If there's one thing that has become clear in horticulture, it is that there's more to lighting than switching on the most efficient LED lights that you can find. In a new white paper, Sollum Technologies explains why light quality is important.
Previously Sollum whitepapers educated growers on the seasonal and daily changes to light quality (i.e., spectrum) and quantity (i.e., intensity and photoperiod), which significantly impact plant growth and development. "While the impact of light quantity may appear more obvious, that of light quality is more abstract due to the nanoscopic nature of light", says Rose Seguin, agronomist with Sollum Technologies. "With light quantity, we can easily discern whether light is more intense and whether the day is longer or shorter. With light quality, we are considering the spectrum thus the decomposition of light into different colors, their wavelengths, and the relative amounts of each wavelength."
She explains how light quality varies both seasonally and daily as weather conditions and the atmospheric path traveled by light impacts the absorption and scattering of different wavelengths, resulting in a discrepancy between pure sunlight and what reaches the plant canopy. "Considering spectrum in terms of photon ratios has made it easier to study the impacts of light quality on plant growth and development, with the main ratios of interest being red to blue (R:B) and red to far-red (R:FR). Researchers are also beginning to study blue to green (B:G) and blue to far-red (B:FR), among others", she says.
Tool to guide plant development
"Understanding the morphological impacts of different photo ratios allows a grower to harness these ratios as a tool to guide plant development", she says. "For example, the ratio of R:FR light has been extensively studied due to its impacts on stem elongation, apical dominance, leaf expansion, photosynthetic efficiency, and flowering response in shortday and long-day plants. Controlling the R:FR ratio thus allows control over plant morphology architecture."
Sollum Technologies created a smart LED lighting solution that dynamically recreates the full spectrum of the sun's natural light. Sollum™ works closely with its clients and research partners to create recipes that are adapted to the growth cycle of each crop, regardless of its native climate or the location of the greenhouse. In order to help growers make the most out of all these options, Rose explains what the effects of light can be.