Horticulture lighting is the method for stimulating plant growth by artificial lighting fixtures when natural light is lacking.
Professional horticulture lighting is not only about providing adequate light for plant growth through the improvement of photosynthesis, but also about helping plants to produce a more attractive flower, better shape of leaves and more fruit as well as reduce or lengthen a particular growing phase.
For professional horticulture lighting, the proper customized recipes are essential for optimization of plant growing on purpose. The specific requirements of different plants in each growing phase and each part of plant organs determine which lighting recipe is better for optimize growth.
Apart from the variables consisting of temperature, humidity, water, oxygen, carbon and nutrients, unique characteristics of lighting also play a significant role in controlling plant growth. The light intensity, spectrum and duration impact plants' morphology, growth, fruiting as well as flowering.
Plants can convert light energy into chemical energy by photosynthesis. Plants need to absorb special light spectra emitting in order to generate necessary elements, such as chlorophyll, anthocyanin, carotenoid and phytochromes, within its 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 increase the growth speed and limit the electrical energy consumption at the same time.
Photosynthetically active radiation, also known as PAR, represents the spectral range of solar radiation from 400nm to 700nm. It defines the light the plant requires to support photosynthesis. In this range, plants' photosynthetic organisms have the ability to absorb light in the process of photosynthesis.
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.
Photosynthetic photon flux density (PPFD) is an additional measurement that offers the same information as PPF. It also stands for the photons in the spectral range of 400nm to 700nm. While the distinction between them is that PPF measures how many photons are given off from a light. On the other hand, PPFD refers to how many photons drop on a surface area in square meters.