The effects of low pH and macronutrient deficiencies on leaf biomass, concentration (g/100 g, w/w), and total yield (g/plant) of artemisinin, artemisinic acid, and dihydroartemisinic acid are discussed below. Because there are no pre-established levels of macronutrients deficiency for artemisia, plants were considered under nutrient stress after leaf symptoms were expressed (Figure 2).