Shelf-life of Bacillus subtilis B298 inclusion in biopesticide microencapsule formula and its efficacy in suppressing anthracnose disease on chili

Abstract

Bacillus subtilis B298 is an antagonistic bacterium isolated from the rhizosphere of potatoes. It is capable in controlling diseases both caused by fungi and bacteria. Inclusion of B. subtilis B298 in biopesticide microencapsule formula (BMF) is an effort to extend its shelf life, which maintain its stability and relatively more resistant to environmental change conditions. This study aimed to determine the shelf life of B. subtilis B298 in BMF, and its effectiveness in BMF to suppress chili anthracnose disease. Application of B. subtilis B298 in BMF was conducted by chili seed coating for 24 hr, after seed sowing the biopesticide was applied again by watering the roots of plants, i.e. 10, 20 and 30 d after planting. The experiment was arranged in a completely randomized block design with 4 treatments (control, B. subtilis B298 BMF, fungicide and combination of B. subtilis B298 BMF and fungicide), each treatment was repeated 6 times. Variables observed were; B. subtilis B298 population in the BMF, the disease intensity and infection rate by Colletotrichum sp. The study showed that B. subtilis B298 in BMF was capable to survive for 5 wk with a population of 14.4 107 cfu/g and suppressed chili anthracnose by 53.71%.