Light interception and canopy sensing for tree fruit canopy management.

Abstract

This chapter provides a review of the principles, state-of-the-art technology and applications of light interception sensing systems and modelling for use in production agriculture. Case studies are presented where proximally sensed photosynthetically active radiation interception data measured using a mobile platform were used to assist in tree fruit canopy management and estimation of potential yield.

Estimation of Fractional Photosynthetically Active Radiation From a Canopy 3D Model; Case Study: Almond Yield Prediction

“…Furthermore, midday canopy light interception is often defined as the incoming Fractional PAR (fPAR, as a percent) intercepted by a canopy by measuring the PAR both below and above the canopy (McCree, 1966;Lampinen et al, 2012). It indicates actual intercepted PAR (or actual PPFD) that helps growers better understand their orchard productivity and spatial variability (Milne et al, 1992;Rojo et al, 2017).…”

“…A recent study has shown that an optimal orchard can potentially produce 58 lb acre −1 of dried kernel yield for every 1% of canopy fPAR interception, as measured by a mobile lightbar unit (Jin et al, 2020). Rojo et al (2017) also indicated that midday canopy fPAR could be used as a fundamental indicator for estimating the maximum potential yield for almond crop when there are no other stressors present. Although midday fPAR describes the potential yield, only a small portion (e.g., ∼10%) of the trees may reach maximum productivity (Jin et al, 2020).…”

“…However, for immature walnut orchards, fPAR increases throughout the season. Rojo et al (2017) found a second-degree polynomial curve for midday fPAR interception as a function of time to describe the canopy growth over the growing season in 2012 for almonds, suggesting the need for multiple measurements of canopy fPAR. For this purpose, the fPAR measurement tool should be readily available to use.…”