Johanna Del Castillo Múnera

Assistant Professor of Cooperative Extension
Department of Plant Pathology
UC Davis

Dr. Johanna Del Castillo is the Cooperative Extension Specialist of greenhouse and nursery crops, in the Department of Plant Pathology at UC Davis.  Since 2020, she initiated the Greenhouse and Nursery Pathology research program  https://greenhousepathology.faculty.ucdavis.edu/.  She  is interested in implementing a system-based approach for disease management and proposing sustainable solutions—under a changing climate—to reduce pathogen risks in agriculture.  Her program studies  fungal and oomycete biology, population genetics, and community ecology. Relevant areas of research and extension include : 1) Validating and developing robust and improved diagnostics tools for Phytophthora detection in nurseries; 2) Assisting California restoration nurseries in the implementation of Best Management Practices (BMPs) to grow healthy nursery stock, following the Accreditation to Improve Restoration (AIR) program https://airnursery.ucdavis.edu/; 3) Characterizing pathogens and environmental conditions that trigger disease in greenhouse and nursery crops; 4) Disease diagnostics and management in nurseries.

Before this position, she worked as an Assistant Project Scientist at UC Davis, at Bayer Crop Sciences with biological controls and as a postdoctoral scholar at UC Davis and at the University of Maryland.  Del Castillo obtained her PhD in Plant Pathology from Michigan State University, where she worked at characterizing Pythium species from ornamental crops in the state, and her undergraduate and master’s degree in Microbiology  from Universidad de los Andes, in her native, Bogotá Colombia.  Her favorite native California plant is Coast Redwood (Sequoia sempervirens). 

David Fujino

Dave Fujino has served for more than 17 years as the director of the California Center for Urban Horticulture (CCUH), Co-Director of the UC Nursery and Floriculture Alliance at UC Davis and past Chair of the Saratoga Horticultural Research Endowment.  He earned his B.S. in Plant Science at UC Riverside, and his M.S. and Ph.D. from UC Davis in Environmental Horticulture and Plant Physiology.  Fujino’s experience includes over 17 years in senior level management with a large wholesale horticultural company.  His expertise includes organizational development, operations improvement, information technology, strategic planning, marketing, research and development, training, fund raising, and other areas.  In 2017, he was inducted into the Green Industry “Hall of Fame” for having a positive impact in the horticulture industry.  His current focus is on the implementation of the SmartLandscape initiative at UC Davis, which demonstrates different landscape projects designed to conserve water and to meet the California’s Model Water Efficient Landscape Ordinance by leveraging current irrigation technologies.

His favorite California native is Ceanothus ‘Ray Hartman”.

Haramrit Gill

Environmental Horticulture Advisor 
UC Cooperative Extension
Tulare, Fresno, Madera and Kings Counties

Haramrit Gill joined UCCE in April 2024 as Environmental Horticulture Advisor for Tulare, Kings, Fresno, and Madera Counties. Hailing from Punjab, India, Haramrit's profound passion for agriculture developed organically. She earned her undergraduate degree in agriculture followed by a master’s degree in Horticulture at Punjab Agricultural University, where her research focused on micropropagation and haploid production in muskmelons.

 In 2018, Haramrit relocated to the USA to pursue a PhD in Horticulture at Texas A&M University. Her early research investigated the impact of nitrogen on spinach root architecture before transitioning to the rose breeding and genetics lab. Here, her doctoral work concentrated on deciphering the genetic underpinnings of flower color transition traits, fragrance, and dwarfing in roses, with a particular focus on the intriguing phenomenon of flower color transformation from yellow to dark pink as blooms matured. Haramrit also contributed to projects aimed at enhancing heat tolerance and disease resistance in roses.

 In her current capacity as an Environmental Horticulture Advisor, Haramrit's responsibilities revolve around identifying landscape plants that are heat-tolerant, disease-resistant, and fire-resistant. She harbors a strong interest in researching California native plants due to their sustainable attributes, which include superior adaptation, biodiversity enhancement, water efficiency, and soil health benefits. Haramrit speaks Punjabi (her native language) and Hindi. Her favorite California native species is Ceanothus (California Lilacs).

Jessie Godfrey

Environmental Horticulture and Water Resource Management Advisor
UC Cooperative Extension
Alameda, Contra Costa, Santa Clara, San Mateo, and San Francisco Counties

Jessie joined UCCE in October 2023. She comes to this position as a tree physiologist, with a PhD in Horticulture and Agronomy from UC Davis. Most of her academic training has centered around quantifying abiotic stress in woody perennials. Nursery-serving postdoctoral research positions with the USDA Forest Service and CAL FIRE focused on greenhouse drought conditioning experiments and digital mapping to triage cone scouting locations, respectively. Jessie is also a former professional gardener, a returned agroforestry extension US Peace Corps Volunteer, an Oakland native, and the mother of two joy machines.

