Occurrence of False Floral Smut in Sugarcane Inflorescence and Associated Weather Variables

During the survey and monitoring, a disease affecting sugarcane arrows was noticed. Sugarcane inflorescence with symptoms was collected from the germplasm maintained at ICAR-SBIRC, Kannur. The disease was observed in 2017, 2018 and 2021. The length of affected grains varied from 3 to 3.5 mm, an average of 3.2 mm and the width varied from 1 to 1.5 mm, while regular grains showed no change in length, and the width was only 0.5 mm. The affected grains were somewhat bulged and black. Conidia of Epicoccum andropogonis and Claviceps purpurea were observed when examined under a light microscope, whereas, in culturing, the affected grains yielded only E. andropogonis. The morphological characteristics of E. andropogonis were studied in vitro. The shape, color and size of the fungus conidia resembled the conidia in vitro culture media. This fungus was identified based on molecular data from the ITS-rDNA sequence, and this is the first report of false floral smut occurrence on germplasm maintained at SBIRC, Kannur. A total of 24 clones were affected, including a clone WL 08-259 of waterlogging trial in 2021. The clones were categorized based on the number of spikelets affected. All the Saccharum species clones, 287 foreign hybrids and 393 Indian hybrids clones were found to be resistant. The 18 clones of Indian hybrids and two foreign hybrids were found to be highly susceptible, and three clones of Indian hybrids were moderately susceptible.