Daily Light Integral (DLI)
DLI, or Daily Light Integral, is like a scorecard for how much sunlight a plant gets in a day. Think of plants as solar energy collectors, and DLI helps us measure how much sunlight they soak up every day. It's a bit like counting the number of sunny hours a plant enjoys.
Commercial growers use DLI to keep track of how much sunlight their plants are getting in a day. They measure it in a unit called moles of light per square meter per day, which tells them how much light the plant receives each day.
Calculating DLI indoors is usually simple because the light indoors is steady. But when you're growing plants outside or in a greenhouse, things get more complicated since the weather and the time of year can change how much sunlight plants get.
PPFD (Photosynthetic Photon Flux Density) from indoor lights stays the same so it's an easy calculation, but in the wild, sunlight is strongest around noon and changes throughout the day because of things like clouds and pollen.
Because many factors affect how long your plant is exposed to light, this DLI tool is really just helpful for calculating supplemental indoor light. It should be used as a rough guide.