1. Viral Disease- Here given some viral diseases of plants.
Mosaic disease of tobacco- This disease caused by Tobaco Mosaic Virus (TMV). When affected the leaves of a plant get shrinked and small. The chlorophyll of the leaves damaged. To control this disease from spreading, the affected plants should be burnt.
Bunchy top of Banana- Banana virus causes this disease in plants. The plants becomes dwarf and all leaves bunched together on the top like a rose.
2. Bacterial Diseases - Here given some viral diseases of plants.
Wilt of Potato- This is also known as ring disease, a brown ring formed on the xylem. This disease is caused by bacteria called Pseudomonas solonacearum. In this disease the conduction system of the plant is affected.
Black arm of Cotton – This disease is caused by Xanthomonas bacteria. In this disease a watery spot of brown color formed on the leaves.
Bacterial Blight of Rice- This disease is causes by Xanthomonas oryzae bacteria. An yellow-greenish spot is found on both side of leaves affected with this disease. Vascular bundles get blocked due to growth of bacteria.
Citrus Canker – This disease is caused by Xanthomonas citri bacteria. In this disease whole plant including leaves, branches, fruits get affected. This disease was first seen in China.
Tundu Disease of Wheat- This disease caused by Corinobacterium titrici bacteria and Enzuina Titriki Nematode. In this disease lower parts of the leaves are faded and turned.
3. Fungal Diseases – The diseases caused by different types of fungi to plants called fungal diseases.