Effects of Supplemental Light on Growth, Physiology, and Quality of Chili Peppers Cultivated in Solar Greenhouse

  Objective  Effects of supplemental light on the growth, photosynthesis, and quality of chili peppers cultivated in a solar greenhouse were studied.

  Method  In the greenhouse, Chili Pepper 37-94 plants were exposed to supplemental light emitted from LEDs at　red ∶ blue=5 ∶ 1,LEDs at red ∶ blue ∶ white=3 ∶ 1 ∶ 1), or a plant supplementary lamp for observations and measurements on the responses of the plants.

  Result  The plant height, stem girth, leaf length, leaf width, and chlorophyll content of the treated plants were significantly greater than those of control, Under the LEDs at red ∶ blue ∶ white=3 ∶ 1 ∶ 1 treatment, the net leaf photosynthetic rate increased by 63.72%, and the contents of soluble sugar, soluble protein, and Vc of the chilis rose 70%, 77%, and 8.2%, respectively, over those of control. Among the 3 treatments, LEDs at red ∶ blue=5 ∶ 1 produced the highest Gs, Ci, and Tr in the leaves with increases of 73.33%, 12.94%, and 35.83, respectively, over those of control.

  Conclusion  Exposure of LEDs at red ∶ blue ∶ white=3 ∶ 1 ∶ 1 promoted the photosynthesis increasing the chlorophyll formation and accumulation in the chili pepper plants that enhanced the plant growth and improved chili quality.