EmergingPhase

The EmergingPhase represents a phenological sub-phase within a plant’s developmental timeline, responsible for simulating the transition from germination to emergence. It defines the conditions under which a seed emerges and completes the phase once those criteria are satisfied. Typically, it spans from the Germination stage to the Eergence stage, and its completion is determined by either environmental triggers, e.g. temperature, or a user-specified germination date.

Overview

The EmergingPhase models the transition from germination to emergence in the crop’s phenological development. Germination is assumed to occur when any of the following conditions are met:

  • Target thermal time for emergence is reached,
  • A specific emergence date is provided via the EmergenceDate property.

Emergence Triggers

Emergence occurs in one of two ways:

  1. User-defined emergence date

If EmergenceDate is specified, emergence occurs exactly on that date, regardless of soil moisture or temperature.

  1. Phase Target as GenericPhase

Events

Events Listened For

These are signals or notifications that the GerminatingPhase listens for from other parts of the simulation:

Event Purpose
Commencing Reset progress at the start of simulations
PlantSowing Set the phase target as GenericPhase. It also indicates the phase target cannot be dynamically modified.

Properties

Configurable and Reportable Properties

Property Type Description Required
Start string Phenological stage at which this phase begins (e.g. Sowing). Yes
End string Phenological stage that marks completion of the phase (e.g. Germinated). Yes
Target IFunction The target value for phase completion (e.g., required thermal time). Yes
Progression IFunction The daily progression towards the target (e.g., daily thermal time). Yes
EmergenceDate string Optional fixed calendar date to override environmental conditions. No
IsEmerged | bool | Boolean flag indicating whether the crop has emerged above the soil surface (i.e. this phase is happening above ground). | No |

Read-Only Reportable Properties

Property Type Description
FractionComplete double Fraction (0–1) indicating how much of the phase is complete. Always returns 0 as germination has occurred in next day of sowing.
ProgressionForTimeStep double The amount of progression made during the current time step (e.g. day).
ProgressThroughPhase double Accumulated units of progress through this phase between zero and target.

Usage

An EmergingPhase can be used to represent the emergence process of a plant, which is primarily influenced by sowing depth, shoot lag and shoot rate.

See Also