Gas Exchange, Chlorophyll and Nitrogen Content of Mango Leaves as Influenced by Light Environment

Net CO 2 assimilation (A), stomatal conductance for CO 2 (g c ), water-use efficiency (WUE), specific leaf density (W a ), and leaf chlorophyll and nitrogen (N) content were determined for mango ( Mangifera indica L.) leaves that developed in full sun and 25%, 50%, and 75% shade. Leaves that developed in full sun had greater A and g c than leaves that grew in 75% shade. Leaf chlorophyll content and Ν content (dry-weight basis) increased as percent shading increased, but WUE and W a were not significantly affected by shading. Light response curves for A had a steeper initial slope for leaves that developed in full sun and 25% shade than for leaves that developed in 50% and 75% shade. The data indicate a greater quantum-use efficiency for leaves developed in high light levels than for those developed in shade.