US (IN): How LED lighting treatments affect greenhouse tomato quality

To satisfy increasing consumer demand for locally grown, fresh tomatoes during off-seasons, greenhouse tomato growers often need to rely on supplemental lighting. Tomato growers are looking to light-emitting diodes (LEDs), favored for their energy-saving potential, as an alternative to high-pressure sodium lamps (HPS) in greenhouse operations. A recent study offers new information about the feasibility of using LEDs in greenhouse tomato operations.

Michael Dzakovich, Celina Gómez, and Cary Mitchell from the Department of Horticulture and Landscape Architecture at Purdue University published the study of supplemental lighting experiments in HortScience (October 2015). They noted that light-emitting diodes are becoming a viable alternative to high-pressure sodium supplementation. "There is great interest in (LEDs) potential to influence the phytochemical and flavor profile of various high-value crops," the authors said. "However, little fruit quality-attribute work with LEDs has been done on a long-duration, full grow-out of tomatoes."

The researchers conducted three separate studies to investigate the effect of supplemental light quantity and quality on greenhouse-grown tomatoes. Plants were grown either with natural solar radiation only (the control), natural solar radiation plus supplemental lighting from high-pressure sodium lamps, or natural solar radiation plus supplemental light from intracanopy (IC) LED towers. The scientists analyzed plant responses by collecting chromacity, Brix, titratable acidity, electrical conductivity, and pH measurements. "Contrary to our hypothesis, fruit quality was largely unaffected by direct, IC supplemental lighting," the authors said.

Read the full report at Science Codex