Incidence, symptomatology and transmission of sugarcane grassy shootdisease in Assam, India

Abstract

A roving survey was conducted during 2015 and 2016 to study the incidence, symptomatology and transmission of sugarcane grassy shoot (SCGS) disease in the sugarcane growing areas of four districts of Assam, viz. Biswanath, Golaghat, Sonitpur, and Nagoan. Major symptoms observed in the fields were the production of narrow and chlorotic leaves ranging from pale yellow to completely white color, the development of chlorotic streaks in leaves, unproductive tiller proliferation and the bushy appearance of the infected stool, with thin and non millable canes with short internodes. The average disease incidence ranged from 10-22%. The transmission of the disease was attempted by different methods. Out of five predominant leafhopper species (Cofana unimaculata, Exitianus indicus, Hishimonus phycitis, Nephotettix nigropictus, Orosius albicinctus) collected and identified from the sugarcane fields, in all the four districts, only E. indicus was successful in transmitting the SCGS disease. The disease was also transmitted by the setts collected from sugarcane grassy shoot symptomatic canes and by dodder.