Within broad themes of environmental horticulture and water resource management in the Bay Area, please get in touch about information gaps you want addressed through applied research and/ or extension materials. She will choose among these ideas as she gets her first projects going. If Jessie must name just one favorite California native, today it’s Styrax officinalis var. redivivus.

Grant Johnson

Urban Agriculture Technology Advisor
UC Cooperative Extension
Orange and Los Angeles Counties

Grant Johnson is the Urban Agriculture Technology advisor for Orange and Los Angeles counties providing impartial, research-driven insights to optimize plant production in urban environments. He received a Bachelor’s degree in Biological Sciences from Cal Poly SLO and became a research associate for UCANR working on projects ranging from herbicide efficacy trials, irrigation management, ornamental plant trials, and slow sand filtration water treatment. One decade later, he earned his Master of Science in Horticulture and Agronomy at UC Davis. With a focus on indoor production, such as greenhouses, his diverse clientele includes nurseries, commercial growers, school districts, and community gardens. In his dynamic role, he actively shapes the future of urban agriculture by tackling challenges of how to improve local food production. This involves creative exploration of horticultural topics related to irrigation, plant culture, and agricultural technology innovations that drive the future of farming, ensuring technological advancements that benefit a wide range of urban farming practitioners.

Donald Merhaut

Associate Extension Specialist
UC Riverside

Don Merhaut is a Specialist for the ornamental, floriculture, landscape and nursery industries.  Don has been with UC Cooperative Extension since 2000.

Don was born and raised in Pittsburgh, PA.  He received his Bachelor of Science in Horticulture at Pennsylvania State University.  He did a Master’s of Science in Horticulture at the University of Georgia.  His thesis was on effects of ethylene on shoot and root growth in peaches.   He then went to the University of Florida for his Ph.D. where he worked on nitrogen nutrition of rabbiteye and  southern highbush blueberry.  Afterwards, he did a postdoc with the USDA in Houston, TX working on nitrogen nutrition of rice.  He finally moved west and worked for Monrovia Nursery for two years before going back to academia and taking the position of Extension Specialist at the University of California.

Don’s research and outreach focuses on plant physiology, plant nutrition, fertilizer and media management, and impact of the environment on nursery production, landscapes,and natural ecosystems.

My favorite California native plant, when California was under the territory of the Viceroyalty of Spain in 1821, would be Sophora secundiflora, which is native to the Chihuahuan Desert.  I especially love cultivar ‘Sierra Silver’, which was introduced by Mountain States Nursery as a grafted selection in 2012.  Second place would be Yucca brevifolia, called the humwichawa by the Indigenous Cahuilla.  (It would be first, but I can’t grow in Riverside, CA.).  Number three would be Larrea tridentata, the creosote bush.

I am fluent in three languages - English, Pittsburghese (like Emma), and Southern.

Lorence (Loren) Oki

Specialist in CE Emeritus
Department of Plant Sciences
UC Davis

Loren is a Specialist in Cooperative Extension Emeritus having “retired” in 2023 after more than 20 years at UC Davis.  His research and extension program focused on water issues in urban landscapes, greenhouses, and nurseries and studied runoff from residential sources, biological water treatment methods, characterizing nursery runoff, and assessing responses of plants to deficit irrigation and providing irrigation recommendations to those plants. 

Loren continues to lecture to the landscape and nursery industry, regulatory agencies, pest management professionals, and Master Gardeners on topics including irrigation management, pollution reduction, water treatment, and others.

His B.S. in Ornamental Horticulture is from Cal Poly SLO, M.S. in Plant Sciences from UC Riverside, and Ph.D. in Ecology from UC Davis. He worked at Oki Nursery, founded by his grandfather, prior to coming to UC Davis.  He has served on numerous trade, regulatory, and academic organizations on committees and other groups.

Ana M. Pastrana

Plant Pathology Advisor
UC Cooperative Extension
Imperial, Riverside, and San Diego Counties

Ana is the Plant Pathology Advisor for Imperial, Riverside, and San Diego counties. In this position, Ana addresses local plant disease concerns in commercial vegetable, field, seed, and tree crops; and in the horticultural, nursery, and greenhouse industries through applied research and extension. Her expertise lies in plant pathology, and she joined UC ANR in January 2024. Before this role, Ana served as a Research Scientist in Spain and Canada, conducting research, teaching, and extension. She earned her Ph.D. in 2015 from IFAPA, Spain, and subsequently advanced her research during post-doctoral studies at the University of California, Davis. With over a decade of experience, Ana's work has focused on investigating the etiology, epidemiology, and management of plant diseases within agricultural ecosystems. Ana also speaks Spanish, her native language. Her favorite California native species is the arroyo lupine (Lupinus succulentus).

