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Garden with Insight v1.0 Help: Plant daily development group

Plant is dead: If 'yes', this plant is completely dead, meaning no part of its biomass (dry weight) is considered to be alive. If 'no', at least some part of the plant is alive. Because plants are modular it is difficult to say exactly when a plant is dead.

Plant is in dormancy: This plant is perennial and has entered a dormant phase (where no new growth occurs) because this climate has a cold period. It will return from dormancy when the day length exceeds by a parameter the minimum day length for the year.

Plant life history stage: This plant's development stage. The stages are: seed (germination), vegetative period (heat unit index exceeds 0.2), floral induction (enough photothermal units accumulated), floral initiation (enough thermal units accumulated), reproduction.

Days seed has been germinating: The number of days this plant has been germinating and in the seed state.

Plant age in days: The age of this plant in days. Age affects a few life-history stage changes (such as the start of vernalization after six months), but for most events the heat unit index is used.

Plant age in years: The number of years this plant is old. Depends on the number of days old.

Cumulative heat units: Heat units (degrees C over the minimum temperature for this plant) accumulated since this plant 1) was planted, in which case heat units are being summed towards germination; or 2) germinated, in which case heat units are being summed towards maturity.
Heat unit index: The heat units (accumulated temperature over a minimum) accumulated for this plant divided by the heat units it is expected to accumulate in a normal growing season. Affected by minimum growth temperature and climate.

Heat unit factor for LAI and height: A factor based on the heat unit index and the S curve 'fraction of max LAI vs. heat unit index' used to calculate the leaf area index (LAI) and plant height over the growing season.

Yesterday's heat unit factor for LAI and height: Used to calculate the leaf area index (LAI) and plant height.
Leaf area index (LAI) today: The leaf area index (LAI) today. Leaf area index is the ratio of the total area of all the plant's leaves to the ground area covered by the leaves. LAI is important in determining the amount of new photosynthate (new biomass) made during photosynthesis.

Leaf area index at start of LAI decline: The leaf area index (LAI) at its peak, before it started to decline because of plant age (senescence). (If LAI has not yet declined, this will be the same number as the current LAI.) The timing and slope of the decline in LAI are determined by parameters.

Leaf loss index for leaves removed: A multiplier to the leaf area index (LAI) to account for individual leaves harvested (in the browser or using 'harvest parts'). Starts at 1.0 and is reduced by each leaf removed according to the biomass of that leaf in relation to the total plant biomass.
Floral induction accumulated photothermal units: Photothermal units accumulated so far for floral induction. On a day with the perfect photoperiod and temperature for floral induction, 1.0 units are accumulated. If the plant is not sensitive to photoperiod, only temperature is considered.
Floral initiation accumulated thermal units: Thermal units accumulated so far for floral initiation (the switch from vegetative to reproductive mode and the creation of reproductive meristems). On a day with the perfect temperature for floral initiation, 1.0 units are accumulated.
Vernalization accumulated thermal units: Thermal days accumulated towards vernalization (facilitation of flowering by cold temperatures). On a day in which mean air temperature equals the optimal vernalization temperature, one thermal day is accumulated.

Day planted, days from January 1: The day this plant was planted as a Julian day (a number of days since January 1st).

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Updated: May 4, 1998. Questions/comments on site to
Copyright © 1998 Paul D. Fernhout & Cynthia F. Kurtz.