Tobacco mosaic disease (TMV), which harms tobacco quality and yield, will cause huge economic losses to tobacco farmers. In serious cases, it is as high as 50%. The practice has shown that the prevention and control of tobacco mosaic disease have specific difficulties, but if the appropriate control technology is adopted according to the practical situation, it can reduce most of the losses to a certain extent.
Which microbe causes tobacco mosaic disease? Tobacco mosaic virus (TMV), an RNA virus, is the causative agent of tobacco mosaic disease. It is currently the most widely distributed and most common type of disease in tobacco production, which is exceptionally harmful to tobacco. Tobacco mosaic disease and tomato mosaic disease have long been known. Mosaic symptoms appear on the leaves, the growth is in a bad state, and the leaves are often deformed.
Symptoms of Tobacco Mosaic Virus
Tobacco mosaic disease can be infectious. At the early stage of the mosaic disease, the new leaves have bright veins, dark green and light green, and the mesophyll tissues around the seams are lighter in color, showing a translucent shape, and spread from the root of the leaf to the tip of the leaf.
The appearance of the rear leaves will change significantly, forming a yellow-green tobacco mosaic disease.
Causes of Tobacco Mosaic Diseases
Tobacco can be infected with the mosaic disease from the seedling stage to the mature stage.
During the tobacco seedling stage, tobacco seedlings are infected due to the operations of tobacco farmers, such as thinning seedlings.
During the growth stage of tobacco seedlings, agricultural activities such as fertilization, priming leaves, and mulching will cause tobacco seedlings to be infected with the mosaic disease.
When the tobacco plants have flower buds, tobacco farmers will cap and pick, which will cause the spread of mosaic disease.
Tobacco takes only about one week from infection to onset of foliar disease, and the optimum temperature for the condition is between 28 and 30°C. If the temperature is lower than 12°C or higher than 38°C, the incidence of the disease will be reduced to some extent.
After the tobacco plant transplant, if the temperature fluctuations, drought, sudden changes in temperature will increase the occurrence of tobacco leaf disease.
Treatment of Tobacco Mosaic Disease
1. Reduce the Source of the Virus
The use of dry-water rotations is effective in reducing the incidence of foliar diseases，but is not suitable for dry-water rotations in the legume, aubergine and crucifer families.
Sanitize the agricultural tools that need to be applied before planting.
In daily farming operations, tools need to be clean and non-toxic, and diseased tobacco strains need to be appropriately disposed of in a timely manner.
Choose suitable tobacco varieties, and breed disease-free tobacco seedlings, use straw return technology to improve the soil structure to improve the resistance of tobacco plants to disease, has a specific effect.
2. Chemical Control
The proliferation of aphids will aid in the spread of foliar diseases, and killing them can effectively reduce the rate of foliar disease infection. Aphid control can be carried out with the choice of oxaliplatin, vanillin, imidacloprid, etc.
In the early stages of foliar disease, the best results were achieved by spraying the right parts of the tobacco plant with 80% zinc dexen 500 times dilution once a week for three weeks.
Spraying with disinfectant can be used for prevention during agricultural processes such as leaf-cutting, seed removal, and topping, and can last for two weeks at a time.
Research shows that if the disease is found in the smoke field, it needs to be immediately sprayed and fertilized with water to have a good yield retention effect.
3. Organic Solution
Use plant elicitors, such as harpin protein, chitosan oligosaccharide, to excite the plants’ immune system response, using their own immunity to fight the virus and be healthier and greener.
The use of amino acids, seaweed fertilizer can enhance plant nutrient utilization and plants’ resistance to climate change and other stresses.
Humic acid enhances soil structure and avoids secondary damage to plants by soil clumping.
Long-term application of microbial fertilizers helps to balance the soil flora, suppress the invasion of harmful diseases, stimulate the immune response of plants, and maintain functional growth status.
Some microbes like beauveria bassiana, metarhizium anisopliae can avoid the reproduction of aphids effectively, the application of them will help the world’s environmental protection cause.
As long as the selection and breeding of excellent tobacco varieties, pay attention to the disinfection of appliances while maintaining scientific management of water fertilizer, the reasonable use of biostimulants. The immediate destruction of disease-causing plants to prevent spread can effectively slow the spread and spread of viral diseases.