home news forum careers events suppliers solutions markets expos directories catalogs resources advertise contacts
 
News Page

The news
and
beyond the news
Index of news sources
All Africa Asia/Pacific Europe Latin America Middle East North America
  Topics
  Species
Archives
News archive 1997-2008
 

LumiGrow releases Horticultural Lighting Definitions Guide


Emeryville, California, USA
August 7, 2019

It can be challenging to know which horticultural lighting terms and measurements to focus on when researching commercial grow light options. Continuing from our previous post on Lumens, Lux and PAR, let’s dive deeper into the light measurements important for plant growth so that you can make the best lighting choice for your production.

Photosynthetically Active Radiation (PAR)

PAR is the waveband of the light spectrum that plants use for photosynthesis. PAR is not a measurement of light, but rather represents the waveband in the light spectrum which is used by plants for photosynthesis. That’s why we say, “PAR is for plants”.

Lumens are a measurement of the amount of light that’s visible to the human eye. Lux is the measurement of the intensity of lumens (exe. 1 lux equals 1 lumen per square meter). These measurements shouldn’t be used in horticultural applications since they don’t measure the light that plants use for photosynthesis. That’s why we say, “Lumens are for humans”.

PAR v Lumens graph
Plants perceive light as photosynthetically active radiation (PAR). Humans perceive light as lumens.

 

Photosynthetic Photon Flux (PPF)

PPF is the amount of PAR a light source produces. PPF is measured in microles per second or μmol·s-1. This is an important measurement to look for when comparing horticultural light fixtures. PPF tells you how much light your fixture will produce that your plants can use for photosynthesis.

Photosynthetic Photon Flux Density (PPFD)

PPFD is the amount (also referred to as intensity) of PAR light that lands on a square meter each second. PPFD is measured in micromoles per square meter per second (μmol·m-2·s-1). In other words, PPFD is how much PPF is hitting each square meter of your crop at any given second. It is important to look at PPFD when planning your grow light installation. Adjusting your fixtures’ height and density will affect the PPFD at your crop canopy.


PPFD graphicPPFD is the amount of PAR photons that land on a square meter per second.

 

Daily Light Integral (DLI)

DLI is the amount of PAR that lands on a square meter surface over a 24-hour period. DLI is measured in moles of light per square meter per day (mol·m-2·d-1). You can think of this as the accumulation of PPFD over a full day. In human terms, you can think of DLI as a plant’s daily caloric intake of light.

Learn more about DLI in our article on Understanding Light Using Daily Light Integral.

Photosynthetic Photon Efficacy (PPE)

PPE measures a light fixture’s efficiency for converting electrical energy into PAR light. This is expressed as micromoles per Joule (μmol·J-1). PPE is an important measure for comparing the efficiency of different manufacturers’ fixtures.

To access the rest of the article and LumiGrow's Horticultural Lighting Terms Cheat Sheet, go to www.lumigrow.com/horticultural-lighting-terms-guide.

 

About LumiGrow

LumiGrow revolutionized horticulture in 2008 with the introduction of the first smart LED grow lights in North America. Today, LumiGrow leads the world forward in grow light innovation with their TopLight and BarLight smart fixtures designed to maximize a growers’ profits. The LumiGrow lights are wirelessly controlled by their smartPAR software to optimize yield, quality, and custom plant traits. LumiGrow lights can be fine-tuned for greenhouse environments by pairing with their award-winning smartPAR Light Sensor to ensure consistent crop production year-round at the lowest energy cost.

LumiGrow has the largest install-base of smart LED grow lights in North America with installations worldwide. For more information about LumiGrow, please see www.lumigrow.com.



More news from: LumiGrow, Inc.


Website: http://www.lumigrow.com

Published: August 8, 2019

The news item on this page is copyright by the organization where it originated
Fair use notice

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

  Archive of the news section

 

 


Copyright @ 1992-2024 SeedQuest - All rights reserved