LIGHT INTERCEPTION AND CANOPY CHARACTERISTICS AT LOW LATITUDES IN RELATION TO ORCHARD SYSTEM DESIGN
Increasingly pome fruits and stone fruits are being grown in the tropics and subtropics. The main environmental factors influencing the designs of orchard systems for deciduous fruits at low latitudes are:
- The total radiant energy available for growth in the tropics can be twice as great as that in the traditional north-European or north-American deciduous fruit growing areas. This is primarily due to increased length of season in terms of months with high energy availability and adequate temperatures.
- Light intensities are high but not radically different from those in traditional fruit growing areas such as Washington State: the total irradiance per month may be slightly less than in the months of highest irradiance in Mediterranean regions. Light penetration per unit depth of canopy (L.A.I.) is therefore likely similar.
- The high tropical solar altitudes mean that cast shadows from low angle sun are less important, that east-west rows are less efficient and that between row spacings should be closer.
- Delayed and poor foliation is still a common problem in the tropics due to inadequate winter chilling and break of vegetative buds. This aspect needs to be addressed by choice of suitable cultivars as well as use of dormancy breaking sprays, pruning, and training, to raise canopy densities to temperate-latitude levels.
Jackson, John E. (1997). LIGHT INTERCEPTION AND CANOPY CHARACTERISTICS AT LOW LATITUDES IN RELATION TO ORCHARD SYSTEM DESIGN. Acta Hortic. 451, 417-426
Malus pumila, temperature, tropics