Research into photomorphogenesis, the process of how plants change their development in response to light wavelengths, has become of particular interest to horticultural scientists. Previously, the most popular understanding of how plants use light was from the model of photon absorption by chlorophyll. While this model is a great visual for photosynthesis, it leaves out a large portion that explains how plants see the world and make decisions.
Different wavelengths of light are used by the plant to make choices about their environment. Some common examples of photomorphogenesis are seen when plants lean towards light sources, change color or shape with the seasons, and know just when to flower so their seeds will germinate in the spring. Plants use the ratio of red light to far red light to sense when they are in the shade, and respond by stretching to be longer and taller in an attempt to reach the sun. This shade avoidance response is already being used by horticulturalists growing greens such as lettuce, where long leaves are the goal. But what about farmers trying to grow dense, heavily fruited crops, or create specific flavor profiles, shapes, growing periods, or other features? Each color plays a part in photosynthesis and photomorphogenesis, and an understanding of the light recipe is a crucial aspect of horticulture.