SPENT MUSHROOM SUBSTRATE AS A MEDIA FOR LEAFY VEGETABLE CULTIVATION IN URBAN AGRICULTURE

The main objective of this study was to investigate the yield performance and disease suppression ability of SMS on leafy vegetable cultivation, i.e. Mukunwenna (Alternathera sessilis). A field experiment was carried out from July to December 2011 at the research field of Agricultural Research Station, Telijjawila in Matara district located in Low country intermediate zone (IL1) of Sri Lanka. Simultaneously an in vitro experiment carried out at the Department of Agricultural Biology, Faculty of Agriculture, and University of Ruhuna, Sri Lanka to study the antagonistic effect of SMS on red leaf spot disease of Mukunuwenna. The field experiment was arranged in Randomized Complete Block Design (RCBD) with four treatments and four replicates. The data obtained were tabulated and analyzed subjected to the Analysis of Variance (ANOVA) procedure of Statistical Analysis System (SAS). Results clearly showed that the total fresh weight of Mukunuwenna was not significant different (p<0.05) among different treatments tested. The in vitro study conducted using 72 bacterial isolates obtained from the SMS samples revealed that the ability of 35 of the 72 unidentified bacterial isolates significantly inhibit the Cercospora, i.e. causal organism of the red leaf spot disease in Alternathera sessilis. The study enumerated the vast potential of SMS as an alternative growth substrate for a subsequent cultivation of leafy vegetables particularly for urban agriculture where solid waste disposal is problematic due to limited land availability