Bipolaris sorokiniana causes spot blotch of wheat in warm and humid regions. This disease has emerged as a critical challenge to wheat cultivation, especially in the warm and humid areas of the world. The symptoms include early lesions characterized by small, dark brown and 1 to 2 mm long without chlorotic margin. In susceptible genotypes, these lesions extend very quickly in oval to elongated blotches, light brown to dark brown in colour.