- Sheath rot affects the upper leaf sheaths, which encloses young panicles.
- The lesions are oblong to irregular in shape, and are 0.5-1.5cm long. The lesions may have brown margins and grey centre or uniformly grayish brown.
- Gradually lesions enlarge and cover entire sheath.Whitish mycelium can be seen in the centre of the lesions on the inner side of the affected sheath.The developing panicles are choked within the rotten sheath.
- Sometimes partial emergence is also noticed. The resulting grains will be chaffy or poorly filled, shriveled and discoloured.
Mark 4 one square meter plots in the field at random. Select 5 hills at random from each plot. From this calculate the total number of tillers and the tillers showing the symptoms of sheath rot. Estimate the % infection.