SEASONAL ACCUMULATION OF ARTEMISININ IN ARTEMISIA ANNUA L.
Changes in artemisinin accumulation and biomass formation through plant development of 4 breeding lines of Artemisia annua L. was examined under field conditions. Initially all leaves and then all leaves and flowers were collected from the plants every 2 weeks from Jul 10 to Oct. 16. The 4 lines reached maximum artemisinin accumulations at harvest 6, on Sep. 18, when the daylength was 12 hours, and maximum biomass yields at harvest 6, 7 and 8, on Sep. 18, Oct. 2 and Oct. 16. Maximum artemisinin accumulation coincided with full flowering for lines 2–5, 7–9 and 20–2, and at the initial floral bud stage for line 18–7. Maximum artemisinin concentration appears more closely associated with the specific photoperiod than with a specific stage of plant development.
Morales, Mario R., Charles, Denys J. and Simon, James E. (1993). SEASONAL ACCUMULATION OF ARTEMISININ IN ARTEMISIA ANNUA L.. Acta Hortic. 344, 416-420