Spectrum conversion film for regulation of plant growth

In order to regulate the plant growth, we newly developed the spectrum conversion films (red film and blue film). The red film can convert the blue-green light (450-550nm) into the red light (600-700 nm), and the blue film can convert the ultraviolet (UV)-violet light (350-450 nm) into the blue-green light. The effect of covering plants with these films on leaf photosynthesis, plant growth and seed germination were examined in three species of plants under the natural light. Leaf photosynthesis of radish was slightly accelerated in the red film. Fresh and dry weights of root of radish were higher in the red film, and were up to 1.5 times higher than that in the blue and clear films. Therefore, the acceleration of root growth through the activation of leaf photosynthesis was observed in the red film. Fresh and dry weights of shoot of Welsh onion were also higher in the red film. On the other hand, leaf elongation was accelerated in the blue film, and this was observed in radish and Welsh onion. The seed germination of Blue Star (Oxypetalum caeruleurri) was accelerated under the red film, and reached to 98%. From these results, the red film enables the accelerations of leaf photosynthesis and seed germination, and the blue film accelerates the leaf elongation. Therefore, the spectrum conversion films are applicable to regulate the plant growth in plant productions.