The studies were undertaken to find out the susceptible age of the host plant (Khejri), optimum inoculums load and inoculums age for maximum root rot development. Five days old ‘Khejri’ seedlings exhibited 80 per cent mortality which was significantly higher than other treatments. With the increase in inoculums load, there was a corresponding increase in disease incidence. The seedlings showed maximum mortality when inoculated with 20 days old oat seed sand culture. Young seedlings were more prone to disease than the older ones.