What lights are used in plants?

Background introduction

In recent years, plant factories have received unprecedented attention. According to the United Nations, the global population will reach 9.5 billion by 2050, and human food demand will increase by 70%-100% compared with the present, while the per capita arable land area has dropped from 0.33hm2 to 0.22hm2 in the last 30 years, a drop of 31.7%.

Among the many environmental factors that affect plant growth, light is one of the most important factors. The so-called "everything grows by the sun", the requirements of plants for light are mainly the color of light, spectrum, light intensity and illumination time. Therefore, by artificially developing the illumination of a specific spectral illumination product, plant growth can be greatly improved.

It is understood that the electricity cost in the production cost of plant factories accounts for about 30%. If there is no cheap power supply and high efficiency artificial lighting to reduce production costs, plant factories are not very attractive to farmers. Therefore, the development of resource-saving light sources is a necessary need to build plant factories.

In addition, in recent years, with the improvement of agricultural productivity, greenhouse greenhouses have developed rapidly. Traditional greenhouse greenhouses generally use common electric light sources to supplement lighting and apply different covering materials and other agricultural technical measures. These measures have different degrees of problems: lack of specific spectrum The analysis of the components leads to impure optical quality treatment, inconsistent light intensity, lower than the plant light compensation point, and low energy efficiency of the illumination source. Plant cultivation lamps developed by developed countries such as Japan, the United States, and the Netherlands are mainly LED light sources, but the upstream technology and core patents of LED lighting products are monopolized by large foreign companies, resulting in high cost of LED plant lighting products on the market. , technology monopoly, manual operation switches, difficult to promote and popularize.

Test development and process

Sunlight is composed of many different wavelengths of light, and only a very small part of the solar radiation spectrum affects photosynthesis, accounting for about 5% of the proportion of sunlight. As early as 2006, Hongyuan began to study the special spectrum of plant lights. Through research, we obtained the best ratio of red light of 620-680nm and blue-violet light of 400-500nm, thus successfully developing the Promise plant lamp.

The Hongyuan Intelligent Plant Factory is an efficient agricultural system that achieves continuous crop production through high-precision environmental control in the facility. As shown in Figure 1 and Figure 2, it is based on the B/S architecture and remote control via WIFI. Environmental factors such as temperature, humidity, light, and carbon dioxide concentration during crop growth are automatically controlled and are not subject to external conditions.

The following are some of the study parameters:

(1) Lettuce: The light source of colonization and seedlings is best suited for growth using red and blue light 6:1 and 7:1 light sources, respectively.

(2) Amaranth: The ratio of plant height, stem diameter and leaf width of amaranth under red/blue 7:1 treatment was significantly higher than other treatments.

(3) Cucumber: 7:2 is the best red-blue ratio for the growth of cucumber seedlings. The 7:1 growth period is the best red and blue light ratio.

(4) Green vegetables, water spinach: 7:1 is the best red and blue light ratio for the growth of green vegetables and water spinach leaves.

(5) White radish: the most suitable light quality for growth: red and blue light ratio of 8:1.

(6) Oil wheat: The ratio of red and blue light is 9:1, which is conducive to the growth of oil wheat.

(7) Strawberries and tomatoes: Red and blue light 9:1 is most beneficial for the growth of strawberries and tomatoes, and the fruit is full and nutritious.

(8) Holly: Red and blue light are arranged in a ratio of 8:1. The holly grows best, is strong and has a very developed root system.

(9) Sprouts: The most obvious effect is the ratio of red, green and blue light of 6:2:1.

(10) Calla Lily: The growth rate is best with a ratio of red and blue light of 6:2.

(11) Anthurium Sun: Comprehensive analysis, red blue light 7:3 treatment is better, is conducive to morphology, root growth and dry matter accumulation.

(12) Dendrobium candidum: red blue light 7:3, its proliferation effect is best; 6:4, it is more conducive to photosynthesis and material accumulation of seedlings.

