Bacillus megaterium promotes both growth of seedlings in the laboratory and nodulation of the yardlong bean (Vigna unguiculata subsp. sesquipedalis) in the pot under outdoor condition

The culture of Bacillus megaterium was prepared using simple culture technique in the laboratory. The aerated culture of this bacterium using Knorr^® as the medium yielded the bacterium at 1.3×10⁵ CFU mL^‑1; while, the bacterial culture using shaken method produced 1.2×10² CFU mL^‑1 after four days of cultivation. This simple preparation of the culture was used to soak the seeds of the yardlong bean (Vigna unguiculata subsp. sesquipedalis). In the sand tray test in the laboratory, B. megaterium had potential to promote growth of the yardlong bean when the dried biomass of the seedlings was assessed. Seeds of the yardlong bean were soaked with the bacterial culture before they were sown to the growing medium in the pots. The bacterial culture was applied to the seedlings of the yardlong bean by drenching the growing medium under outdoor condition. Based on observation, the bacterium induced early flowering and increased yield of the yardlong bean. The yardlong beans which received the bacterial culture through drenching had number of nodules higher than other treatments with statistically significant difference. Diluted aerated-culture of B. megaterium has potential for improving growth and yield of yardlong bean in the farm.