Near-UV radiation acts as a beneficial factor for physiological responses in cucumber plants

Growth and Yield of Tomato and Cucumber Plants in Polycarbonate or Glass Greenhouses

“…Similar experimental results were also reported for hydroponic eggplant grown under UV -blocking and UV -transmitting plastic films (Kittas et al, 2006). The effect of UV -A on the growth and development of young cucumber plants was found to be positive rather than negative in UV experiments conducted by Mitani -Sano and Tezuka (2013). The authors reported that, despite suppression of stem (hypocotyl) elongation and leaf area in young plants under UV radiation from black -light fluorescent lamps (with a peak at 352 nm), the plants developed thick stems (stubby hypocotyls) and leaves.…”

Effect of Different Monochromatic LEDs on the Environmental Adaptability of Spathiphyllum floribundum and Chrysanthemum morifolium

“…In this experiment, the net photosynthetic rate of C. morifolium under green light was significantly higher than under other monochromatic light, probably because red light and blue light were effectively absorbed by the plant surface, while green light may have reduced the potential light gradient inside the leaf and provided the energy for photosynthesis in deeper layers. Researchers have shown that chloroplast decline would occur because part of the membrane system was destroyed and because stomatal conductance was decreased, which would increase the intercellular carbon dioxide concentration, especially because carbon dioxide fixation was blocked, and a large amount of reactive oxygen species would accumulate [ 19 , 22 , 70 ]. Compared with other monochromatic light, the net photosynthetic rates of S. floribundum and C. morifolium were the lowest under UV-A light, which may be caused by UV-A light irradiation destroying the chloroplast system, causing the chlorophyll a, chlorophyll b, and chlorophyll a/b values to decrease, and ultimately the number of chloroplasts to decrease.…”

“…Two bands of UV light, UV-B (280–320 nm) and UV-C (100–280 nm), induce the production of free radicals, which can destroy plant DNA, proteins, lipids, chloroplasts, and photosynthetic pigments [ 18 , 19 ] and can inhibit plant photosynthesis and growth [ 18 , 20 , 21 ]. Other studies have found that near-UV light (300–400 nm) or UV-A (320–400 nm) can promote plant growth and physiological activity [ 22 , 23 ]. Some researchers pointed out that the chlorophyll in plant leaves absorbs very little green light, which, compared with blue and red light, has little effect on plant photosynthesis [ 24 , 25 , 26 ].…”