Plant Growth Lighting Requirements

The specific needs of plants determine which kind of lighting is most suitable for optimal growth, and artificial light must imitate the natural light that plants are most suitable for. If a plant does not get enough light, it will not grow, regardless of other conditions. For example: Vegetables grow best in full sunlight and thrive indoors. They need the same high light level, while leaf plants (such as philodendron) grow in the shade and can grow normally with lower light levels.

The way the plant light is used depends on the growth stage of the plant. Generally speaking, it is recommended that the plants receive 16 hours of irradiation during the seedling/growth stage, with an 8-hour rest time; during the vegetative stage, they receive irradiation for 18 hours with a 6-hour rest period; in the flowering stage, they receive a 12-hour and 12-hour rest period.

Photoperiod

In addition, many plants also require darkness and light cycles, and this effect is called the light cycle to trigger flowering. Therefore, the switch can turn the light on or off at the set time. The optimal photoperiod ratio depends on the type and type of plants, because some prefer long and short nights, while others prefer the opposite or medium day length.

When discussing plant development, the photoperiod is very important.

Plants that respond to photoperiod flowers may have facultative or specific responses. The part-time response means that a plant will eventually bloom, regardless of the photoperiod, the flower grows faster under a specific photoperiod. Professional response means that plants will only flower if they are grown under certain light conditions.

Photosynthetically active radiation (PAR)

Usually used to measure the brightness and lumens of light, but they are photometric units that measure the intensity of light perceived by the human eye.

The spectral level of light that can be used for photosynthesis is similar to, but not the same, as measured by lumens. Therefore, when measuring the amount of light for photosynthesis in plants, biologists usually measure the amount of photosynthetically active radiation (PAR) that the plant receives. PAR represents the spectral range of solar radiation from 400 to 700 nanometers, which generally corresponds to the spectral range that photosynthetic organisms can use in the process of photosynthesis.