Bipolaris sorokiniana (Sacc.) Shoemaker (Syn. Helminthosporium sativum, telomorph: Cochliobolus sativus), a hemibiotrophic phytopathogenic fungus is a well known cause of spot blotch disease in barley (Hordeum vulgare L.). The disease is found all the places where barley is grown. Foliar spot blotch has emerged as the major biotic stress hampering the commercial production of barley. This book provides information on morphological, pathological and molecular diversity in the B. sorokiniana and will be helpful for the understanding the role of melanin in B. sorokiniana. Resistance components identified will be helpful for the management of spot blotch disease.