New Sensor Detects Peanut-Killing Fungus Days Before Symptoms Appear

Researchers at Virginia Tech have built an electrochemical sensor that can detect Sclerotinia blight, a fungal disease that has devastated peanut crops, days before physical symptoms appear. Severe outbreaks of the disease, caused by the fungus Sclerotinia minor, have caused yield losses of up to 50%, and the pathogen can survive in soil for years once established.

The sensor, described in a paper in ACS Agricultural Science & Technology, is built from 3D-printed resin substrates and platinum electrodes. Sap extracted from a peanut plant is placed on the sensor, which detects elevated levels of oxalic acid -- a chemical that plants infected with Sclerotinia minor produce abundantly. It can detect the pathogen as early as five days after infection, compared with the two months it can take for physical symptoms to appear; farmers have historically relied on time-consuming physical inspections that often catch the disease too late to stop its spread.

The sensor was developed by Frank Erukainure, a doctoral candidate in Virginia Tech's Department of Biological Systems Engineering, and his adviser Abhilash Chandel, an assistant professor of precision agriculture and data management who leads the university's Digital Ag Technologies Lab. Erukainure's work on the project earned him the 2026 Boyd-Scott Graduate Research Award from the American Society of Agricultural and Biological Engineers. In 2024, farmers in southeastern Virginia harvested about 30,000 acres of peanuts, worth a cumulative $37.4 million.

The sensor's early-detection ability has been validated in greenhouse trials, though additional field testing is needed before it can be deployed on farms; researchers plan to pilot it with growers in Virginia's Tidewater region next year. "Technologies like these are transforming plant production," Chandel said. "By monitoring plant health in real-time, these sensors enable proactive intervention, improving crop resilience, productivity, and sustainability."