Development of program for estimating optimum harvest date of medicinal plant Angelica acutiloba

To evaluate growth and develop a growth model of the medicinal plant Angelica acutiloba, we grew plants of one cultivar in one nursery at nine sites in Honshu and Shikoku, Japan, from 2016 to 2018. The collected data thus reflect differences in growing environment. The model estimates root dry weight and root head diameter from the number of days at the preferred growing temperature range between lower and upper limits based on the daily mean air temperature, and incorporates growth suppression by high temperatures in summer 2018. It was used to develop a program for estimating the optimum harvest date at any location in Honshu and Shikoku from Agro-Meteorological Grid Square Data of NARO.