Abstract: Pot experiments were conducted to study the effects of varied doses of Bacillus subtilis applied in the soil on the above-ground growth and chlorophyll content of Myrciaria cauliflora Berg that grew on it. The results showed all the tested applications of the microbial material increased the plant height, stem diameter, crown width, number of new shoots on main branch, longest main branch and chlorophyll content of M. cauliflora over control. When 3 g of B. subtilis was added to the soil in a pot, the most significant effects were observed. It was postulated that 900 to 1 800 g per acre of the application in the field would deliver the most desirable effect for M. cauliflora cultivation.