Influence of the Sunlike Light Spectral Composition on Radish in Controlled Environment Agriculture: Morphophysiological Characteristics and Diffuse Reflection Indices of Leaves

Creating an optimal light environment for different crops is crucial for achieving high yields under controlled environment agriculture conditions. Currently, there are no optimal technologies, including lighting technologies, for growing root crops (in particular radish) in CEA (Controlled Environment Agriculture). This study examined the effects of HPS (High-pressure sodium vapor lamps) and three original sunlike full-spectrum LED lamps on the morphophysiological characteristics and the diffuse reflectance indices of the leaves of two contrast radish cultivars. It was found that a higher blue light content (24%) in the spectrum of the LED 3 lamp contributed to the formation of radish plants with a more compact leaf rosette and maximum yield of roots (up to 19%) compared to the other two types of LED lamps. When treated with LED 3, photosynthesis efficiency was probably higher compared to LED 1 and LED 2, which led to a significant decrease in reflected radiation, especially in the blue and red ranges (by 5–143% and 32–86%, respectively). It was found that the genotype had a significant effect on all morphophysiological parameters of radish, while lighting treatment only affected the integral parameters (Pr—proportion of root crop, and Ai—attraction index) and leaf thickness. However, lighting treatment exhibited a greater impact on leaf reflection indices compared to the genotype, especially those related to chlorophyll content. The results of the study indicate that LED 3 lamps, simulating natural light at midday, are suitable for the production of radish root crops under CEA conditions.