The Effect Of Light-Emitting Diodes On Growth Of Peanut And Cucumber Seedlings

Light-emitting Diode (LEDs) is a new type of energy-saving light source. It has been used in facility cultivation. LED light has the advantages of small size, low power, low heat and high brightness. The R plus B LED light is consistent with the special range of the growth of plants which can be utilized for the growth of plants. Traditional light sources are fluorescent lamps, high pressure sodium, and dysprosium lamps. These light sources have the disadvantages such as high energy consumption, low photoelectric conversion rate, and they are hot light sources. Traditional light sources have high power consumption in the total energy consumption. The research of different LED light on the growth of peanut has not been reported. In the present research, we studied the growth and development of peanut (Arachis hypogaea) under fluorescent lamps and LED light source, the effects of different light sources in the growth of peanut, and the effects of different light sources on growth of cucumber (Cucumis sativus L.) seedlings on the greenhouse. We found the best light qualities for the growth of peanut and cucumber, and to provide theoretical and experimental evidences in facility cultivation.1. We studied the progress of growth and development of peanut under fluorescent lamps. We found that peanut was able to finish its whole growth progress. Flowering and pod periods were also normal. But its height was short, and its stem was thin. All the growth progress took150days while it was127days under natural light. The growth cycle was longer under fluorescent lamps and the yields were low. The average number of peanut pod was2.2under fluorescent lamps, while it was8.2under sunlight. The average weight of the pod was3.98g under fluorescent lamps, while it was4.58g under sunlight. The average dry weight of the pod was2.01g under fluorescent lamps, while it was2.72g under sunlight. The results showed that peanut can be grown under fluorescent lamps. The light intensity of fluorescent lamps was low, which had a negative impact on the growth of peanut. Our study showed that by controlling the light sources, we were able to control the growth and development progress of peanut.2. We studied the effects of light-emitting diodes on the growth of peanut. The results showed that R:B=7:3LEDs was conducive to the growth of peanut seedlings. The fresh weight, dry weight, plant height, root length and content of chlorophyll were greatest under R:B=7:3LEDs. In flowering period of the R:B=1:1LEDs was better for the synthesis and accumulation of chlorophyll. The contents of sucrose, starch and soluble sugar were also increased. Consumption of chlorophyll and soluble sugar was greatest under R:B=1:1LEDs in the flowering period. R:B=3:7LEDs was better for the growth and yield of the pod. The contents of leaf starch were greatest under R:B=3:7LEDs. The numbers of pods and yields were greatest under R:B=3:7LEDs than those grown under other LEDs3. We studied the effects of LED light on growth of cucumber seedlings, the results showed that the fresh weight, dry weight, leaf area, content of chlorophyll, content of soluble-protein, free amino acids were greatest under R:B=7:3LEDs. It can be used as a supplementary light source for cucumber production in the greenhouse. The plant height, contents of soluble-sugar and starch of cucumber seedlings were greatest under the red LED light. The fresh weight, dry weight and leaf area were greatest under R:B=7:3LEDs. The contents of sucrose were greatest under R:B=1:1LEDs. The contents of chlorophyll and soluble-protein were greatest under R:B=3:7LEDs. Root activity was greatest under R:B=3:7LEDs. The contents of free amino acids were greatest under the blue LED light.In conclusion, peanut was able to flower and fructifying under fluorescent lamps. We can control the growth progress of peanut by regulating the light source. The effects of LEDs on the growth of peanut were different. R:B=7:3LEDs was greatest for the growth of peanut seedlings. R:B=1:1LEDs was better for the flowering of peanut. R:B=3:7LEDs was greatest for the growth of pod and the yield improvements of peanut. The effects of LEDs on growth of cucumber seedlings showed that the R:B=7:3LEDs was better for the growth of cucumber seedlings. It can be used as a supplementary light source for cucumber seedlings cultivation in facilities.