Horticulture lighting is the method 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 through the enhancement of photosynthesis, but also about helping plants to produce a more beautiful flower, better shape of leaves and more fruit as well as reduce or extend a particular growing period.
For professional horticulture lighting, the correct customized recipes are essential for optimization of plant growing on purpose. The specific requirements of different plants in each growing stage and each part of plant organs determine which lighting recipe is better for optimizing growth.
Growth
Aside from the variables consisting of temperature, humidity, water, oxygen, carbon and nutrients, special qualities of lighting also play an important role in controlling plant growth. The light intensity, spectrum and duration influence plants' morphology, growth, fruiting as well as flowering.
Photosynthesis
Plants can transform light energy into chemical energy by photosynthesis. Plants need to consume special light spectra emitting in order to generate 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 satisfy the plants needs for photosynthesis in order to maximize the growth speed and reduce the electrical energy consumption at the same time.
PAR: Photosynthetically Active Radiation
Photosynthetically active radiation, also called PAR, represents the spectral range of solar radiation from 400nm to 700nm. It specifies the light the plant requires to sustain photosynthesis. In this range, plants' photosynthetic organisms are able 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 releases. 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 provides 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 the amount of photons emitted from a light. On the other hand, PPFD is about how many photons fall on a surface area in square meters.
