The effects on the growth of pea seedlings under different red and blue photons ratio Pc-LEDs lighting

This paper presents a new method to provide the red and blue light for plants with red phosphor-converted blue LED chips, or pc-LEDs. By adjusting the proportion of phosphor powder in silicone binder of coating layer to realize the different red to blue ratio in plant lighting application. In this work, the effect of light on the growth of pea seedlings was studied under the condition of which the Photosynthetic Photon Flux Density (PPFD) is 70μmol·m−2·s−1, the red and blue photons ratios is 2.3: 1, 3: 1, 4: 1, 6: 1, 7: 1, 8: 1, and 9: 1 and the photoperiod is 14h. The pea seedlings were cut on the 20th day, the experiment results showed that the pea seedling have the maximum height, stem and leaf dry weight at the red to blue photon ratio 9: 1. The chlorophyll content reached the maximum quantity under the red and blue photons ratios 7: 1. This experiment convinced the feasibility of pc-LEDs for plant illumination, and verified that the red light could promote the elongation of stem and the accumulation of organic matter, while, the red and blue photons ratios 7: 1 is more conducive to the synthesis of chlorophyll.