Growth Inhibition, Seedling Damage, and Antioxidant Change of Cucumber Plug-transplants in Response to UV Spectra and Irradiation Timing

The objectives of this study were to determine the effect of UV spectra (B-UV: 274-400 nm or F-UV: 286-400 nm) and irradiation timing (at day or night) on growth inhibition, seedling damage, and antioxidant change in cucumber (Cucumis sativus L. cv. Garakmanchun) plug-transplants. B-UV (274-400 nm) significantly inhibited plant height and internode length; however, it increased ion leakage and lipid peroxidation, and decreased photosynthetic pigments, resulting in leaf necrosis and wrinkle regardless of irradiation timing. While F-UV (286-400 nm) did not cause plant damage such as leaf necrosis and wrinkle regardless of irradiation timing, it significantly inhibited plant height and internode length by 24% and by 21%, respectively and simultaneously increased the content of ascorbic acid and total phenolic compounds. Our results suggest that F-UV irradiation may be desirable for controlling the over-growth in cucumber plug-transplants. KCI Citation Count: 5