Figure 2.

Net CO₂ (A) and O₂ (B) exchanges in the 24- to 25-d-old white lupin plant described in Figure 1. Shoot-day values are shown as photosynthetic CO₂ uptake (A) or O₂ production (B). Respiratory CO₂ loss (A) or O₂ uptake (B) for root-night, root-day, and shoot-night are presented in stacked bar graphs so that the difference between the sum of respiration and the photosynthetic values will illustrate the net carbon gain or the net O₂ production of the plant over the 24-h period. Values are means of three diurnal measurements obtained sequentially using a single plant.