Uvalde, TX- A recent study by researchers at Texas A&M AgriLife Research and Extension Center investigates how humic substances (HS) and light-emitting diode (LED) lighting influence tomato (Solanum lycopersicum) transplant growth and subsequent fruit production. The study was part of a project supported by Qatar National Research Fund, aimed at improving tomato productivity in hot-climate regions. Dr. Daniel Leskovar's group has extensive research experience with HS, which motivated a deeper investigation into their potential benefits.
Humic substances (HS) are the largest component of soil organic matter, consisting of complex high-molecular-weight aggregates. They are classified into humin, humic acid, and fulvic acid based on solubility at different pH levels. HS improve vegetable production by enhancing biomass, nutrient and water use efficiency, and crop yield. These benefits stem from their ability to improve soil structure, increase cation exchange capacity, buffer soil pH, and enhance nutrient bioavailability. However, variations in HS composition, source materials, and environmental conditions can lead to different effects on plant growth, especially under abiotic stress.
Researchers also tested various LED light spectra, including different blue (B) and red (R) light ratios, alongside HS treatments. The study found that tomato seedlings grown under a 50B:50R LED light ratio exhibited significant early growth improvements when treated with HS. However, these early-stage benefits did not consistently lead to increased fruit yield or improved fruit quality after transplantation.
These findings highlight the potential of combining HS and LED lighting to enhance early tomato development while emphasizing the need for further research to determine long-term effects on fruit production.
The research team included Chungkeun Lee (lead author), Asmita Nagila, Joshua Harvey, Seunghyun Choi,and Daniel Leskovar. The study was part of a project supported by Qatar National Research Fund, aimed at improving tomato productivity in hot-climate regions. Dr. Daniel Leskovar's group has extensive research experience with HS, which motivated a deeper investigation into their potential benefits.
According to the author, "Our research demonstrated that the combined application of
HS and LED lighting can help tomato transplant nursery growers save time and costs by
achieving the desired quality more quickly through enhanced seedling vigor, despite
limited long-term effects on growth and fruit production."
Dr. Leskovar is Professor of Physiology and center director of the Texas A&M Agrilife Research and Extension Center. He is also the current president of the American Society for Horticultural Science.
The full story can be found on the ASHS HortScience electronic journal website at: https://doi.org/10.21273/HORTSCI18343-24
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.
