
PPFD to DLI Conversion for Leafy Greens
Are you planning a vertical garden or a small home-grow setup for leafy greens? If so, do you know how much light to provide fo optimal leafy green growth?
The optimum amount of light depends on two factors:
- PPFD (Photosynthetic Photon Flux Density) - the amount of photosynthetic light (400-700nm) photons that are cast over one square meter each second.
- DLI (Daily Light Integral) - the amount of photosynthetic light that that is cast onto the plants each day.
The inverse relationship between these two factors allows growers to use less light but for a longer time period, or more light for a shorter period. However, there may be biological limits to how much light the plants can absorb or how long the plants are exposed to light.
Use the chart below to determine the DLI (moles/m2/day) required for leafy greens based off of the PPFD (in umol/m2/sec). Shoot for the green shaded boxes. At a minimum, you can attain decent plant growth with an estimated DLI displayed in the grey shaded boxes.