Effect of Red and Blue Light on Cucumber Seedlings Grown in a Plant Factory

Light-emitting diodes (LEDs) have been regarded as the best artificial source of light for a plant factory. However, the effect of light quality on seedling production in such environments requires further study. On the basis of the practical application of light on cucumber seedlings (Ansha Company) in plant factories, the present investigation tracked and recorded the specific effects of red and blue light on the growth of the seedlings by analyzing the photo-biological mechanism involved. The growth parameters, as well as the photosynthetic characteristics of cucumber seedlings, were measured at different variations of light quality. The results showed that when the proportion of red light in the light source was higher than blue light, the height of the seedlings, leaf size, stem diameter, Dixon Quality Index (DQI), relative chlorophyll content, and the net photosynthetic rate were higher than those of the experimental group with a relatively high proportion of blue light. In the case of R7B3 (70% red light and 30% blue light), the stem diameter, DQI, and net photosynthetic rate of seedlings were 14%, 57%, and 22% higher than the minimum value, respectively. The present study analyzed the influence of red and blue light on plant growth characteristics during actual production and provides standardization for it.