Table 2 shows that pale green and lanky seedlings were found up to 1.0×107 conidia/ml
treated sets. Therefore, minimum effective level of inoculum potential for screening rice varieties
against bakanae disease was detected as 1.0×107 conidia/ml in this study. Disease intensity was
measured in terms of colour, lankiness, OGR and death rate that were found best in the highest
inoculum concentration (5.0×1010 conidia/ml). In artificial inoculation method of varietal
screening, higher inoculum concentration is necessary to ensure heavy disease pressure (Haque
et al. 1979).