Influence of Temperature and Relative Humidity on the Growth, Sporulation and Pathogenicity of Beauverianrnr. bassiana

Among the five different temperature conditions tested; radial growth, biomass production and sporulation were greater at 25°C foHowed by 30 and 20De. Similarly susceptibility of third instar shoot borer (Chilo infuscatellus Snellen) larvae to fungal infection was higher when the larvae were held at 25°C after treatment. Among the 5 relative humidity (RH) levels tested at 25°C, the radial growth of the fungus was maximum at 90 per cent RH, whereas biomass production and sporulation were greater at 100 per cent RH. Higher mortality of borer larvae occurred at 100 and 90 per cent RH levels and the susceptibility decreased as the RH increased.