LAUSR

Red rot of sugarcane is caused by Colletotrichum falcatum. A recent survey, however, indicates that other fungal species may be associated with red rot-infected sugarcane leaves. This study 1) investigates the cause of the red rot-like symptoms using a polyphasic approach, 2) determines the pathogenicity of the fungi in sugarcane leaves and infection potential in leaves and stalks in detached-plant assays, and 3) assesses their effect on the stalk sugar level. Based on combined morpho-cultural and molecular characterization, the associated fungi were identified as Fusarium sacchari and F. proliferatum. The two Fusarium species induced red rot in leaves and stalk, as did the C. falcatum control isolate. Stalks infected with the two Fusarium species had reduced sugar level after 14 days, compared to the healthy stalk checks. To our knowledge, this is the first record of Fusarium species associated with red rot in sugarcane. These results suggest that the causal agent of red rot in the field is likely to be considered when developing or implementing disease control measures. Further, sugarcane breeding programs for red rot resistance would be likely aimed at all known causal pathogens.