Disease scenario and management of major sugarcane diseases in India

Abstract

Sugarcane is a major commercial crop grown in tropical and subtropical regions of the country. During the last 100 years, the country has witnessed epidemics of various diseases like red rot, smut, wilt, rust, leaf scald and yellow leaf (YLD). The damage caused to sugarcane during each epidemic would vary depend upon the nature of disease and spread of the affected varieties. Many sugarcane varieties were replaced due to their breakdown to a new disease or to a new pathogenic strain. Still, red rot remains to be the major disease of sugarcane in the country and wilt and smut are the other major diseases seriously affecting cane production in India. In addition, the new disease YLD causes serious damage to cane productivity in many states. Severity of grassy shoot disease, pokkah boeng and rust is also growing in many parts of the country. Propagation of sugarcane through vegetative cuttings favours spread of diseases through planting materials. Primary transmission of different diseases through seed canes poses serious threat to sugarcane growth and performance. Disease resistant varieties play a crucial role in managing many of the diseases in sugarcane and several varieties have been developed to manage the diseases in the past. In addition, different agronomical approaches and physical method like heat therapy are being effectively used to manage the diseases in sugarcane. Recently, multiplication of sugarcane through tissue culture is being advocated to produce virus and phytoplasma disease-free planting materials. Among serological methods, ELISA and tissue-blot technique have become very popular and largely used for routine detection of bacterial, phytoplasmal and viral pathogens in sugarcane. Molecular techniques like polymerase chain reaction (PCR), reverse-transcriptase (RT)-PCR and nested PCR assays are most sensitive than the serological techniques especially to detect sugarcane viruses and phytoplasmas which occur at low concentrations. Use of disease resistant varieties along with healthy seed nursery programmes would form the basis to successfully manage the diseases in sugarcane