Figure 1.
A comparison of radioactivity measured nondestructively by monitoring 14C accumulation in the leaf with a GM detector and by scintillation counting after destructive sampling of the leaf of salvia (A), gomphrena (B), alstroemeria (C), and maize (D). Measurements were made in leaf cuvettes as described in Methods. Each point is the measurement of one leaf under different environmental conditions. Values on the x axis were multiplied by 10−3 (i.e. a value of 5000 dpm is 5 × 106 dpm). CE is the value of radioactivity obtained by the GM detector divided by the radioactivity determined after destructive analysis of the leaf tissue multiplied by 100.