Banded leaf and sheath blight: A menacing disease of maize (Zea mays L.) and its management

Maize (Zea mays L.) crop is attacked by number of fungal, bacterial and viral diseases, out of which banded leaf and sheath blight (BLSB) caused by anastomosis group 1-IA of Rhizoctonia solani f. sp. sasakii Exner. is one of the most widespread and destructive disease of maize in Southeast Asian countries. The occurrence of this disease has also been reported from other parts of the world, which causes significant yield loss up to 100%. R. solani can survive in the soil for several years and able to infect plants belonging to more than 32 families, including many economically important monocots and dicots plants. The severity of the disease favoured by humid weather with temperature around 28°C, poses challenge to maize growers due to its soil borne nature and lack of resistance cultivars. It is indicated that none of the disease management approaches are effective against BLSB. Banded leaf and sheath blight is difficult to control through either fungicide or crop rotation alone. A number of quantitative trait loci (QTLs) controlling BLSB have been identified that would help the development of maize hybrids resistance to this disease. Management of BLSB requires an integrated approach based on the knowledge of each stage of the disease and molecular aspect of maize defence responses against R. solani. Mention conclusion statement and novelty of the work. The present review summarizes consolidated information on distribution, yield loss, symptoms, pathogen life cycle, epidemiology, genetic structure of the pathogen population, molecular aspect of pathogenicity and its integrated management through cultural, biological, chemical and genetic means. The consolidated knowledge presented in this review should help better disease management and reduce crop yield loss due to banded leaf and sheath blight pathogen