Shiitake culture in sawdust is a widely applied method, which can supplement the disadvantages of costly and time consuming oak log cultivation. In sawdust cultivation, browning of surface mycelia is an important stage for the productivity and longevity of sawdust media. Surface browning forms protection coat for the substrate, which can block the invasion of outer pathogens and suppress water evaporation in the substrate. We controlled different light source (red LED, white LED, blue LED, and fluorescent light) with different intensity of illumination (1.5, 10.5, 20.5 μmol/m2s for LEDs and 10, 100, 300 lux for fluorescent light) to induce browning. Lights were treated with 1 hour on/ 1 hour off cycle maintained in a controlled room with 20oC temperature, 60% humidity, and 1200 ppm CO2 atmosphere concentration for 67 days. Browning effect differed from the source and intensity of illumination. Browning was most effective in 1.5 μmol/m2s for blue LED. All light sources showed less browning in highest intensity of illumination, which indicates that higher than 20.5 μmol/m2s for LEDs or 300 lux for fluorescent light are not effective. After harvesting fruit bodies, we measured their weight, length and width of pileus and stipe, chromaticity, and hardness. Treatment with 1.5 μmol/m2s blue LED produced the best harvest with highest average individual weight (21.2g), stipe length (30.8 mm), and hardness (377.9 g) with fine length and width of pileus, and chromaticity. This results indicate that 1.5 μmol/m2s blue LED showed the best browning effect which resulted in the best harvest yeild.

Shiitake culture in sawdust is a widely applied method, which can supplement the disadvantages of costly and time consuming oak log cultivation. In sawdust cultivation, browning of surface mycelia is an important stage for the productivity and longevity of sawdust media. Surface browning forms protection coat for the substrate, which can block the invasion of outer pathogens and suppress water evaporation in the substrate. We controlled different light source (red LED, white LED, blue LED, and fluorescent light) with different intensity of illumination (1.5, 10.5, 20.5 μmol/m2s for LEDs and 10, 100, 300 lux for fluorescent light) to induce browning. Lights were treated with 1 hour on/ 1 hour off cycle maintained in a controlled room with 20℃ temperature, 60% humidity, and 1200 ppm CO2 atmosphere concentration for 60 days. Browning effect differed from the source and intensity of illumination. Browning was most effective in 1.5 μmol/m2s for red and blue LED. All light sources showed less browning in highest intensity of illumination, which indicates that higher than 20.5 μmol/m2s for LEDs or 300 lux for fluorescent light are not effective. After harvesting fruit bodies, we measured their weight, length and width of pileus and stipe, chromaticity, and hardness. Treatment with 1.5 μmol/m2s blue LED produced the best harvest with highest average individual weight (21.2g), stipe length (30.8 mm), and hardness (377.9 g) with fine length and width of pileus, and chromaticity. This results indicate that 1.5 μmol/m2s blue LED showed the best browning effect which resulted in the best harvest yield.