Production of Plant Growth Hormones and Subtilin from Organic-Biodynamic Manures.
Karuppan Perumal V and Varadarajan Stalin. Shri Amm Murugappa Chettiar Research Center, Tharamani, Tamil Nadu, Chennai, 600 113, India
The green revolution forced agriculturist to explore natural way of agricultural inputs for sustainable crop production. The organic manures are economically sustainable amendment to the soil for irrigating crops and suppress plant disease by antagonistic activity. Microorganisms in the soils and organic manures contained plant growth promoting metabolites and also have antibacterial and antifungal properties. Based on this hypothesis, the present study focused on isolation of bacterial and fungal strains from twelve different composts namely vermicompost, NADEP compost, Cow Pat Pit manure (CPP), biodynamic compost, cow horn manure (BD 500), panchakavya, biodynamic herbal preparations such as BD 502, BD 503, BD 504, BD 505, BD 506, and BD 507. The cow pat pit manure contained three plant growth hormones such as IAA (28.6 mg/ Kg of manure), kinetin (7.6mg/ Kg of manure) and Gibberllic acid (23.6 mg/ Kg of manure) whereas the other manures did not contain Gibberlic acid. Biodynamic herbal preparations BD 504, BD 505 and BD 506 contained IAA, GA3 and Abscessic Acid (ABA). Among the 12 organic manures analysed for the enumeration of microorganisms, cow pat pit manure contained the highest bacterial load (4.8x106) per gram of manure and beneficial bacteria such as Rhizobium sp (1.9x106), Azospirillum sp (0.2 x106) and Azotobacter (0.8 x106) and fungi (2.5x106). Of the total 29 representative bacterial strains isolated from different composts, Bacillus subtilis was predominant in the cow pat pit manure. The water extract of organic manures had subtilin which intern suppressed the growth of different pathogenic bacteria such as Staphylococcus aureus, Escherichia coli, Micrococcus lutes, and Erwinia carrotovora. Among the organic manures tested for subtilin the cow pat pit (CPP) manure contained highest amount of subtilin (1.23 O.D at 560 nm). CPP manure maturation was analysed periodically for a period of 120 days. The growth (4.0x106) and subtilin production (1.078) by Bacillus subtilis during cow pat pit maturation were increased till 90 days. The cow pat pit manure will dual functions on crop and soil depending the manure maturation.The cow pat pit manure grown for 75 to 90 days is suitable for plant disesae resistance whereas the 120 days old manure is suitable for soil nutrient supplements. Positive relationships between production of plant growth hormones and subtilin in organic and biodynamic manures have not only supplied the available nutrients but also significant effects on crop growth and disease resistance.