Narrow mango canopies have more even light distribution and more efficient light use

Abstract

The intensity of light and the ability of leaves to e iciently use light are key determinants of the productivity of tree canopies. Temperate tree crops research has shown that the distribution of light within the canopy and the ability of leaves to adapt to light availability are a ected by genetics, pruning and canopy architecture. We tested the e ect of canopy width on light distribution within the canopy at two key phenological stages, and leaf functionality and morphology across a light intensity gradient. We then combined this understanding in virtual canopies to examine the e ect of canopy width on the net primary productivity per leaf area of wide and narrow Calypso® mango trees. We found the light extinction rate did not di er between narrow espalier training systems and wide conventional mango canopies, but the proportion of the tree’s leaf area in a high to moderate light intensity was greater with a narrow canopy. We also found that leaf morphology, productivity and stress tolerance are driven by light availability. When these e ects are modelled in digital canopies, narrow canopies have greater net primary productivity per leaf area than wide canopies at certain phenological stages. Our findings suggest that intensified mango orchards with narrow canopies benefit from more e icient use of light, but further research is needed to model this across an entire growth cycle.