Stillwater, OK - Lettuce is one of the most important leafy vegetables in the United States, and it is subjected to a decrease in edible quality when cultivated in environments with hot temperatures and increased daylength. Specifically, bitter-tasting compounds called sesquiterpene lactones (SLs) accumulate in certain cultivars and lettuce market types, especially during the bolting stage.
A new study from Oklahoma State University highlights how seasonal temperature fluctuations impact the concentration of sesquiterpene lactones and sugars in hydroponically grown lettuce. These findings provide critical insights for optimizing lettuce quality, flavor, and nutritional composition in controlled-environment agriculture.
Sesquiterpene lactones contribute to the characteristic bitterness of lettuce, while sugar levels influence sweetness and overall taste. This research examines how variations in seasonal temperatures affect the balance of these compounds, potentially guiding growers in fine-tuning production strategies to achieve desired flavor profiles. Understanding these temperature-driven changes can also enhance post-harvest quality and marketability.
By leveraging these insights, hydroponic growers can refine environmental controls to produce lettuce with consistent taste and quality year-round. This study supports advancements in precision agriculture, helping to optimize controlled-environment farming for both consumer preference and industry demand.
Author Mason McLemore earned his Master of Science degree in Horticulture with a specialization in Extraction Science from Oklahoma State University in 2025. He currently serves as Operations Manager and manufacturing Manager at Cresco Labs.
Dr. Kathi is an Assistant Professor of Small Farms and Urban Horticulture in the Department of Horticulture & Landscape Architecture at Oklahoma State University. She specializes in sustainable vegetable crop production, nutrient management, biofortification of nutrients in plants, controlled environment crop production, efficient resource utilization, and innovative teaching strategies.
The full story can be found on the ASHS HortScience electronic journal website at: https://doi.org/10.21273/HORTSCI18393-24
Established in 1903, the American Society for Horticultural Science is recognized around the world as one of the most respected and influential professional societies for horticultural scientists. ASHS is committed to promoting and encouraging national and international interest in scientific research and education in all branches of horticulture.
Comprised of thousands of members worldwide, ASHS represents a broad cross-section of the horticultural community - scientists, educators, students, landscape and turf managers, government, extension agents and industry professionals. ASHS members focus on practices and problems in horticulture: breeding, propagation, production and management, harvesting, handling and storage, processing, marketing and use of horticultural plants and products. To learn more, visit ashs.org.
