This study is based on the investigation of Japanese ancient experienced agricultural techniques and historical and current exploration of strain and morphology of plants. We aim to dig up the tacit knowledge, which can guarantee the quality of production and profitability when they are applied for current medicinal plant cultivation. We focused on Paeonia lactiflora Pallas as the candidate of the farming products for the vitalization of mountainous area. Bon-ten (with white double-petaled flowers) is considered to produce highly qualified Paeoniae Radix in medical practice. We found several strains of the plant source different from Bon-ten as the origin of Yamato-Shakuyaku, bred after TOKUGAWA Yoshimune’s policy promoting the domestic cultivation of medicinal plants in Edo period. These strains include the cultivar with red single-petaled flower, which is drawn in ‘Matsuyama-Honzo’ by Morino Tosuke-Saikaku, who established private herb garden, ‘Morino herbal garden,’ supported by Tokugawa shogunate. Among Morino family documents, we also found the unpublished historical papers suggesting the various productions of crude drugs at Yamato region in Edo period, and considered the transition of domestic production area, cultivation strains and cultivation skills. We can find the descriptions of picking of buds and flowers among current production manuals, but it is suggested the possibility of flowers for ornamental or commercial use to improve economic efficiency by the investigation of regional cultures and interviews of experts of crude drugs.

The treatment by Kampo decoction is partly covered by National Health Insurance in Japan. However, this system is facing bankruptcy crisis because of rising prices of crude drugs in China, their main producer. The board of crude drug materials of the Japan Society for Oriental Medicine (JSOM) distributed questionnaires to 7416 JSOM member doctors, and performed statistical analysis (with JSOM approval) of 1877 answers to visualize the data. Twenty-six percent of respondents said that they had prescribed a decoction, and 29% of respondents said they had not, but wanted to prescribe a crude drug. Eighty-eight percent of doctors who prescribe decoctions offered medical treatment primarily to insured patients. Nine percent offered medical treatment at patients' own expense. The latter group prescribed decoctions more frequently. Many doctors were aware of the financial risk of prescribing crude drugs imposed by the drug price standard and rising crude drug import prices. Four hundred and fifty­-five doctors explained when they were most inclined to prescribe a decoction. Thirty-five percent of these said they used decoctions when they couldn't treat patients with extracts. This result implies a necessity for decoctions. Many doctors said they prescribed decoctions for autoimmune or allergic diseases. Financial constraints were the most frequently cited barrier to treatment with decoctions. This survey made clear the financial difficulties clinics are facing. We therefore calculated the amount of crude drugs used for decoctions to validate the possibility of their domestic production.

We focused on the traditional processing method which generates the superior quality of Yamato-shakuyaku. First, we assessed the historical literature written around Edo and Meiji period and rediscovered the traditional air drying method still inherited in Nara Prefecture. Then, we gathered and analyzed the data of medicinal plants production in Nara Prefecture among 1938 and 2019, and investigated the decline of local production and experienced agricultural techniques of peony through the transition of its yield. In order to visualize the ancient knowledge of crude drug manufacturers that contributes to the instruction of the skills for supply of seedlings, cultivation, and processing, we settled the meteorological observation devise at the outdoor drying shelf for 3 years, and recorded the real drying environment. When comparing the meteorological data with other cultivating area of peony using the estimated values of Agro-Meteorological Grid Square Data, the climate of Nara Prefecture was with high temperature and low humidity than other areas, and it seems to be quite suitable for air drying with adequate topography. The wind rose calculated by measured values of wind direction and wind speed showed the wind conditions in Nara that west wind was frequent in daytime and wind conditions are mildly but diversely changing. Among other producing areas of peony, the mechanical drying is major, whereas air-drying with low cost utilizing local environment features is still applied in Nara. We revealed the rationality of traditional methodology by digitization of meteorological factors which can be high added value.