unpleasant odor.

In the field, downy mildew is characterized by the formation of chlorotic spots on foliage. At the same time, their shape and size are determined by weather conditions and varietal characteristics. Most often, the spots are rounded and limited to the veins of the leaves.

This disease is considered very dangerous. Affected seedlings die completely. If mature plants are not treated in time, they produce poor quality crops.

Brown dry spotting, or Alternariosis

This pathology most often develops in the second half of summer. In this case, the foliage is covered with large round spots of a brown hue. They are covered with a dark velvety coating.

The causative agent of dry brown spotting is considered to be a fungal infection. In plaque zones, conidiophores with conidia are formed. The risk of pathology increases during the rainy season and can lead to serious losses in the yield of leaves and seeds.

Bacterial vendace

If the leaves are infected with bacteria, sharply defined spots of various shapes appear on them. After some time, their sizes increase and merge with each other. The spots are white or brown in color. In this case, the affected areas fall out. After them there are holes.

Tobacco ryabukha is most pronounced in early summer. The disease is not contagious. In this case, bushes that grow in open areas suffer the most. The risk of developing the disease increases with low soil fertility and sharp temperature fluctuations.

Tobacco or common mosaic

This pathology is characterized by the formation of light green spots that alternate with the normal green of the leaf. With seed infection, yellowing of the veins on young foliage is observed. In this case, the plates are covered with specks. The edges of the youngest foliage curl up a little, forming a rim. After that, large bubble-like swellings form on them. Sometimes the leaves become threadlike.

Cucumber mosaic

This type of mosaic is accompanied by the formation of spots on the plant. At the same time, the bushes become covered with dark green blisters, and the ends of the leaves dry up.

The causative agent of the disease can hide in cucumbers, tomatoes or pumpkins for a long time. Peach aphid spreads cucumber mosaic. That is why it is so important to take action to combat it.

Bronze, or apical chlorosis

External signs of pathology depend on the affected area of the culture. The most famous sign is the formation of a pattern on leaf blades. It forms lines, circles or weaves. Young plants that are affected by bronze usually die. Thrips are considered carriers of pathology. That is why it is so important to fight these pests.

White Moth

This pathology is characterized by the formation of small necrotic spots of various shapes. They can be 2-10 millimeters in diameter and differ in pronounced zoning. Later, the spots become lighter in color, and the zoning disappears.

Viral infection is inactivated when the foliage is dried. Pathology spreads peach aphid. In this case, the infection may remain in the seeds.