Category: Grow Light, Grow Lights, Grow Lighting – Plasma 500w

Daily Light Integral – Purdue University

Daily Light Integral – Purdue University

Measuring Daily Light Integral in a Greenhouse
Ariana P. Torres and Roberto G. Lopez
Department of Horticulture and Landscape Architecture, Purdue University
excerpts – click to see original publication

Daily Light Integral
Daily light integral (DLI) is the amount of PAR received each day as a function of light intensity (instantaneous light: μmol·m-2·s-1) and duration (day). It is expressed as moles of light (mol) per square meter (m-2) per day (d-1), or: mol·m-2·d-1 (moles per day). The DLI concept is like a rain gauge. Just as a rain gauge collects the total rain in a particular location over a period of time, so DLI measures the total amount of PAR received in a day. Greenhouse growers can use light meters to measure the number of light photons that accumulate in a square meter over a 24-hour period. Jim Faust and colleagues at Clemson University have developed maps of monthly outdoor DLI throughout the United States (Figure 1). These maps illustrate how latitude, time of year, length of day (photoperiod), and cloud cover influence DLI and vary from 5 to 60 mol∙m-2∙d-1. In a greenhouse, values seldom exceed 25 mol∙m-2∙d-1 because of greenhouse glazing materials and superstructure, the season (which affects the sun’s angle), cloud cover, day length (photoperiod), shading, and other greenhouse obstructions, such as hanging baskets.

Supplemental Lighting
Under light-limiting conditions (such as during the winter in temperate climates), most greenhouse crops benefit from supplemental lighting. But remember, supplemental lighting is generally worthwhile only when increased photosynthesis leads to greater revenue (such as more turns of plugs, cutting liners or more cut flowers).

Daily Light Integral - Purdue University

Daily Light Integral – Purdue University
excerpts – click to see original publication

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Chameleon Plasma Grow Lighting my be able to help Growers in northern climates extend their growing season by providing supplemental DLI. The chart below DLI expectation for 100′ sq. ft. coverage. Add the value below to the average DLI from you region to see if your plant material would benefit.

 

Daily Light Integral - Purdue University

Average PPFD – 60.50 µmoles/m2/s
Average DLI – 5.23 mols
Recommended Distance for Low Light-Level Crops
in Greenhouse Supplemental-Lighting Applications

Author: ChameleonGrowSystems.com
Updated: 05/18/2016
Product ID: 00001453
MSRP $1395 USD In Stock