ABSTRACT

 The study was aimed at determining among the following: Cocos nucifera, fibre (CNF) Raphia vinifera head (RVH) and Elaeis guinensis head (EGH), supplemented with Rice husk (RH) at 25% and 50%. The best substrate for yield and nutritional composition of Pleurotus ostreatus var florida (Eger.) fruit bodies. The experiment consisted of 10 sample substrates: CNF100%, CNF75% and CNF50%. RVH 100%, RVH75% and RVH50%. Others include EGH100%, EGH75%, EGH50% and RH100%. The experiment employed Completly Randomized Design (CRD). These were collected and cut into sizes of 2-4cm and weighed dry. They were drained of excess water after composting for 2 days. Known weight of each substrate or supplementation was made in 5 replications and placed into a uniformly perforated 2.51itre transparent plastic bucket before pasteurization in a gas-heated metallic drum at 80°C for 2hrs and left over night to cool. 30g pure of mycelia culture (grain spawn) of P. ostreatus varflorida was used to inoculate the substrates in each bucket. The buckets were covered in the dark during spawn run in a well humidified cropping room. Results revealed that CNF 100% had the shortest time of pinhead initiation (18 days), while CNF 75% had the longest time (32 days). All the EGH substrates did not produce any fruit body as pH value of the substrate was high at 10.3. Rice husk 100% gave the best yield and biological efficiency (438.0g/kg and 58.40%) respectively, while CNF75% gave the lowest yield and BE (108.00 and 14.40%) respectively. Other results were significant at P<0.05. Dry powder samples of harvested fruit bodies and those of unused substrates were used to determine Proximate, vitamin, heavy metal, pH and bioactive compounds. One way ANOVA was used for data analysis and mean separation by Duncan multiple range tests at 0.05 level of significance. All unused substrates, showed that the quantity of  each nutrient affects that of mushroom significantly P< 0.05. The amino acid profile analysis revealed that 100%, followed by 50% concentration of each substrate contained higher amino acid contents than their supplementation at 25%. The cellulose, hemicellulose and lignin degradation of the substrates revealed that their reduction rate was highest in CNF but lowest RVH substrates. There was high level of correlation (r = 1.00) among Yield and BE, bioactive, mineral, proximate and heavy metal contents of fruit bodies of the affected substrates. It is therefore recommended that RH, RVH and CNF are good substrates for the cultivation of P. ostreatus var. florida fruit bodies. Further research based on pH optimization of EGH substrate should be embarked on.