An Eco-Biological Approach for Resource Recycling and Pathogen (Rhizoctoniae Solani Kuhn.) Suppression

Composting of coffee husk, coir pith and cow manure is carried out in bags with Trichoderma viride as inoculant. Vermiconversion of these is achieved by top load mechanism in a vermireactor using Eudrilus eugeniae. Both vermicompost and compost have aided in neutralizing the high acidic (pH-5.7-6.5) content of pure coffee husk and cow manure. Among the available nutrients, nitrogen content in composted end products of cow manure was 195 mg/kg, in coir pith 193.88mg/kg and in coffee husk it was 240.47mg/kg and in vermicomposted end products of cow manure it was 165.6 mg/kg, in coir pith it was 240mg/kg and in coffee husk it was 248.10mg/kg. Available phosphate in cow manure was 180.5mg/kg, in coir pith it was 157.14mg/kg and in coffee husk it was 275.52mg/kg of the composted end products and in vermicomposted end products of cow manure it was 190.4mg/kg, in coir pith it was 120.96mg/kg and in coffee husk it was 185mg/kg. Similarly available potassium was 255mg/kg, 263.37mg/kg and 317.04mg/kg respectively in composted end products of cow manure, coir pith and coffee husk and in vermicomposted end products it was 129mg/kg, 421.6mg/kg and 89.9mg/kg respectively. Nitrogen content was relatively high (248.10 mg/kg) in coffee husk vermicompost, available phosphate content was high (275.52 mg/kg) in coffee husk compost and available potassium was higher (421.6 mg/kg) in coir pith vermicompost. Extracts of composted and vermicomposted coffee husk, coir pith and cow manure were evaluated individually for suppression of pathogen Rhizoctonia solani. Pathogen suppressive property against R.solani was observed at 12hr, 24hr, 48hr and 72hr intervals. The percentage of growth inhibition was higher (60.55%) after 72hrs in the media amended with the extracts of coir pith vermicompost (CPVC) followed by extract of coffee husk vermicompost (CHVC)(46.11%). Pathogen suppression by cow manure vermicompost (CMVC) though initially was 16.18% at 48hrs, it was not retained and by the end of 72 hrs full development of the pathogen was observed in both the CMVC and that of control which consisted of media amended with only water. However inhibition by the composted end products of coir pith was relatively less (40.85%) as well as that of cow manure (15.54%) and coffee husk (50.85%) by 24 hrs. The ability to suppress the growth of R.solani by coir pith vermicasts can be attributed partly to higher potassium content, which helps in the absorption of plant nutrients as well as the high nutrients (nitrogen and phosphates) available leading to growth promotion and thereby disease resistance. Neutral pH of the soil also aids in the adequate absorption of nutrients. This paper presents a new approach in the characterization of physicochemical properties of the recycled products and their pathogen suppressive effect.