Here are the access points to research briefs from ICRISAT (India) regarding microbial assays of BD preparations. The study found BD preps contain antagonistic bacteria which are suppressive to Fusarium pathogen and infective to Helicoverpa larvae.
Steve Diver ==================================================== Isolation of potentially antagonistic bacteria from special composts used by organic farmers http://www.icrisat.org/text/research/nrmp/researchbriefs/rup2.asp Excerpt: Some organic farmers in Karnataka and Tamil Nadu states of India, who use six different composts (popularly known as Biodynamic or BD preparations), when visited in 1998, reported lower incidence of diseases and insect pests than neighboring "mainstream" farmers. Further queries revealed that each compost was prepared using a different protocol, all proposed in 1924 by Rudolf Steiner (Proctor, P., Cole, G., Lyons, T., in Grasp the Nettle: Making Biodynamic Farming and Gardening Work, Random House, Ltd., New Zealand, 1997, 176 pages). These preparations were available commercially in Tamil Nadu. We counted microbial population in - different BD preparations after developing a method of counting antagonistic bacteria [see details]. Fusarium solani (causes black root rot of chickpea) was used as test organism. The colonies with maximum level of suppression of the fungus on a given culture plate were isolated. A total of 28 potentially antagonistic bacteria were from the BD-preparations. Purified isolates were characterized for Gram reaction, sporulation, and tolerance to desiccation. Twenty seven of the 28 isolates (96%) from the six BD preparations formed spores. All spore-forming bacteria survived for at least 108 days in a desiccator; some survived for at least 17 months (studies continuing). Antagonists surviving desiccation for long periods could be used in dry formulations as biocontrol agents. Some of the isolates showed suppression of disease causing fungi in plate culture (Figure 1). For More Details Click Here: A new method for identification and enumeration of microorganisms with potential for suppressing fungal plant pathogens http://www.icrisat.org/text/research/nrmp/researchbriefs/rup1.asp Excerpt: The organic farmers in Karnataka, India, when visited in 1998, also stated that their crops generally had less disease incidence than those of their neighbors following mainstream agriculture. It was guessed that soil of organic farms and some of the alternatives to chemicals used by them had high population of microorganisms that suppressed the growth of disease causing fungi. An urge to verify this led us to devise a laboratory method of rapidly identifying microorganisms with potential to suppress plant pathogenic fungi (antagonistic microorganisms) in the presence of other microorganisms and is described here. Source: ICRISAT-NRMP: Natural Resource Management Program | Research Briefs http://www.icrisat.org/text/research/nrmp/researchbrief.asp Microorganisms antagonistic to disease causing fungi are an important component of integrated disease management (IDM). We identified 28 strains of antagonistic bacteria from herbal composts used by organic farmers in India. The bacteria were identified (due to presence of a halo around their colony) using Two-layer method that allowed counting of their population in a compost sample. The method used Fusarium solani as a test host. Some of the isolates suppressed other disease causing fungi such as Sclerotium rolfsii when evaluated using Dual culture plated. Some also killed larvae of Helicoverpa armigera (pod borer) in laboratory studies. Twenty seven of the 28 were spore forming. Home: ICRISAT-NRMP: Natural Resource Management Program http://www.icrisat.org/text/research/nrmp/nrmphome.html ==================================================== ====================================================
