@article{oai:mie-u.repo.nii.ac.jp:00010227,
 author = {向阪, 信一 and Kosaka, Shinichi and 洞口, 公俊 and Horaguchi, Kimitoshi and 齋藤, 直樹 and Saito, Naoki and 上條, 和彦 and Kamijyo, Kazuhiko and 村上, 克介 and Murakami, Katsusuke},
 issue = {2},
 journal = {照明学会誌},
 month = {Feb},
 note = {application/pdf, A supplemental lighting system was installed at a large-scale seedling greenhouse (12.5 m x 45 m), which supplies high quality and large quantity of seedlings to farmers through out the year. A test experiment of supplemental lighting for seedlings in this house was performed during the rainy season and winter-early spring to prepare for planting, when sunshine is sometimes insufficient. A mercury-free high pressure sodium lamp of 400W with a red to far-red photon flux (R/FR PF) ratio of 1.1 was developed and manufactured for this experiment. The average PPFD was 100µmol m⁻² s⁻¹. The experimental plants were lettuce, broccoli, and cabbage. In both rainy and winter-early spring experiments, we found that supplemental lighting was effective for seedling growth. Significant supplemental lighting effects in the rainy season were found for broccoli. Top fresh weights of both a 2h lit area before sunrise and after sunset were 30-60% greater than those of the non-lit area.
 A drop test of lettuce demonstrated that the remaining ratio of soil of both a 2h lit area before sunrise and after sunset were about 87%, and those of the non-lit areas were about 78%. Thus, good growth in roots was found. A significant supplemental lighting effect in winter-early spring was found in the lettuce experiment. Top fresh weights of both a 3h lit area before sunrise and after sunset were 165-200% greater than those of the non-lit area. In winter-early spring experiments, a clear difference between a 3h lit area before sunrise and after sunset was not found.},
 pages = {87--93},
 title = {野菜苗の育苗補光による成長の促進},
 volume = {91},
 year = {2007}
}