Published online by Cambridge University Press: 03 October 2008
Leaves of Coffea arabica L. were sampled from an artificial shade trial to examine the effects of two levels of shade, compared with full exposure, on size, structure and chlorophyll content. A grid was designed for the rapid measurement of leaf areas in the field, and individual leaf areas were found to increase progressively with shading. Since dry weight per leaf was not affected, an increase in specific leaf area was entailed. Leaf size varied greatly with season of formation, a wider range occurring in selection N39 than KP162, but the reasons for the variation were not clear. Neither lamina thickness nor proportion of palisade tissue varied with shade treatment. Chlorophyll per unit weight increased with shade in KP162 but with N39 was only greater under dense shade. Chlorophyll per unit area did not alter with shade, but N39 had significantly more chlorophyll than KP162 on both a weight and an area basis.