What we need to know is that the growth rate of the plant depends on the light intensity, that is, the amount of light radiant energy absorbed by the plant surface, not depending on the number of light sources. Many people ask, what is the meaning of greenhouse interior lighting, how to do it, what kind of light source should I use?
The significance of interior lighting in a greenhouse is to extend enough light intensity in a day. It is mainly used to grow vegetables, roses and even chrysanthemum seedlings in late autumn and winter. Greenhouse lighting has a huge impact on growth and seedling quality. Usually, for tomatoes, the plant seedlings start to shine after two cotyledons grow, and continuous light for 12 days can reduce the seedling preparation period of 6-8 days. But more than 24 hours of light will be a plant growth disorder.
The most suitable lighting time is 8 hours a day. Artificial lighting is a must in the days of cloudy and low light intensity. The crop is given 8 hours of light per day at least at night, and the time of daylighting is fixed. However, the lack of nighttime rest time can also lead to plant growth disorders and reduced production.
For tomatoes, the most effective light time is from dusk to midnight, 16:00-24:00 or from midnight to early morning 24:00-8:00. So light for 8 hours and rest for 8 hours. In practice, we should provide illumination for plants throughout the growing season, from seedlings to colonization. In the final period we should reduce the light to 6 hours a day or even 2-3 days. If the time required for the planting period is long because of poor lighting conditions, the light usually lasts for one month.