Cultivation Processes and Yield of Lentinula edodes on Surface Sawdust Bed

The process of cultivation and production of oak mushroom (Lentinula edodes (Berk.) Pegler) on sawdust surface beds were investigated. Sawdust surface bed cultivation is the method by which oak mushrooms are cultured and produced on sterilized sawdust surface bed without using bags. The bed was made by inoculating with 3 to 1 ratio of bed sawdust to oak mushroom mycelial inoculum. The sawdust bed medium with 65% water content was pasteurized at 65oC, inoculated with sawdust spawn and spread on the surface on vinyl film in cultivation shed. During 78 days of cultivation period, water content in the medium varied from 61 to 72%, its pH decreased from 5.6 to 3.9~4.6 and ergosterol concentration increased to 0.33~0.59 microgram/g. CO2 concentration in the medium rapidly increased to 8.06% in two weeks. In seven weeks the medium surface started browning and CO2 concentration increased to about 5.63%. Until 11th week the CO2 concentration was maintained at 6~7%. After removing the plastic cover on the bed for ventilation in 12 weeks, CO2 within the bed reduced dramatically to 1.5%. In the cultivation shed the internal temperature was 7.1~29 Celsius and humidity was 27.3 to 100%, while bed temperature ranged 11.6~30 Celsius. Oak mushroom fruiting started from late July, in 120 days after bed establishment in late March and continued for approximately 100 days until early December with eight cycles of irrigation treatment. The mushroom yield of the eight cycles were 288~352 kg during the 1st (7/29~8/4) to 3rd cycle (9/3~9/7), 800 kg at the 4th cycle (9/19~9/24), 1,296~1,853 kg during 5th (10/3~10/ 8) to 7th cycle (4.11~11/9) and 990 kg at 8th cycle (11/23~12/7). Total production was approximately 7.4 tons from 33.0 tons of oak sawdust medium, thus harvest efficiency of the mushroom production was approximately 22.4%.