Panel Discussion 2: Leafy Greens Root Health Management

Dr. Anna Testen is a Research Plant Pathologist with the USDA-ARS Application Technology Research Unit (ATRU) in Wooster, OH.

Dr. Testen’s research focuses on management of diseases of specialty crops produced in controlled environment agriculture systems, ranging from high tunnels to vertical farms. This research focuses on developing non-chemical methods of disease management, such as anaerobic soil disinfestation and biological control.

She has expertise in plant disease management, disease diagnostics and monitoring, specialty crop production, seed pathology, and international agriculture.

Austin Smith has been with Grodan for six years as an Account Manager, serving the U.S. commercial vegetable market. With initial interests in water and energy, he found his way to CEA when someone posed the question, “Have you ever thought about food?”.  He then began his career in 2014 at the University of Arizona’s CEAC, where his passion was cultivated through higher education and academic research. While he often jokes about "selling rocks", Grodan's stone wool substrates are meticulously engineered to provide unparalleled uniformity, cleanliness, and predictability.

Dr. Kyle Freedman is the Global Segment Manager CEA for Jiffy Group responsible for providing technical guidance and support to Jiffy's global CEA customers and helping to drive market expansion. Kyle holds a BA in Philosophy from the University of North Carolina Chapel Hill. He earned his MSc. in International Agriculture Development from the University of California at Davis with a concentration in Horticulture and Agronomy where his research focused on climate-smart, small-scale postharvest processing systems of coffee in Honduras.

He is currently a PhD Candidate at North Carolina State University in the Department of Horticultural Sciences where his research focused on the development of a new grapevine production system called Precise Indoor Vine Conditioning (PIVC) in which young grapevines are conditioned with supplemental light to produce fruit in their first season of field transplanting. With 13+ years of experience, Kyle was previously a Sr. Project Management Specialist at RTI International prior to graduate school where he was a part of their global food security and agriculture team managing over $150 million in USAID and USDA development projects in East Africa and Southeast Asia.

Dr. Paul Rutten is the CEO and Founder of Concert Bio, a biotech startup dedicated to helping CEA growers understand and improve their plant microbiome. Paul is Dutch, but did his PhD at the University of Oxford, where he studied plant-microbe interactions.

Through microbiome monitoring service for growers, Concert Bio has collected over 20,000 samples. Using this data, they recently developed their first beneficial microbe product, Overture™ (US brand name Prelude™). These microbes have since been validated extensively by major growers in the US and Europe, as well as Dutch trial centres such as Delpy, Vertify and Horti-Tech.

Dr. Soledad Benitez Ponce is an Associate Professor in the Department of Plant Pathology at The Ohio State University (OSU), where she leads the Plant Bacteriology and Agricultural Microbiomes Lab. Her research focuses on the diversity and function of soil and plant-associated microbial communities, specifically examining how agricultural management practices—such as crop rotation, cover crops, and hydroponic production—influence plant health and sustainability. Originally from Ecuador, she earned her BS in Biological Sciences from Pontificia Universidad Católica del Ecuador before completing PhD in Plant Pathology at OSU. Dr. Benitez Ponce has extensive experience in microbial ecology and plant pathology, having held teaching and research positions in Ecuador and postdoctoral fellowships at Duke University and the USDA. Today, she integrates high-throughput molecular techniques with field and greenhouse experimentation to better understand the ecology of plant-associated microorganisms with the goal to optimize plant-microbial associations that promote crop health, productivity and sustainability.

Hydroponic related research:

Hydroponic production, including of leafy greens, is a growing and dynamic industry. In hydroponics, roots are in continuous contact with a nutrient solution standardized to maximize crop biomass. In our laboratory we are interested in how these conditions that maximize crop growth are influencing microbes, and their function in production settings. The Benitez Ponce lab recently documented variability in leafy green hydroponic operations, production practices (e.g., type of substrate used and sanitation frequency), and automation in Ohio. They also found that system design and sampled compartments are the main drivers of microbial community composition, and that EC, pH, greenhouse temperature, and season contribute to community differentiation across facilities. In addition, they are exploring the functional contributions of novel bacteria (recovered from nutrient solution) to hydroponic system health, and parameters that influence incidence and dynamics of Pythium root rot. 

Vijay Rapaka, Ph.D. is the Director of Global Grower Operations and Research for Smither‑Oasis, where he leads the Oasis Grower Solutions division. In this role, Dr. Rapaka oversees an international team supporting growers worldwide, with a strong focus on advancing solutions for CEA, including vertical farming, greenhouse production, and precision hydroponic systems.

During his tenure at Smither‑Oasis, Dr. Rapaka has held several key roles, including Corporate Grower Research Manager and Senior Grower Research Scientist. He was the lead research scientist on the team that developed a new generation of engineered substrate technologies, including those behind OASIS® AeroSubstrates™—climate‑ and crop‑optimized precision hydroponic substrates designed specifically to meet the performance, consistency, and scalability demands of modern CEA operations.

He holds a Master’s degree in Plant Physiology and a Ph.D. in Ornamental Horticulture, with postdoctoral research in Postharvest Physiology and Adventitious Rooting. Dr. Rapaka is actively engaged in advancing horticultural research and innovation, serving on the Board of Trustees for the American Floral Endowment (AFE) and as Research Chair for AFE’s Research Committee.