grow the inoculum (R. solani) on plant material like straw of typhus plant tie it to the stem just at the soil level. You can grow on barley grains and keep it near the plant or in the soil directly.
Hi, I agree with the two answers given earlier. But, you can also try maize meal medium or sorghum grain based medium for the mass multiplication of inoculum which can be used @ 10g/ kg soil to induce disease. I hope you will find the procedure in papers to prepare the same.