Light is the energy needed for humans and other creatures to reproduce and carry out their activities.The energy for almost all life on earth comes directly or indirectly from the sun.Plants undergo a photosynthetic reaction,which converts the energy transferred by the sun into chemical energy and stores it in synthetic organisms.In addition to providing for their own needs,they also provide other heterotroph,providing the energy for the growth,development and reproduction of almost all living things on earth.In the visible light of solar radiation,the red and blue spectrum is an important energy source for plant photosynthesis.In the planting of facilities,red light is the first biological requirement,followed by blue light.Of course,other light also plays a key role in the growth and development of plants,which are in coordination with each other.Lighting conditions vary with location and time and are more specific in urban areas.The effects of light on plants allow them to adapt to different types of light over time.The southern part of China is a monsoon area,and the cold and warm current climate often meets here.The air mass from the Pacific Ocean contains a large amount of water and meets the cold air mass,which leads to the concentrated and lasting rainfall in the southern part of China,which has a bad effect on the growth of crops.In particular,there is not enough light,and plants are more susceptible to weather than more traditional open air plantings.Farmers often suffer heavy losses from bad weather.For this reason,LED supplementary light technology has been applied to solve the problem of poor growth of plants caused by climatic conditions and the need of different plants to supplement light.LED supplementary light is a new type of supplementary light source.Previous studies have shown that during the growth and development of plants,the main light absorbed is red light and blue light.LED supplementary light can freely regulate the ratio of red light and blue light and provide the most effective supplementary light for different plants.During plant growth,it helps to differentiate multiple branches and buds,accelerate root and leaf growth,improve the efficiency with which plants synthesize vitamins and carbohydrates,and reduce the time required for growth.The practical application of LED to the environment of plant installation shows that the LED plant lamp is especially suitable for the artificial light-controlled plant installation.This article selects a tomato and lettuce as experiment material,by studying the different combination of red and blue difference and red and blue LED light intensity on the influence of tomato seedlings,seedling’s height,root development,spacing,leaf area,chlorophyll content,photosynthetic rate and other factors as the evaluation standard,by studying the different growth stages to light irradiation,the lettuce in nutritional quality,chlorophyll content index as evaluation standard,to study the LED light the growth of tomato and lettuce.The results showed that the optimal light supplementation in the early stage of the growth of the two plants could promote the growth and development of the early stage of the seedlings,and the root structure,stem diameter,leaf area and chlorophyll content of the three parts of the rhizome and leaf were significantly better than the control group.At the same time,compared with traditional supplementary light,LED supplementary light group not only reduces energy consumption,but also is the optimal treatment.In the climate with more rain and less sun in south China,LED light source is the most common cultivation method.LED light source has an absolute advantage in the light source,and its energy consumption can save about 75%compared with the traditional light source.Under the traditional light source banana,LED light source has an obvious promoting effect on the physiological indicators of tomato seedlings.Under different combinations of red and blue,blue:red=1:1(BR11)and blue:red=3:2(BR32)are the best matches.Under different LED light intensity,from 200μmol·m-2·S-1to300μmol·m-2·S-1,the morphological and nutritional indexes of tomato seedlings were the best.In the research on lettuce,it is found that the illumination required by lettuce in different growth stages is not the same,and the reasonable collocation of light quality in different growth stages can promote the physiological indexes of lettuce to reach the optimal,and some indexes can even reach the saturation point.Thus,different plants need different light quality,light intensity is not the same.In this paper,tomato and lettuce are taken as examples to provide some theoretical support for the popularization of LED and scientific supplement light. |