Influence of Selected Nigerian Agro-Waste Substrates on the Morphological Characteristics and Yield of Pleurotus pulmonarius (Fr.) Quél

Background and Objective: The use of locally available lignocellulosic substrates in mushroom production offers a sustainable approach to waste utilization and food production. However, substrate type and supplementation levels may influence fruit body yield and profitability in oyster mushroom production. The main objective of this study was to determine the effects of selected agro-wastes on the fruiting performance of Pleurotus pulmonarius. Materials and Methods: Coconut fiber (CF), Raphia palm inflorescence (RPI), and oil palm husk (OPH), supplemented with rice husk (RH) at 25% and 50% levels, were made in five replications of 150 g each and were pasteurized at 80°C for 2 hours. Each substrate was inoculated with 50 g of grain-based spawn and incubated in the dark during the spawn run. Data were analyzed using ANOVA, and mean differences were separated using Duncan’s Multiple Range Test (DMRT) at the 5% significance level. Results: The shortest primordial formation time (18 days) was observed in 100% CF, while 75% CF recorded the longest (32 days). All OPH substrates (pH 10.3) failed to produce fruit bodies. The highest yield (438.0 g/kg) and biological efficiency (58.40%) were obtained from 100% RH, followed by 100% RPI (346.00 and 46.13%), whereas 75% CF recorded the lowest yield (108.0 g/kg) and biological efficiency (14.40%), with significant differences at p<0.05. Morphologically, 100% RPI produced the longest stipe (3.39 cm), while 75% RPI (6.65 cm), 50% RPI (6.39 cm), and 100% RH (6.78 cm) produced a larger pileus diameter and higher fresh weight. Results further showed weak to moderate correlations, indicating that an increase in SL is associated with an increase in CS, FBW, and FBN of the cultivated P. pulmonarius fruit bodies. Conclusion: The RH, RPI, and CF are suitable substrates for the cultivation of P. pulmonarius and are therefore recommended for commercial or large-scale mushroom production.