Control of Stretching of Cucumber and Tomato Plug Seedlings Using Supplemental Light

초록

This study was initiated to select the most efficient EOD light treatment for the control of stretching of cucumber and tomato plug seedlings in the plant factory using four different EOD light qualities, three light intensities, and four different EOD light irradiation period treatments. Compared with control, R, R LED, and B LED light treatments decreased the plant seedling height 23.8%, 25.1% and 15.6% in cucumber and 14.3%, 15.6% and 8.9% in tomato, respectively; in contrast, FR LED light irradiation increased plant height about 21.9% in cucumber and 15.1% in tomato. The seedlings treated with R and FR LED lights had significantly higher values of compactness than those of other treatments. R and R LED light treatments showed the lower T/R ratio than other treatments in cucumber and tomato. In the irradiation period experiment, 10, 30, 60, and 120 minutes of R irradiation reduced the plant heights about 8.8%, 14.0%, 25.5% and 30.2% in cucumber and 11.4%, 18.0%, 22.5%, and 25% in tomato plant seedling, respectively. As the irradiation period increased, both plant seedlings showed the lowest T/R ratio and the highest compactness. The seedlings treated with 2, 8, and 16 μmol･s-1･m-2 of R light intensities reduced 11.7%, 15.3%, and 22.3% of cucumber seedling heights and 7.8%, 12.4%, and 14.8% of tomato seedling heights after 30 d and 50 d of treatments, respectively. The higher intensity of R light had the shorter lengths of hypocotyls and internodes in both plant seedlings. Lengths of petioles in both plant seedlings were significantly decreased by the EOD R light irradiation. Both plant seedlings treated with 8 μmol･s-1･m-2 of R light intensity had the lowest T/R ratio and the highest compactness.

키워드