- Fluorescent dyes were incorporated into plastic sheets used as greenhouse covers. These dyes efficiently convert light from the green part of the spectrum into red light. When under field conditions, the use of the fluorescent sheets increased the agricultural yields of Gypsophila paniculata. The rate at which the changes in plant development were induced suggests that they were primarily due to a morphogenetic response of the plants to the increased red/far-red ratio of the light transmitted through the fluorescent sheets. The modified morphogenesis was typical of plants that are subjected to reduced competition by neighbours, and this includes the investment of a higher proportion of their resources in photosynthesis and reproduction. The spectral modifications caused by the new plastic covers could also increase the rate of photosynthesis.