In our laboratory, lettuce was planted on July 8, 2014 by seedlings. Planting environment:

● Illumination above the plant: 2600-2900lx (purity red and blue spectral illuminance value, non-white illuminance value), no natural illumination, complete artificial lighting system, pre-illumination cycle 6 h on, 2 h off, 3 cycles per day; late 14 h On, 10 h off, cycle 2 times a day;

● Ambient temperature: 28-30 ° C (post-air conditioning starts to add, maintain 28 ° C)

● Relative humidity: 50%-70% (the air conditioner is turned on to about 60%)

After about three weeks, the single lettuce grew from the first four leaf petals to eleven, with a width of 9 to 10 cm. The growth height is relatively good, with a height increase of about 80%. Lettuce basically has a good stem development, and the height rises rapidly, as shown in Figure 3. The growth rate is compared with the lettuce group grown under the conventional daylighting environment of our company, which accelerates plant growth by more than 50% (based on the leaf area and weight).

Figure 3 Laboratory lettuce planting test samples

In addition, the plant lighting products sold by our company have been tested in foreign countries as shown in Figure 4. The growth of plants under the illumination of the Promise plant lamp:

Figure 4 relevant foreign test report

According to the research report of the Institute of Bio and Biophysics of the National University of Tomsk, Russia, and the practice of the Hongyuan Laboratory, the Hongyuan Promise plant lamp nearly doubles the plant growth compared to the sodium lamp plant lamp (based on the leaf area and fruit weight). Out). The report is based on comparative test data of 200 W and 400 W high pressure sodium lamps for LVD Promise Plant Lights, which was tested at the National University of Tomsk, Russia for nearly half a year, by planting samples of tomatoes such as tomatoes.

Figure 5 wifi intelligent control interface

The artificial environment cloud service system, as shown in Figure 5, is the most advanced agricultural IoT system. The system is based on the most advanced WIFI wireless communication technology, and feedbacks monitoring information of various Sensor devices (such as humidity sensor, temperature sensor, soil K+ ion sensor, etc.) to the software, and intelligently analyzes the needs of plant factories. Supplementary raw materials or environmental replenishment actions, such as warming the floor to open the floor heating equipment; if the soil is too dry, open the drip pipe equipment; if the CO2 concentration is lowered, the air circulation will be automatic. At the same time, the entire environment has a video monitoring function, which can feedback the actual situation in the factory to the central software in real time, so that the user can remotely analyze and control. The whole system is based on the B/S architecture, and can push real-time monitoring information, early warning information, agricultural technology knowledge, etc. to the farmers through information terminals such as mobile phones, PDAs, computers, etc., to achieve greenhouse intensive and networked remote management, and fully utilize the Internet of Things technology facilities. The role in agricultural production. This system is suitable for all types of solar greenhouses, multi-span greenhouses, smart greenhouses.

in conclusion

This project is based on WIFI's Promise Plant Light Cultivation Intelligent Filling System. It adopts LVD induction lamp as the fill light source, combined with remote intelligent control system, which can meet the needs of plant wavelength illumination. It is especially suitable for light-controlled plant facility cultivation environment. To meet market demand. The principle of “fool camera” is realized in the central software interface, that is, any family member can effectively participate in and implement the cultivation of agricultural crops, which is closer to the psychological and physiological needs of modern consumers. The project itself must be planted to meet the national standards for pollution-free certification.

The implementation of this project can improve the situation of farmers relying on the weather to help farmers improve production conditions, improve the quality and yield of plants, and fruit crops can shorten the result period, increase income, and produce significant economic and social benefits.

The project can be widely used in plant cultivation, greenhouse light supplementation, plant tissue culture, plant factories, and has many advantages such as promoting plant growth, regulating plant morphology, energy conservation and environmental protection, and not only emitting monochromatic light with narrow light waves, such as red. , orange, yellow, green, blue, infrared, etc., and can be arbitrarily combined according to different needs of plants, and it is also a cold light source with low heat characteristics, which can irradiate plants at close range and improve space utilization, which can not only provide for the growth of agricultural plants. Reasonable light environmental conditions, reducing the use of pesticides, hormones and other chemicals to ensure food safety, but also a low-energy green light source, has broad application prospects, is an important development trend of plant lighting sources in the future.