Orchard systems for the 21^st century: perspectives, considerations and critique

How should orchard systems evolve to meet the multiple demands for sustainable fruit production in the 21^st century? Constraints in fractional light interception currently limit orchard productivity and fruit quality because orchard layouts cause discontinuous leaf canopies.
Yet extrapolated productivity-light interception responses show potential to markedly increase orchard productivity.
Our studies of new apple narrow-row, two-dimensional planting systems for this purpose, have defined a new leaf area index (LAI): light interception response that extends above 80% light interception at LAI of 3.5-5.2 and achieving yields exceeding 200 t ha^‑1 by their seventh year.
Overcoming the longstanding light utilization barrier to higher productivity and fruit quality, alone, is a too simplistic perspective for sustainable orchard systems in a future of resource constraints.
Yet the pomology and physiology enabling successful planar, narrow-row orchard designs provide a platform to examine orchard systems sustainability, which considers total resource requirements alongside of environmental footprints, natural capital and ecosystem services, guides adaptation of digital and automation technologies and redefines labor demands of operations.
The early experience in such considerations suggests innovation for greater sustainability depends on using simplified, narrow planar orchard canopies.
Increasing orchard systems’ biological potential (e.g., LAI: light interception relationship) also relies on planar canopies that reduce redundant leaf area and improve the light environment.
A context for analyzing orchard system sustainability is explored whereby the canopy standing dry mass represents the biological capital of the orchard system, and growth adds new capital.
Orchard management technologies have positive or negative effects on biological capital. ‘Productivity × fruit quality’ quantifies the investment return on capital, both monetary and biological.
We discuss how such analysis can guide innovation toward system sustainability using examples from orchard design and light relations; hypotheses on orchard water use; pruning, training, and growth responses; and addressing emerging digital technologies and automation

XII International Symposium on Integrating Canopy, Rootstock and Environmental Physiology in Orchard Systems

D.S. Tustin

planting systems, light relations, sustainability, resource use, dry mass conservation

https://doi.org/10.17660/ActaHortic.2022.1346.26