Maximising light interception and productivity of Australian apple orchards

February 2007 | Dr Simon Middleton, Queensland DPI&F | Future Orchards® notes

This technical paper explains why orchard light interception and light distribution are central to both high yield and fruit quality. Dr Simon Middleton notes that intercepted sunlight supplies the energy for photosynthesis and therefore for canopy growth, fruit growth, colour development and crop production.

The paper recommends designing and managing orchards to intercept about 60 per cent of daily sunlight at mid-season while still allowing adequate light through the canopy. It warns that moving much beyond this level can increase shading, with negative effects on yield, fruit size, colour and soluble solids.

The two core design principles are to maximise light interception for yield and maintain good internal light distribution for marketable packout. The notes identify dwarfing rootstocks and high-density plantings, generally above about 1,900 trees/ha, as a practical way to build productive canopy quickly and recover establishment costs earlier.