Non-destructive field phenotyping platform combining sap flow sensing and thermal imaging for whole-plant canopy conductance monitoring

Overview

This solution addresses a long-standing gap in field-based plant phenotyping: measuring whole-plant canopy conductance to water without destroying the plant or relying solely on labor-intensive gravimetric methods. Canopy conductance is directly linked to total carbon fixation and nutrient uptake, making it a critical trait for breeding programs targeting drought tolerance and resource-use efficiency. By combining stem sap flow sensors with UAV-based thermal imaging, the platform delivers continuous, non-destructive, and real-time monitoring of plant water use across the growing season. The technology is being developed to support high-throughput screening of diverse germplasm collections, enabling researchers and breeders to identify superior lines more efficiently.

Technical specifications

• Sap flow sensing: Stem-mounted sap flow meters measure the rate of water movement through the plant (grams per hour), providing a direct proxy for whole-plant water use.
• Gravimetric validation: High-precision balances and dataloggers independently confirm sap flow readings by tracking pot weight loss over time, achieving a correlation of R² = 0.85 to 0.93.
• Thermal imaging integration: Canopy thermal imaging captures heat signatures that indicate canopy conductance under stress, adding a complementary, non-contact measurement layer.
• Field deployment: UAV-based thermal imaging is scheduled at weekly intervals across growth stages, enabling season-long monitoring under normal and drought conditions.
• Experimental design: Validated on growth-chamber-grown soybean plants (n = 6) over 10 days; future validation will scale to 30 diverse USDA soybean accessions under three soil drying levels, followed by a field study on four selected lines.

Technology readiness level

The technology is at an early-to-mid stage of development. Proof-of-concept validation has been completed in a controlled growth-chamber environment, demonstrating strong agreement between sap flow measurements and gravimetric water-use measurements. The next phase involves scaling to 30 diverse soybean accessions under controlled soil drying conditions, followed by a multi-line field study integrating sap flow sensors with UAV-based thermal imaging under normal and drought conditions. The platform is not yet commercially available but is positioned for collaboration with breeding programs, agricultural technology developers, and research organizations focused on crop improvement and drought resilience.