Acta Horticulturae; Proc. IS on Appl. of Precision Agric. for Fruits and Vegetables vol:824 pages:37-48
IS on Appl. of Precision Agric. for Fruits and Vegetables location:Orlando, Fl, USA date:01-2008
Recent advances in remote sensing platforms and the increasing accessibility of
time series have proven their potential use in agronomic production processes.
Relating detected trends to physiological processes, however, poses issues caused by
the interaction of reinforcing or antagonistic non-linear trends. A bottom-up modeling
approach is used to gain insights in the potential of remote sensing to monitor citrus
production processes. Physiologically related morphological and spectral responses of
Valencia citrus trees are simulated in a realistic virtual orchard with explicit canopy
geometry. The modeling of plausible tree geometries, orchard layout and leaf, stem,
and soil spectra (400-2500 nm) are outlined. A reference orchard was set up and
calibrated using measurements of spectra and canopy structure and orchard layout.
Physiological changes are simulated in scenarios and compared to a reference
situation. These include the effects of citrus and weed leaf chlorosis, changes in leaf
area, bending of leaves, leaf curl, and crop load. Additional simulations analyze the
effects of different illuminations and compare physiologically induced changes to the
natural variability in orchards.