This study was conducted to investigate the optimum supplementation ratio when replacing cotton seed meal with rapeseed meal for cultivating oyster mushrooms. The chemical properties among the treatments were pH 4.5~4.7, total carbon content was 46.3~46.5%, total nitrogen content was 1.6~1.7%, and carbon-nitrogen ratio was 27.0~27.8. These did not differ significantly from the control. Mycelial growth was 85.1 mm (Heuktari), and 72.8 mm (Suhan-1Ho) in medium containing 5% rapeseed meal, with no significant difference in mycelial density between cultivars. Fruiting body characteristics are as follows: In 'Heuktari', the color of the pileus was darker than control with an L value of 32.5, and pileus thickness and diameter were 3.2 mm and 27.6 mm, respectively. Stipe length and diameter were 86.0 mm and 9.1 mm, respectively. Valid stipe number per bottle (1,100 cc) was 25.9, and a yield of 189.7 g/1,100 cc was recorded in mixed medium containing 5% rapeseed meal (higher than control). In mixed medium containing 10% rapeseed meal, the yield was 184.5 g/1,100 cc (comparable to control). In 'Suhan-1Ho', supplemented with 5% rapeseed meal, pileus color was darker than control color, with an L value of 28.8. Pileus thickness was 4.5 mm. Stipe diameter was 12.3 mm (higher than control), and yield was 145.5 g/1,100 cc (comparable to control).

This study was conducted to investigate the optimum additive ratio of barley flour when used instead of cotton seed meal for the cultivation of oyster mushrooms. Mycelial growth was the fastest to 11.4 cm in medium containing 5% barley flour and to 9.0 cm in medium containing 30% barley flour. The mycelial density was slightly lower at 5% and 10% of barley powder addition, but there was no significant difference between the other treatments. The yield of the fruiting bodies was 158 g/850 mL, which was highest on treatment with 10% barley flour as a substitute for cotton seed meal. However, this was lower on treatments with only barley flour than in the control (156 g/850 mL). The diameter of the pileus and the hardness of stipes were highest with 10% barley flour and 10% in cotton seed meal, respectively. The L value was highest with 10% added barley flour, but the a-value and the b-value were not significantly different between treatments. The pH of the mixed media before inoculation with Pleurotus ostreatus was 4.7–5.0, and the total nitrogen content was 1.7–2.2, which was slightly lower than that of the control. The total carbon content was 44.6–45.0, which was not significantly different from that of the control. However, the content of trace elements such as Cu and Fe was lower than those of the control.