EFFECTS OF LIGHT AVAILABILITY ON THE ARCHITECTURE OF CANOPY IN MANGO (MANGIFERA INDICA L.) CV. MANZANA TREES.

Dimensions of leaf area, leaf dry weight per area and leaf density were measured in seven 13 yr. old mango (Mangifera indica L.) CV. Manzana trees in relation to the light environment in the canopy throughout a growing cycle. Three trees were deflowered and defruited to relate light and fruit influence on canopy architecture. The amount of penetrating PAR as measured with a Ceptometer sunfleck decreased drastically inside the canopy affecting proportionally the LAI (leaf area index). Lack of fruit caused an increase in LAI during the parallel transition period from flowering to fruiting in defruited trees. Relative leaf growth index (RLGI) in fruited trees showed an higher increase in leaf area/unit area than the leaf weight/unit area during the period from vegetative stage to flowering and a higher increase in leaf weight/unit weight than the leaf area per unit area during fruit growth period which was interpreted as evidence that plant resources are mainly invested in fruit growth during this period. The study suggest that if tree if managed to facilitate light penetration in the canopy, the photosynthetic activity during fruit growth period might be augmented to increase yield.