ABSTRACT

Studies were carried out on the effects of different agro-wastes (saw dust, sugarcane baggasse and maize stalk) individually and in combination on the growth, yield, biochemical composition and polysaccharide degradating potentials of Pleurotus ostreatus and Pleurotus pulmonarius at the Department of Plant Health Management, MOUA Umudike, Abia State. The design was completely randomized design (CRD), replicated four times. Data were subjected to Analysis of Variance (ANOVA) and means separated using least LSD at 5% level of probability. Number of fruit bodies of P. ostreatus after three flushes was highest with MS substrate (72.7), followed by MS+SB substrate (70). The SD+MS substrate supported mushrooms with the best stipe length (5.4cm), followed by MS+SB (4.3cm) substrate. The MS substrate produced P. ostreatus and P. pulmonarius with the best pileus diameter and also supported the heaviest fresh fruit body weights mushroom of 57.7g and 83g at average respectively. P. pulmonarius sustained the highest number of fruit bodies with MS substrate (96.0) followed by SD+SB. The biological efficiency results indicated that the substrates were effectively utilized to varying degrees by the oyster mushrooms. For P. pulmonarius and P. ostreatus, MS+SB substrate was best utilized and recorded the highest biological efficiency. The highest nutrient value of P. ostreatus was obtained from mushrooms on SD substrate (27.17mg/100g) followed by those on SB + MS substrate (27.15mg/100g) whereas P. pulmonarius had the highest nutrient composition with SB+MS substrate (27.19mg/100g) while P. ostreatus and P. pulmonarius had the highest phytochemicals with SD substrate (1.44mg/100g) and SB substrate (1.35mg/100g) respectively. The MS substrate recorded the highest minerals (80.45mg/100g) in P. ostreatus followed by SD+MS substrate (79.99mg/100g). SD substrate was the best in enhancing the mineral content of P. pulmonarius (83.29mg/100g). The highest mean vitamin composition of P. ostreatus was in SB substrate, (3.89mg/100g) followed by SD+SB substrates (3.52mg/100g). P. pulmonarius grown with SB substrate recorded the highest vitamin content (4.08mg/100g). The result on the effect of substrates on heavy metal composition of P. pulmonarius  showed no significant (p > 0.05) differences among the substrates except with SB substrate that recorded the highest Zinc content. The average heavy metal content of P. ostreatus was highest with SB substrate (0.42ppm) followed by SD and SB+MS substrates recording 0.38ppm each and the least was recorded with MS substrate (0.31ppm). Polysaccharide degrading potential of P. ostreatus was highest with SB substrate (37.86%), followed by SD+SB substrate (31.76%) and SD substrate (27.56%). The highest polysaccharide degrading potential of P. pulmonarius was recorded with SB substrate (28.29%) followed by MS substrate (20.54%). This study revealed that SD, SB, MS and their different mixtures are good substrates for the production of mushrooms. Both P. pulmonarius and P. ostreatus showed that MS+SB substrate was better utilized by the fungus. The MS, SB and SD+SB substrates could be used as potential substrates for the production of P. ostreatus and SB, SD, MS+SB and SD+SB substrates for P. pulmonarius production since they enhanced their nutrient, vitamins and mineral contents as well as bioactive compounds.