Surely many of those who have their own garden at least once had to see the consequences of the tobacco mosaic virus. In this article, you will learn how to prevent this disease in tomatoes.
Brief historical background
For the first time this disease was recorded at the end of the 19th century in the process of growing tobacco. Bright marks appeared on the infected bush. Over time, he began to lose shape and eventually died. After that, the disease gradually spread to neighboring plants, and after a short time, entire plantations became unsuitable for further cultivation.
The only available at that time method of struggle was considered the complete destruction of infected seedlings. Such measures allowed the rest of the plants to be preserved. Many years after the discovery of this disease, Dr. Ivanovsky managed to identify its cause. It turned out to be the tobacco mosaic virus.
Development mechanism and biology
The causative agent of this disease is characterized by resistance to external factors. It was found that the virusable to persist even at elevated temperatures.
Tobacco mosaic completely infects plant tissues at the cellular level. The cause of its occurrence is considered to be the partial breakdown of chlorophyll and damage to chloroplasts. As plastids are destroyed, carbohydrate levels decrease. As a result, the mechanism of death of individual tissue sections is activated. The causative agents of the disease are Solanum virus 1, Cummis virus 2 and Nicotina virus 1.
Main symptoms
In the beginning, the leaves, on which the tobacco mosaic appeared, become speckled. Spot color may vary. They are whitish, bright green or light yellow. Gradually, the leaves begin to wrinkle and deform, acquiring a filamentous or fern-like shape.
In addition, tobacco mosaic leads to crushing and uneven ripening of fruits. The development and growth of an infected plant is slowed down. Due to a violation of water metabolism, the leaves and stems dry out. Young shoots die first. Damaged fruits turn brown and begin to rot.
How does infection happen?
Tomato mosaic can be transmitted as a result of contact with infected crops or mechanical damage that occurs during processing. Often, infection occurs during a dive of dense seedlings.
Tobacco mosaic is also distributed withthe help of vectors such as bed bugs, aphids and other insects. The virus can be transmitted through seeds and fruits carried by animals and birds. The main breeding ground for infection is the soil located under the roots of diseased tomatoes. This is due to the fact that plant remains can be preserved in it. Mosaic develops especially rapidly in conditions of high humidity. It has been established that raindrops flowing from the leaves of infected plants can also become a carrier of infection.
Tobacco mosaic: treatment and prevention
This infection can destroy about 20% of the entire crop. Therefore, it must be fought. To protect your plants, you must use only high-quality planting material. Seeds, boxes and other garden tools are recommended to be treated with a five percent solution of potassium permanganate. Such manipulations must be carried out for four days in a row.
To prevent possible infection of the future crop, preventive measures should not be neglected. So, it is important to vaccinate tomatoes with an aggressive strain. When planting plants in a greenhouse, appropriate protective measures must be taken. To disinfect the seeds, it is recommended to pre-soak them in a twenty percent hydrochloric acid solution and rinse thoroughly under running clean running water. You should also steam the soil by pouring boiling water over it for two or three hours.
At least once a week, seedlings are recommended to be treated with milk diluted with ordinary water in a ratio of 1:10. Above allamong other things, it is important to carry out timely replacement of the soil in the greenhouse, removing a ten-centimeter layer from it along with the remains of plants.
One week before planting in the soil and fourteen days after it, the seedlings should be sprayed with a one percent solution of boric acid. Thanks to this, it will become more resistant to viruses. Measures aimed at the destruction of insects that can become potential carriers of the mosaic pathogen cannot be neglected. Also, in order to prevent the likely spread of tomato tobacco mosaic, experts recommend treating greenhouses, collecting and burning autumn leaves and old plant roots.
