The disease is caused by the Tobacco Mosaic Virus and its strains. Infected plant residues can survive in foreign weeds, as well as in cigarette and tobacco remnants. On the leaves, mosaic-like spots of light green, yellow, and dark green colors can be observed. Curling and deformation are evident on the leaves, leading to stunted growth in plants. Purple discoloration appears on the leaves. Long brown streaks are visible on both leaves and fruits. Suspicious plants in seedbeds and greenhouses should be destroyed. Hands should be thoroughly washed with soap and water before any maintenance procedures. Tobacco should not be smoked in areas where plants are present. Tools used in maintenance should be disinfected with a 5% solution of hypochlorite water.

This disease is transmitted by whiteflies and is not spread through seeds or direct contact; its primary host is the tomato plant. It causes abnormal-shaped and significantly reduced leaves, along with severe stunting. Leaves formed immediately after infection curl downward, and subsequent leaves exhibit a deformed appearance. The leaves also take on a boat-like shape. Plants infected in the early stages experience halted growth, while late-stage infections result in reduced fruit set. Although there may be no visible symptoms on flowers, flower drop is quite common. To prevent the disease, thorough observation is essential. Controlling weeds that act as hosts for the virus and whiteflies, both inside and around the greenhouse, is crucial. Growing tomato varieties resistant to the disease is recommended, and using screens in greenhouses can help manage whitefly populations.

The symptoms initially appear on older leaves as small, dark-colored, and watery lesions, which gradually expand to form lesions with black or brown edges and small black circular centers. Lesions on the stem, petiole, and calyx are longer and develop pycnidia in their centers. When the disease is severe, it leads to leaf collapse and ultimately the complete loss of plant leaves. Prolonged periods of high relative humidity and temperatures between 20-25°C are conducive to infection and disease development. The disease can be spread through personnel clothing, tools, or agricultural equipment via insects. Removing or plowing under all plant residues along with implementing agricultural practices like a three-year crop rotation, in conjunction with a robust fungicide program, can help reduce losses caused by this disease.

It is mechanically transmitted, meaning that any contact with the virus can spread the disease. Pruning, tying, cultivation, spraying, and harvesting activities are ways the virus can be transmitted. Materials such as clothing, shoes, equipment, and tools can carry and spread the virus. Additionally, transmission can occur through bumblebees and insects. Leaves of infected tomato plants may exhibit symptoms such as yellowing along veins, mosaic patterns, intermittent leaf narrowing, and blistering. Fruit color is affected, leading to brown, green streaks, or yellow spots. The fruit becomes hardened and remains unripe, resulting in a reduced yield of fruits. This, in turn, lowers the market value of tomatoes. Personnel working in production areas should wear clean work clothes and gloves for each greenhouse. Clean clothes should be worn daily, hands should be washed with soapy water, and disinfectant-soaked doormats should be used at all greenhouse entrances. Tools and equipment used should be disinfected. All plants and plant residues in the greenhouse identified as infected should be completely destroyed and disinfected in contaminated areas. Colonies of bumblebees in contact with infected plants should not be used.

The virus is highly stable and can retain its ability to cause disease for a long time in various environments. Infected plants can remain viable for weeks without losing their vitality. The virus can easily spread in production areas through infected tools and equipment, contact between hands, clothing, shoes, and infected plants during harvesting. Additionally, it can be transmitted during cultural practices. The virus can be carried by bumblebees used as pollinators in greenhouses to healthy plants. The transmission may vary depending on the plant species, variety, growth stage, and climatic conditions. Cultural measures should be taken, and hygiene rules for virus prevention must be followed in production areas. Personnel working in production areas should use clean and separate work clothes and gloves for each greenhouse. Clean clothes should be worn daily, hands should be washed with soapy water, and disinfectant-soaked doormats should be used at all greenhouse entrances. Tools and equipment used should be disinfected. All plants and plant residues identified as infected in the greenhouse should be completely destroyed, and contaminated areas should be disinfected. Colonies of bumblebees in contact with infected plants should not be used.