SUMMER 2024
Increasing global temperatures have made breeding crops for drought tolerance an utmost priority for protecting global food security. However, crop water use dynamics are poorly understood especially in regards to physiology and plant hydraulics. In order to better select and understand mechanisms for drought tolerance, methods of measuring water use at a high throughput will be necessary.
Working with Dr. Daisuke Sugiura in the crop science laboratory at Nagoya University I worked on methods of evaluating transpiration and plant water use in the field and in the lab through the use of arduino based microcontrollers.
The first part of the project involved the use of non intrusive sap-flow sensors on rice and soybeans to measure water use in the plant from rice paddies and soybean fields. The sensors were utilized as a part of a solar powered Arduino-based microcontroller system I soldered and programmed from Dr. Sugiura’s teachings and course material. The microcontroller was programmed to connect to a pocket wi-fi and to continually transmit measurements of sap-flow data throughout the plant’s growth.
The sensor was fitted upon the stem of the plant with an insulated collar and took a temperature reading above and below short heat pulses. With this method convection of heat by the moving sap causes the center of the heat pulse to move with velocity proportional to the sap flow. So essentially the difference between the temperature reading upstream and downstream of the heat pulse gives us a proportional sap flow reading.
The second part of the study was establishing a high-pressure flow method system that used the same sensor to collect sap velocity coupled with a pressurized system that measured gravimetric measurements of sap flow. From the two measurements an empirical calibration can be made.
The system was based on a design from Clearwater et al., 2009 and took gravimetric measurement by running pressurized water through an excised stem (soybean stems I collected in the field) which was then measured by a different sensor and logged by a similar data logger. I would start off at around 250-300kpa and would lower it by 50 kpa every 15-30 minutes.
The original system created by Dr. Sugiura was only used by him two times before I arrived in Nagoya so we ended up having multiple iterations of the system but by the time I had left we were able to successfully create calibrations of two excised stems simultaneously.
Ultimately we achieved what we set out to do in my short stay at Nagoya and I was able to get to help out with other exciting projects like a cotton experiment studying the effects of a novel suppressant where I got to collaborate with Dr. Aihara. I am excited to see how Dr. Sugiura further develops both systems in the future and I would like to thank him for being an amazing mentor to me and making me feel just as comfortable and welcomed as at my home university.
Beyond research, the personal relationships I made and the bonds I developed were just as valuable. Going out to get sushi or getting ramen together with other students in the lab after field work are memories I will forever cherish. I cannot thank both Dr. Tucker, the CALS pack abroad program, and Nagoya University for giving me the opportunity to participate in this research at this incredible institution.
Clearwater, M. J., Luo, Z., Mazzeo, M., & Dichio, B. (2009). An external heat pulse method for measurement of sap flow through fruit pedicels, leaf petioles and other small-diameter stems. Plant, Cell and Environment, 32(12), 1652–1663. https://doi.org/10.1111/j.1365-3040.2009.02026.x
Research Pack Abroad provides undergraduate students international research experience – working side-by-side with scientists and immersed in another culture. Students are connected with a host international research institution, where they conduct research for at least 2 months during the summer.