Within 1-3 days of inoculation, leaves of sugarcane infected by B. sacchari exhibit lesions that begin as small reddish spots on both leaf surfaces. The spots become elliptical with the long axis parallel to the main veins. The margin is red to brown. The centre of the spot becomes grey or tan. The spots may run together and form long streaks. Sugarcane seedlings may be killed by blight 12-14 days after sowing from a top rot in severe infections.
Eyespot is transmitted by spores (conidia), which are produced abundantly on leaf lesions and are dispersed by wind and rain. Fungal spore germination is favored by high humidity and dew formation. Colonization is more rapid in younger leaves than older leaves. Transmission by seed piece does not occur. Mechanical transmission by equipment and by human activity is not an issue.
Unfortunately, there is no known alternative treatment against Bipolaris sacchari. We request you to get in touch with us in case you know of something that might help to fight this disease. Looking forward to hearing from you.
Always consider an integrated approach with preventive measures and biological treatments, if available. Foliar application 0.2% copper oxychloride or 0.3% mancozeb with 2 to 3 sprayings at an interval of 10 to 15 days. Spraying is to be done as per the severity of the disease.