Our Team

GIULIA MARINO 

Professor of Cooperative Extension in Orchard Systems, Lab PI

Giulia is an Associate Professor of Cooperative Extension at the Department of Plant Sciences, UC Davis. Her research and extension focus on using physiological information to develop management practices that would improve efficiency of resource use and profitability of orchard systems. 

Dr. Marino completed her PhD at the University of Palermo, Italy, where she studied the physiology of alternate bearing in Pistacia vera L.. Her first post doc experience, in Italy, focused on proximate sensing and plant-based cultivar-specific water management in olive. She also worked on autochthonous germplasm conservation and agronomic characterization. In 2016 she started a post doc at the University of California (Davis) aiming to understand pistachio water use dynamics under saline-sodic stresses.

PAULA GUZMÁN-DELGADO

Professional Researcher, Lab PI

Paula is a Professional Researcher in the Department of Plant Sciences at UC Davis. Her research focuses on how plants respond to environmental conditions and management practices, with particular emphasis on water and carbon dynamics.

AMRIT POKHREL 

Ph.D. Student Researcher (University of California, Davis)

Amrit is a Ph.D. student at Horticulture and Agronomy Graduate Group, University of California Davis, and is co-advised by Dr. Giulia Marino, and Dr. Paula Guzman Delgado, and Dr. Troy Magney. He joined Tree System Lab in 2023 as an Assistant specialist and helped to manage Davis lab and projects for a year before starting his PhD. He is interested in integrating plant physiology and remote sensing. His project is currently focused on identifying physiological water stress indicators in orchard crops using proximal and remote sensing approaches. He received his BS in Agriculture from IAAS, Lamjung Campus, Nepal (2019) and MS in Crop and Soil Sciences (2023) from University of Georgia Tifton Campus. 
 

AILEEN SALAS

Graduate Student Researcher (University of California, Davis)

Aileen Salas is an M.S. student at UC Davis's Horticulture and Agronomy Graduate Group. She began her work with the Tree System Lab in May 2022 as a Student Intern, helping with various on-farm studies related to water stress and fruit development. She became skilled in performing and interpreting several physiological field measurements, such as stem water potential and leaf gas exchange.  Starting in September 2024, she is now co-advised by Dr. Paula Guzman Delgado and Dr. Giulia Marino, where she will continue to integrate plant physiology parameters for farm management through multi-site research projects across California, working with pistachios, almonds, cherries, and agave. She is also investigating fruit development and ripening processes in almonds. She graduated from Fresno State in December 2023 with a B.S. in Agricultural Plant Sciences and plans to graduate with her M.S. at UC Davis in June 2026. She is interested in doing on-farm/extension applied research and using a physiological approach to optimize orchard system management strategies. 

DONALD WILLIAMS III 

Graduate Student Researcher (Kearney Agricultural Research and Extension Center)

Kaya is a UC Davis student getting bachelors degrees in Sustainable Agriculture & Food Systems and Sustainable Environmental Design. She began working with the Tree Systems lab in January 2025 to learn more about extension work. Kaya presented at the UC Davis Undergraduate Research Conference on the lab’s study on agave growth in California. She was also responsible for the design and creation of extension outreach material for an olive deficit irrigation workshop. Kaya is excited to continue working over the summer and learn more about research and its practical application to farmers across the state.