Diurnal Changes in Photosynthetic Capacity of Barley Leaves

Abstract

Measurements of oxygen uptake and loss in dark and light were made on slices of barley leaves cut at different times during the day. Oxygen consumption in the dark was the same at all times, but there was a decrease in oxygen production in the light at about midday. It is suggested this reduction was due to a change in intrinsic photosynthetic capacity of the leaf.