Abstract
Two isolates of Rhizoctonia solani (KFRI Acc. No. 766 and 783) at two levels (1: 50 and 1: 200 on w/w basis, inoculum to soil) affected significantly incidence and spread of web blight disease, within and among Albizia falcataria seedlings of two age groups (60 and 75 days old) . Of the five developmental stages of web blight, initiation (disease development stage I), primary spread of the disease from stem to first basal leaf in individual seedlings (stage II) and mortality of affected seedlings (stage IV) were significantly influenced. Though low inoculum level was more efficient in causing the disease and promoting its initial spread, the two inocula did not differ in causing death of of seedlings. None of the three factors, however, showed any significant influence on upward spread of mycelium from first basal leaf in individual seedlings (stage III) and also on lateral spread from one seedling to another (stage IV) . The most susceptible combination of isolate, inoculum