Daily Light Integral Formula

Dli is an important variable to consider particularly when growing plants in a greenhouse.

Daily light integral formula.

Light particles particularly those that have a wavelength between 400 and 700 nm provide plants with the energy for photosynthesis. Daily light integral or dli are the total amount of photons in the par 400 700 nm range that land on a target point over the course of a day meeting proper dli requirements has a big impact on a plant s root and flower development. This metric is important to measure since the amount of light your plants get in a day. It is expressed in terms of moles of light per square meter per day or mol m 2 d 1.

It is a function of photosynthetic light intensity and duration day length and is usually expressed as moles of light mol photons per square meter m 2 per day d 1 or. An area s daily light integral is the number of light particles that are received in one full day. Similarly the daily light integrals change from 42 to 33 to 25 to 16 in august september october and november respectively. Different types of plants require different dli levels and have different photoperiods so check out some excellent research on the subject done by the purdue.

Full credit and many thanks to both of these scientists daily light integral dli describes the number of photosynthetically active photons individual particles of light in the 400 700 nm range that are delivered to a specific area 1m2 over a 24 hour period the formula for calculating dli is. Daily light integral dli is a measure of the aggregate amount of par light that a surface receives over the course of a day. It is expressed as moles of light mol per square meter per day. The daily light integral dli is the number of photosynthetically active photons photons in the par range accumulated in a square meter over the course of a day.

A light emitting ppfd 1000 running 12 hours emits a dli 43 2 moles day computed as 60 sec min 60 min hr 12 hrs day ppfd 1 million current research indicates cannabis grows best at ppfd 1500 dli 65 and temperature 30 degrees c lighting. Ho 238 w measuring daily light integral in a greenhouse purdue extension 2 daily light integral daily light integral dli is the amount of par received each day as a function of light intensity instantaneous light. For example the outdoor daily light integrals for columbia missouri are 28 moles day in march 37 moles day in april and 42 moles day in may. Daily light integral referred to as dli is the amount of photosynthetically active radiation par received each day as a function of light intensity and duration.

The daily light integral changes rapidly during the spring and fall. Dli can also be defined as the amount of photosynthetic active radiation par received each day. Definition of daily light integral dli daily light integral is a measure of the amount of light received in a particular area over a 24 hour period. μmol m 2 s 1 and duration day.

Mol m 2 d 1. Daily light integral dli dli ppfd over the course of a light cycle measured as moles of par photons per day example.