Early Detection of Botrytis Cinerea Growth via GHz Ultrasonic Imaging of Agar Depletion

Botrytis Cinerea is a destructive fungal pathogen responsible for significant agricultural losses worldwide. In this paper, we demonstrate a GHz ultrasonic imaging method to detect early fungal growth by monitoring nutrient agar depletion. A sessile droplet drying model was developed to establish baseline evaporation dynamics, which were validated experimentally. Using a custom-built portable 1.85 GHz ultrasonic imager provided by Geegah Inc., we correlated return voltage signals with agar thickness, allowing quantification of Botrytis-induced agar depletion. Control droplets exhibited predictable drying and stabilization, while inoculated samples displayed accelerated agar reduction and demonstratable thickness variation in comparison to control experiments. These results suggest that GHz ultrasonic imaging offers potential for a rapid, portable, easy to use platform for on-site pathogen detection, enabling earlier intervention compared to traditional methods.