Sugarcane Rust: Changing Disease Dynamics and Its Management

Abstract

Sugarcane (Saccharum officinarum L.) is grown in both tropical as well as sub tropical regions and the diseases are one among the major constraints in crop production. The severity of the diseases are mainly influenced by the varieties, crop stage and major weather parameters such as temperature and precipitation. Apart from stalk pathogens such as red rot, wilt and smut, the foliar pathogens of sugarcane especially rust causes substantial yield losses due to disease epidemics in susceptible varieties. The disease has been reported in most of the sugarcane growing countries especially in tropical regions. The uredospores of rust are carried away in wind current and are capable of causing fresh infection in sugarcane plants across the fields. In India, the rust severity is restricted to peninsular regions in Tamil Nadu, Karnataka, Andhra Pradesh, Telangana, Gujarat and Maharashtra and sub tropical states are relatively free from rust diseases due to unfavourable climate for rust pathogens. Though the disease has been reported more than 100 years ago in India, information on sugarcane rust is scanty hence an attempt has been made to review sugarcane rusts and their epiphytotics in the past and their impact on country's economy and importance of rust resistant varieties in containing the disease. Major emphasis was given on the pathogen biology, variability and development of new races in sugarcane growing regions, influence of weather factors in host pathogen interaction and breakdown of resistant varieties, trans-oceanic movement of uredospores, sources of rust resistance among world sugarcane germplasm and Bru genes and their contribution in brown rust resistance and management of sugarcane rusts using chemicals and host resistance.