Effects of Light-Emitting Diodes on the Growth of Peanut Plants

Light-emitting diodes (LEDs) are a new type of energy-saving light source, and their effects on the growth of peanut (Arachis hypogaea L.) plants remain unknown. This study aimed to determine the effects of LEDs on the growth of peanut plants. Plants were exposed to 300 mu mol/m(2)/s photosynthetic photon flux density under a 12 h photoperiod and six different treatments: monochromatic red (R) LED, monochromatic blue (B) LED, three R plus B LED mixtures (7: 3, 1: 1, 3: 7), and fluorescent lamps (FL). At the seedling stage, the fresh weight, dry weight, height, root length, and chlorophyll content were greatest in plants under R/B = 7: 3 light. At the blooming stage, the starch concentration and soluble sugars were greatest in plants under R light followed by those under R/B = 1: 1 light, the sucrose concentration was greatest under R/B = 7: 3 light followed by R/B = 1: 1 light, and the chlorophyll concentration was greatest under R/B = 1: 1 light. These results showed that R/B = 1: 1 light was conducive to peanut growth at the blooming stage. At the pod-setting stage, the sucrose concentration and soluble sugars were greatest in plants under R/B = 1: 1 light, and the starch content was greatest in plants under R/B = 3: 7 light. The pod numbers and yields were greater in plants under R/B = 3: 7 light than in plants under the other LED lights. R/B = 3: 7 light was best for pod growth and yield and could be used as an alternative light source for peanut industry cultivation.