Today, Yuepu Optoelectronics shares how to determine the light spectrum required for different plant growth stages?

To determine the light spectra required for different plant growth stages, it is necessary to consider the photosynthetic characteristics of plants, photomorphogenesis reactions, and the demand features of different growth stages. The following is a specific analysis:

Understanding the characteristics of plant photosynthesis: Plants mainly rely on photosynthetic pigments such as chlorophyll to absorb light energy for photosynthesis. Among them, chlorophyll a and chlorophyll b mainly absorb red and blue light, while carotenoids mainly absorb blue-violet light. Therefore, red light and blue light are crucial for plant photosynthesis and are the basic spectral components required for plant growth.

Studying the photomorphogenesis response in plants: Light not only provides energy for photosynthesis in plants but also serves as an environmental signal to regulate their growth and development, which is known as photomorphogenesis. Light of different wavelengths plays different roles in optical morphogenesis. For example, red light can promote the elongation of plant stems, the expansion of leaves and the synthesis of chlorophyll; Blue light plays an important role in the phototropism of plants, stomatal opening, chloroplast development and inhibition of stem elongation. Far-red light is involved in regulating processes such as the flowering time and seed germination of plants.

The spectral seed germination period should be determined based on the requirements of different growth stages: At this stage, sufficient water, suitable temperature and certain light are mainly needed to break the seed dormancy and promote the growth of the embryo root and embryo bud. Generally speaking, the ratio of red light to far-red light has a significant impact on seed germination. An appropriate ratio of red light to far-red light is conducive to promoting seed germination. For example, the germination rate of lettuce seeds is relatively high under red light irradiation.

Seedling stage: During the seedling stage, plants need to quickly establish a photosynthetic system to promote the growth of their root systems and leaves. At this time, blue light is conducive to the development of the root system of seedlings and the thickening of leaves, enhancing the stress resistance of plants. Red light can promote the expansion of leaves and the synthesis of chlorophyll, thereby enhancing the efficiency of photosynthesis. Therefore, providing a spectrum rich in blue and red light during the seedling stage, such as a spectral combination with a red to blue light ratio of 2:1 to 4:1, is usually beneficial for the vigorous growth of seedlings.

Vegetative growth period: During the vegetative growth period, plants require a large amount of light energy to carry out photosynthesis, accumulate photosynthetic products, and promote the growth of vegetative organs such as stems and leaves. At this stage, red light and blue light remain the main spectral demands, but the proportion of green light can be appropriately increased. Although green light is absorbed less in photosynthesis, an appropriate amount of it can enhance the absorption and utilization efficiency of light by plants, making them grow more vigorously. Generally, the light quality ratio of red, blue and green can be adjusted to about 5:3:1.

Flowering and fruiting period: When entering the flowering and fruiting period, the growth focus of plants shifts from vegetative growth to reproductive growth. At this time, red light plays a crucial role in promoting flower bud differentiation, flowering and fruit development of plants. Appropriately increasing the proportion of red light and reducing the proportion of blue light can help improve the flowering rate and fruit setting rate of plants. For instance, for vegetable crops such as tomatoes, adjusting the ratio of red to blue light to 6:1 to 8:1 during the flowering and fruiting period can significantly promote the growth and development of the fruits. Meanwhile, some plants also have a certain demand for far-red light during the flowering and fruiting period. Far-red light can participate in regulating the flowering time and the development of flower organs of plants.

In addition, different plant species have varying requirements for light spectra. When determining the light spectrum, it is also necessary to refer to relevant scientific research literature and practical experience, and optimize and adjust it for specific plant species. Meanwhile, factors such as light intensity and duration also interact with the light spectrum, jointly influencing the growth and development of plants. In practical applications, these factors need to be comprehensively considered to achieve the best planting effect.

Yuepu Optoelectronic Technology was established in 2024 and is a subsidiary of Guangzhou Jinyi Electrical Appliance Co., Ltd. and the Guangdong sales headquarters of Jiangsu Houmulai Lighting Technology Co., LTD. It is a solution provider integrating R&D, production and sales of LED light sources, lighting fixtures, smart products, Internet of Things smart software and other series of products, as well as offering comprehensive lighting solutions.

The company is based in China and looks to the world. It adheres to the five major principles of health, safety, aesthetics, economy and technology, and segments the characteristics and demands of domestic and foreign markets to be a source of love and green light.