Dulay, Rodante J.2026-06-052026-06-052022-05Dulay, R. J. (2022). Performance of eggshells to mycelial growth and yield of mushroom. [Unpublished Undergraduate Thesis]. Don Mariano Marcos Memorial Stae University - North La Union Campus, Sapilang, Bacnotan, La Union. Lakasa ti Sirib, DMMMSU Institutional Repository.https://lakasa.dmmmsu.edu.ph/handle/123456789/1708Eggshells are often discarded as waste, but can be used for mushroom production because of its calcium carbonate content. In this study, the performance of eggshells to mycelial growth and yield of mushroom is determined. The study was conducted using experimental design laid through Completely Randomized Design (CRD). There are four (4) treatments with 3 replicates each and each treatment with 5 samples, with a total of 60 samples. The treatment resulted in the slight reduction of pH values (8.0) of the substrate. The temperature is found to be higher than the optimal temperature while the humidity is mostly lower than the optimum range. The full colonization of mycelial growth is noted after 28 days in all treatment. The first flush of fruit appeared in T0 and T2 after 32 days, while the largest yield was noted in T3. Results showed the potential of eggshell in enhancing the mushroom cultivation. Keywords: eggshells, mushroom, mycelial growth, yielden-USThesis