XPalm - A growth and yield model for oil palm

XPalm is a growth and yield model for oil palm (Elaeis guineensis).

• XPalm - A growth and yield model for oil palm
• • Overview
  • Example outputs
  • Installation
  • Funding

Overview

XPalm is a process-based model for simulating oil palm (Elaeis guineensis) growth and development. The model simulates key physiological processes including:

• Phenology and development
• Carbon assimilation and allocation
• Water balance
• Reproductive organ development
• Yield components

Figure 1. Simplified diagram of the component models used in XPalm. The numbering is associated to the computational flow, from the first models to execute to the last.

XPalm implements a multiscale approach, modeling processes at different organizational levels:

Scene: Environment and canopy-level processes Plant: Whole palm processes Phytomer: Individual growth unit processes Organ: Leaf, internode and reproductive organ processes

The model uses a daily time step and requires standard meteorological inputs (temperature, radiation, rainfall...).

The model also includes a submodule VPalm to design palm tree mockups from a set of architectural parameters and allometric equations. It is designed to integrate smoothly with the physiological models from the package.

The model is implemented in the Julia programming language, which is a high-level, high-performance dynamic programming language for technical computing.

Example outputs

Here are some example outputs from the model, showing the evolution of variables at different scales:

Scene level:

Leaf area index (LAI) at the scene level over time:

Plant level:

Maintenance respiration (Rm), absorbed PPFD (aPPFD), biomass of bunches harvested, and leaf area at the plant level over time:

Leaf level:

Leaf area at the level of the individual leaf over time:

Soil level:

Fraction of transpirable soil water (FTSW) over time:

Installation

Install XPalm using Julia's package manager, typing ] in the Julia REPL (i.e. the console) to enter the Pkg REPL mode and then typing:

pkg> add XPalm

To use the package, type the following in the Julia REPL:

using XPalm

Funding

This work is supported by the PalmStudio research project, funded by the SMART Research Institute and CIRAD.