To reduce the production cost of Pleurotus giganteus and to valorize agricultural waste, this study investigated the effects of substituting cottonseed hull with corn cob (a major lignocellulosic by-product of maize production) on the mycelial growth, agronomic traits, nutrient composition, commercial quality, and economic benefits of P. giganteus ‘Shenxun No.1’. The aim was to verify the feasibility of this substitution and screen optimal substrate formulations for industrial cultivation. Four substrate formulations with corn cob substitution ratios of 0% (T1), 15% (T2, control), 30% (T3), and 45% (T4) were designed, while adjusting cottonseed hull proportions to 45%, 30%, 15%, and 0%, respectively. Mycelial colonization performance, fruiting body agronomic traits (yield and cap/stipe characteristics), nutrient contents (crude protein, crude fiber, etc.), and commercial traits (marketable yield and production cost) were systematically determined and analyzed. The results showed that corn cob content exceeding 15% prolonged the substrate bag colonization time by 5–7 days, but T4 (45% corn cob) resulted in the densest mycelia with excellent structural development. In terms of fruiting bodies, T4 exhibited the highest yield in the second harvest flush and the highest total yield across three flushes. Nutritionally, crude protein content of fruiting bodies decreased by 10.48% in T4 compared to T1, while crude fiber content increased with rising corn cob proportion; no significant difference in crude polysaccharide content was observed among formulations. Importantly, corn cob substitution did not impair the commercial traits of fruiting bodies, and T4 achieved the lowest material cost per bag (0.78 CNY) with an optimal cost–benefit ratio. In conclusion, corn cob is a viable and cost-effective substitute for cottonseed hull in P. giganteus cultivation, and the 45% substitution formulation (T4) is recommended for industrial production due to its superior yield performance and economic benefits. This study provides a theoretical basis for sustainable utilization of agricultural waste and optimization of P. giganteus cultivation systems.
Zhang et al. (Mon,) studied this question.