The Effect of Light on the Translocation from Sugar-beet Leaves

Illumination was found to increase the rate of translocation from sugar-beet leaves. This stimulation of translocation was not dependent on the concentration of either sugar or ATP in the leaf. It was, however, dependent on carbon fixation by the leaf and it increased with light intensity in a manner similar to that of assimilation rate. It was evident that these parallel stimulations by light might have a common cause, concerning the nature of which some suggestions are made. It was also shown that under normal daylight conditions other factors affected translocation rate and that by suitable experiments their effects on translocation could be determined and shown to act independently.