Erlenmeyer flasks (250 ml) containing 100 ml of potato dextrose broth (PDB) were incubated with 1 cm2 discs of the actively growing mycelia of R. solani Q1. The inoculated flasks were incubated at 28 °C for 4 days without shaking. The mycelia were then collected by filtration through gauze and washed with distilled water.
The BIO product used in the experiments was obtained by aerobically fermenting a mixture of the amino acid fertilizer with N43 for 5 days at