By Blake Jackson
At Cornell’s Musgrave Research Farm, researchers are testing an unusual approach to monitoring crop nutrition: tomato plants that can visibly signal when they experience nitrogen deficiency.
The field trial is examining whether these genetically engineered “sentinel” plants could eventually help farmers detect nutrient stress more efficiently under real-world growing conditions, according to Henry C. Smith, communications specialist for Biological Systems at Cornell Research and Innovation.
The research was featured during the 2026 Aurora Farm Field Day on July 30, 2026, where visitors toured experiments focused on crop health, soil management, and digital agriculture. The event also gave researchers an opportunity to receive feedback from farmers, scientists, and potential collaborators.
“It’s an opportunity to have stakeholders and potential future collaborators come and actually see our technology, and to capture their ideas and questions,” said Abraham Stroock, Director of the Center for Research on Programmable Plant Systems (CROPPS) and Gordon L. Dibble ’50 Professor in the R.F. Smith School of Chemical and Biomolecular Engineering.
Known as “Red Alert” tomatoes, the experimental plants produce betanin, the red-purple pigment associated with beets, in their leaves and flowers when nitrogen becomes limited.
Researchers believe the visible response could eventually help growers identify nutrient shortages and make more targeted fertilizer applications, potentially lowering costs and reducing environmental impacts.
“It’s pretty unprecedented to have a nitrogen sensor like this that can show continuous nitrogen variation in real time,” said Sam Mosher, a doctoral student and CROPPS trainee leading the field trials.
The plants are intended to serve as indicators rather than food crops. Researchers are also exploring whether similar technology could eventually detect other stresses, including water shortages or phosphorus deficiency, and whether the approach could be adapted to crops such as maize.
This is CROPPS’ second field season evaluating the technology at Musgrave. In 2025, the tomato plants successfully distinguished low-nitrogen plots from adequately fertilized areas, although combining tomatoes with corn created management challenges.
This year, the tomatoes are growing in a separate plot under low, standard and recovery nitrogen treatments. Field conditions have added complexity, including powdery mildew and early heat. However, researchers observed that some plants recovered after nitrogen was restored.
Mosher is analyzing soil and leaf samples while the team uses drones and handheld spectrophotometers to measure plant color.
The researchers hope repeated field testing and grower feedback will help determine how many sentinel plants are needed, how farmers could interpret their signals and whether the technology can become a practical agricultural tool.
Photo Credit: gettyimages-bastetamn
Categories: New York, Crops, Fruits and Vegetables, Education