World Journal of Microbiology and Biotechnology

, 24:2499

Water-soluble granules containing Bacillus megaterium for biological control of rice sheath blight: formulation, bacterial viability and efficacy testing

  • Amornrat Chumthong
  • Mana Kanjanamaneesathian
  • Ashara Pengnoo
  • Ruedeekorn Wiwattanapatapee
Original Paper

DOI: 10.1007/s11274-008-9774-7

Cite this article as:
Chumthong, A., Kanjanamaneesathian, M., Pengnoo, A. et al. World J Microbiol Biotechnol (2008) 24: 2499. doi:10.1007/s11274-008-9774-7

Abstract

Endospores of B. megaterium were formulated in granule formulations with sodium alginate, lactose and polyvinylpyrrolidone (PVP K-30) by the wet granulation technique. The granule formulation exhibited good physical characteristics, such as high-water solubility and optimal viscosity, that would be suitable for spray application. The bacteria remained viable in the dry granule formulation at 109 c.f.u./g after 24 months storage at room temperature. Under laboratory conditions, aqueous solutions of the formulation showed high activity against mycelial growth of R. solani (99.64 ± 0.14% mycelial inhibition). High viability of the bacterial antagonist on leaf sheath and leaf blade at day 7 after spraying with the formulation was observed (approximately 106 c.f.u./g of plant). Application of an equivalent number of un-formulated endospores resulted in much loss of the bacterial endospores even 1 day after application. In a small pilot field study, an aqueous solution of the formulation (3%w/v) applied by spraying at days 1, 5 and 10 after pathogen inoculation of the rice plants was more effective in suppressing rice sheath blight disease than one application of a fungicide (Iprodione) at day 1. Additionally, rice plants sprayed with the aqueous solution of the granule formulation had higher panicle and whole kernel weights than those of fungicide-treated and control (untreated) plants.

Keywords

Bacillus megateriumBiological controlFormulationGranulesRhizoctonia solaniRiceSheath blight disease

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • Amornrat Chumthong
    • 1
  • Mana Kanjanamaneesathian
    • 2
  • Ashara Pengnoo
    • 3
  • Ruedeekorn Wiwattanapatapee
    • 1
  1. 1.Department of Pharmaceutical Technology, Faculty of Pharmaceutical SciencesPrince of Songkla UniversityHat Yai, SongkhlaThailand
  2. 2.Plant Production Technology Program, Faculty of Animal Sciences and Agricultural TechnologySilpakorn UniversityPhetchaburiThailand
  3. 3.Department of Earth Science, Faculty of Natural ResourcesPrince of Songkla UniversityHat Yai, SongkhlaThailand