The first symptoms appeared on the leaves. Elliptical brown spots were observed. The spots increased in size on
leaves. Gradually the colour of the spots changed to brownish black. The length of spots ranged from 0.2 to1cm (Figure 1).
Later the spots appeared on leaf sheath which were dark brown initially with yellow margin and the diseased sheath
became yellow and blighted. Initially these spots were similar to the ones on the leaf but later covered the whole leaf
sheath (Figure 2). Gradually the disease spread to the kernels. Glumes were discoloured and in severe infection, the rice
kernel showed black discoloration (Figure 3).
Micro-scopical examination revealed the presence of conidia of the fungus. The conidia were four celled and
generally curved, second cell larger with two middle cells darker than the paler end cells. Conidiophores were branched,
septate and dark in colour