Effects of different red and blue light proportions on seedling production of flue-cured tobacco in multilayer system

Abstract

Effects of six different proportions of red and blue light of LED(light emitting diode) on seedling quality in multilayer system were studied. Two out of six proportions were selected to determine their impact on tobacco plant growth and tobacco leaf yield and quality. Results showed that light intensity had an enhanced trend with increase of proportion of blue light. The seedling rate under four proportions of red and blue light(1:1, 1:2, 1:3 and 1:4) was significantly higher than that under natural light. Dry matter accumulation was high, but seedling quality was similar to natural light. Chlorophyll content under LED light was significantly higher than that under natural light, but root activity under LED light was significantly lower. In addition, root activity under red and blue light with proportions of 1:1 and 1:4 was significantly stronger than that with other proportions. Tobacco plants with LED light treatment grew slow in root extending stage, and grew faster afterwards, and showed no significant difference with those under natural light treatment at maturing stage. The economic characters and chemical compositions of tobacco leaves under LED light treatments showed no significant difference with those under natural light. It is concluded that red and blue light with proportions of 1:1 and 1:4 could increase seedling rate and chlorophyll content of seedling leaves, and promote accumulation of dry matter.