This study was performed to investigate the causes of bacterial brown blotch in Agaricus bisporus by analyzing environmental factors using sensors and growth factor characteristics. We found no direct correlation between the CO2 concentration and bacterial brown blotch among the evaluated cultivation environmental factors. However, maintaining the CO2 concentration at 500–2,000 ppm during the harvest period increased the hardness of the mushrooms. Ventilation for 40 min at dawn every day during this period helped prevent the development of bacterial brown blotch by reducing water condensation inside the grower. The incidence of browning disease was reduced to 1% when the medium layer humidity index was decreased to approximately 10 at harvest time and the leaf sensor moisture index was maintained at 430–490.

A new Rehmannia glutinosa cultivar ‘Tokang’ was derived from ‘Jihwang 1’ seedlings by medicinal crop breeding team of National Institute of Horticulture and Herbal Science, RDA in 2009. It has pink flower, dark brown seed coat, light yellow root cortex. The plant type was some rising from the ground. The content of catalpol and extract were higher than the ‘Jihwang 1’(check variety). The content of catalpol was 4.55% and the extract was 71.2%. It showed stronger resistance to root rot compare with the ‘Jihwang 1’. The regional yield trials were conducted at three different locations from 2007 to 2009. The average yield of ‘Tokang’ was 21.1ton/ha, which was 12% more than the ‘Jihwang 1’. This cultivar is adaptable to the whole of Korea except for mountain areas. (Registration No. 4725)