Bruno J.L. Pitton

Environmental Horticulture Advisor 
UC Cooperative Extension
Placer and Nevada Counties

Bruno is the Environmental Horticulture Advisor for Placer and Nevada Counties. Bruno works with all segments of the Green Industry: nursery, greenhouse, professional landscapers, horticultural consultants, and Master Gardeners. Bruno received a BS in Environmental Horticulture and a MS and PhD in Horticulture and Agronomy from UC Davis. Prior to being an Advisor, Bruno worked in the Department of Plant Sciences at UC Davis and conducted research on water capturing and recycling and nitrogen management in nursery production. Bruno has been investigating controlled-release fertilizer release rates, optimizing nutrient application for vegetable transplant production, and developed a free irrigation best management practice training for nursery and greenhouse growers. In addition to his academic experience, Bruno managed integrated pest management, irrigation and fertilizer programs in greenhouses at UC Davis. His favorite California native plants are in the genus Calochortus (Mariposa lilies, globe lilies) due to the great diversity and unique floral morphology within California.

Chris Shogren

Environmental Horticulture Advisor
UC Cooperative Extension
Los Angeles County

Dr. Chris Shogren serves the County of Los Angeles as an Environmental Horticulture Advisor for the University of California Cooperative Extension. Dr. Shogren grew up in the horticulture industry, working at his parents’ wholesale nursery in Southern California. His undergraduate studies focused on plant production at the California Polytechnic University, San Luis Obispo, where he received degrees in Environmental Horticulture and Agricultural Business. He then went on to receive his PhD in Entomology from the University of California, Riverside, where his research focused on integrated pest management of invasive thrips. Dr. Shogren’s current research focuses on management of insects, diseases and weeds and increasing water use efficiencies in nurseries, landscapes, and municipalities. Chris’s favorite California native is the majestic giant sequoia (Sequoiadendron giganteum).

Joanna Solins

Environmental Horticulture Advisor
UC Cooperative Extension
Sacramento, Solano, and Yolo Counties

Joanna Solins is the environmental horticulture advisor for Sacramento, Solano, and Yolo Counties. In this position, she provides research and outreach to support landscape, horticulture, and arboriculture professionals, as well as institutions and regulators concerned with urban forests and landscaping. Her program has an emphasis on the use of plants and landscaping to mitigate climate change impacts in urban environments, and her current work focuses on climate-ready urban forests and water-efficient landscaping. Originally from Massachusetts, Joanna has enjoyed living in California for over 15 years now. She earned her bachelor’s degree from Vassar College in environmental studies and started her career in education and communications before attending UC Davis for her MA in geography and PhD in ecology. Her favorite California native species is the valley oak (Quercus lobata), which was generous in providing data for her dissertation research.

Gerry Spinelli

Production Horticulture Advisor
Cooperative Extension
San Diego County

 Gerry is the production horticulture advisor for San Diego County. Through this position, Gerry supports the nursery, floriculture, and controlled environment industries through applied research and extension. His expertise is in irrigation and nutrient management. Gerry was born in Florence, Italy. He got his Bachelor's degree from the University of Florence in Agriculture Science and Technology and a MS in Tropical Agriculture. He has a MS in International Agricultural Development and a PhD in Horticulture and Agronomy, from UC Davis as well as twenty years of experience in irrigation, extension and applied research. Gerry speaks French and Spanish in addition to his native Italian. He has forgotten most of his Lebanese Arabic. Gerry’s favorite California native species is the toyon (Heteromeles arbutifolia). Did it really give its name to Hollywood?

Emma Volk

Production Horticulture Advisor
UC Cooperative Extension
Ventura and Santa Barbara Counties

Emma Volk is the production horticulture advisor for Ventura and Santa Barbara Counties. Through this position, Emma supports the nursery, floriculture, and controlled environment industries through applied research and public outreach. Her current work focuses on nutrient management, steam-based disinfestation practices, and cultural pest management. 

Emma was born and raised in Pittsburgh, PA. She got her Bachelor's degree at Cornell University, studying International Agriculture and Rural Development. She has a MS in Horticultural Science from North Carolina State University, as well as five years of experience in extension and applied research. She is happy to now reside on the west coast, where she gets to explore a whole new world of plants. Emma’s favorite California native species is the Giant Coreopsis (Coreopsis gigantea).

Dean Watson

AIR Research Associate 
Department of Plant Pathology
UC Davis, Del Castillo Lab

Dean is a research associate in the Del Castillo Lab of the Department of Plant Pathology at UC Davis. He earned his bachelor’s degree in biological sciences from UC Davis, then became a research associate in the plant pathology department studying fungal pathology in agricultural systems.

Dean now provides research and support for the Accreditation to Improve Restoration (AIR) program, a new program with the goal of protecting California native habitat restoration sites by implementing plant production best management practices for the exclusion of Phytophthora in the nursery (https://airnursery.ucdavis.edu/). In this role, Dean works directly with California restoration nursery growers for successful BMP implementation and provides outreach to spread awareness about Phytophthora prevention and testing methods. He also provides media communications assistance for the UCNFA newsletter. 

His favorite California native plant species is the Valley Oak, Quercus lobata, for its striking branching structure and dramatic stature in California’s rolling oak savannas.