The effectiveness of biopesticide formulation Bacillus subtilis BNt8 as biocontrol agent of banded leaf and sheath blight (Rhizoctonia solani) disease on corn (Zea mays L.)

The role of synthetic pesticides to control banded leaf and sheath blight (BLSB) disease on corn are still very dominant, therefore still many efforst are needed in order to minimize the negative impacts. One way of controlling this disease more prudent at this time is the use of antagonistic bacteria as the biological control agent like Bacillus subtilis. The present study aimed to determine the effectiveness of a biopesticide formulation B. subtilis BNt8 on a different frequency and dosage to control BLSB disease (Rhizoctonia solani) on corn plants in the field. Another effect of the application of a biopesticide formulation of B. subtilis can be observed by monitoring the growth of plants. The research was conducted in the plant pathology laboratory and greenhouse of Indonesian Cereals Research Institute at Maros and in Bajeng experimental farm. In the field study, the treatments were arranged in randomized factorial design. Result of experiment showed that in vitro test, treatment with concentration 2 g/L provided relatively better levels of inhibition in suppressing the development of fungal mycelia of R. solani. In green house trial, seed treatment with concentrations of 3% was able to suppress BLSB disease, so it can be recommended for field tests. In the field trial, application intervals of 3 weeks tend to give a better effect in suppressing disease and improve yields. Applications of biopesticide formulation B. subtilis could suppress BLSB disease up to 18.5% and the yield potential to reach 5.3 tons/ha.