Horticulture lighting is the technique for stimulating plant growth by artificial lighting fixtures when natural light is lacking.
Professional horticulture lighting is not just about providing sufficient light for plant growth via the enhancement of photosynthesis, but also about helping plants to produce a more attractive flower, better shape of leaves and more fruit as well as shorten or lengthen a specific growing period.
For professional horticulture lighting, the correct customized recipes are essential for optimization of plant growing on purpose. The particular requirements of various plants in each growing period and each part of plant organs determine which lighting recipe is better for optimizing growth.
Apart from the variables including temperature, humidity, water, oxygen, carbon and nutrients, unique qualities of lighting also play an important part in controlling plant growth. The light intensity, spectrum and duration affect plants' morphology, growth, fruiting as well as flowering.
Plants can transform light energy into chemical energy by photosynthesis. Plants need to absorb special light spectra emitting in order to produce necessary elements, such as chlorophyll, anthocyanin, carotenoid and phytochromes, within it's organs for growing. A professional horticulture lighting recipe should optimize the spectrum of light source to fulfill the plants needs for photosynthesis in order to increase the growth speed and limit the electrical energy consumption simultaneously.
PAR: Photosynthetically Active Radiation
Photosynthetically active radiation, also referred to as PAR, stands for the spectral range of solar radiation from 400nm to 700nm. It defines the light the plant needs to sustain photosynthesis. In this range, plants' photosynthetic organisms have the ability to absorb light in the process of photosynthesis.
PPF: Photosynthetic Photon Flux
Photosynthetic photon flux (PPF) is a measurement that identifies the total amount of photosynthetic active radiation (PAR) a light produces. It values all photons from 400nm to 700nm based on the plant's photosynthetic response.
PPFD: Photosynthetic Photon Flux Density
Photosynthetic photon flux density (PPFD) is another measurement that offers the same information as PPF. It also represents the photons in the spectral range of 400nm to 700nm. While the distinction between them is that PPF measures how many photons get off from a light source. On the other hand, PPFD is about how many photons drop on a surface area in square meters.