When designing the ideal lighting environment for indoor plant growing, indoor growers should consider three characteristics: light quality, light quantity, and light duration.
Once you understand how these features work together, you can optimize your indoor planting lighting environment to grow healthy, even crops and benefit from year-round production, increased yields and shorter harvest cycles.
Spectrum
Light quality is the wavelength of light reaching the crop. The light used for indoor plant cultivation mainly comes from the photosynthetically active radiation (PAR) band of the spectrum. PAR has a wavelength between 400 and 700 nanometers (nm). These wavelengths drive photosynthesis, the chemical process that drives plant growth. LED technology allows you to provide plants with the most useful wavelengths of light.
While we are currently focusing on wavelengths in the PAR (400-700 nm) of photosynthesis, emerging evidence suggests that wavelengths outside this band can facilitate photosynthesis. As LED research continues to develop, we may see changes in the boundaries of PAR regions in the future.
Total effective optical radiation
The amount of light is the total amount of light received by the crop. Indoor plant cultivation usually uses the PPFD value to measure the amount of light. PPFD is the amount of micromoles of light hitting your crop per second in any given square meter.
Every crop has an ideal PPFD and it requires optimal growth. This light requirement reflects the plant’s natural habitat. For example, plants grown on the forest floor, such as orchids, have lower PPFD needs than tomatoes grown in open valleys.
The ideal lighting environment achieves the target PPFD of the crop without exceeding the target and distributes light evenly throughout the plant canopy. This ensures that your crops grow equally evenly.
Excessive light on crops can damage plants and waste energy. For example, too much light on lettuce can cause burnt leaf tips, which makes the damaged plant more difficult to sell.
Light time
Light duration is the number of hours of light your crop receives. Light duration is also known as photoperiod. Photoperiod controls flowering, dormancy and other biological responses in many plants.
