光質の異なる蛍光灯連続照明下でのピーマンの生育と乾物生産

抄録

Effects of continuous lighting of fluorescent lamps with different light qualities on growth and dry matter production of pepper plants were investigated. Stem length was longest in red light, followed by white light and shortest in blue light. Comparison of continuous lighting (CL) and daily 12 hr-lighting (DL) in red and blue lights showed that stem length was longest in the case of CL-red, followed by DL-red, CL-blue, and shortest in the case of DL-blue.
Twenty days treatment showed that plant height of CL-blue was reduced by 70% of that of CL-red. These results indicate that blue light strongly inhibits stem elongation. However, leaf color turned dark green in CL-blue and lateral shoots sprouted earlier, on 1 st, 2 nd, 3 rd and 4 th nodes. These phenomena were not observed in the case of DL-blue.
Leaf area and dry weight of the shoot were highest in the case of CL-red, and corresponded to 1.7 and 1.4 times of the amount in CL-blue, respectively. However, photosynthetic rate on leaf area basis was similar among the treatments. Leaf area was 1.7 times larger in the case of CL-red than that of DL-red, and the ratio CL/DL in dry weight of the shoot was 2.6 which exceeded 2.0, the ratio of irradiated light energy. This result suggests that dry matter production of pepper plants involved in light use efficiency can be increased by continuous lighting of 100 μmol m^-2s^-1 PPFD.