Postgraduate Research Associates

Sulley Ben-Mahmoud, Ph.D.

Picture of Sulley in the field.

About Dr. Ben-Mahmoud

Dr. Ben-Mahmoud received his Ph.D. in Entomology from the University of Florida, Gainesville.

Sulley’s research focuses on Insect-Pathogen-Plant Interactions.

To contact Sulley, email

From Sulley

With a Ph.D. in entomology from the University of Florida, I have engaged my research expertise in the areas of insect physiology, biochemistry, and molecular biology towards the pivotal role of insects as vectors of plant diseases. Notably, I have delved into the dynamics of diseases including tomato spotted wilt virus, vectored by western flower thrips, and citrus greening, transmitted by psyllids. At WSU-IAREC, I am excited to channel my experience toward advancing the comprehension of viral pathogen transmission by grape mealybugs. By leveraging my insights into the interactions between insects, plant pathogens and plant hosts, I aim to contribute significantly to the quest for clarity in grape mealybug-mediated disease dynamics.

Poonam Chaudhary, Ph.D.

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About Dr. Chaudhary

Dr. Chaudhary received her Ph.D. in Botany from Guru Nanak Dev University, Amritsar, Punjab, India.

Poonam’s research focuses on Plant Virology.

To contact Poonam, email

From Poonam

I’m from Punjab, an Indian state that is renowned for its agriculture. I have always been intrigued by viral infections that impact various crops. I, therefore, completed my doctoral work on indexing of viral diseases of tomato crop in North-western region of India as well as the contribution of weeds to the spread of viral infections. I joined IAREC to increase my expertise of grapevine diseases under the guidance of Dr. Naidu A. Rayapati. To promote Washington’s clean plant programs, certified nurseries must maintain healthy grapevines. In order to achieve this goal, the Prosser IAREC Grape Virology Program has been working with nursery managers and the Plant Services Program of the Washington State Department of Agriculture to maintain virus-tested mother vines in registered blocks.

Ricardo Delgado Santander, Ph.D.

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About Dr. Delgado Santander

Dr. Delgado Santander received his Ph.D. in the Biomedicine and Biotechnology Progamme at the Universitat de València in Spain.

His research focuses on antibiotic resistance in Erwinia amylovora (fire blight).

To contact Ricardo, email

From Ricardo

My research experience is centered in the field of plant-pathogen interactions, with a particular focus on the fire blight pathogen Erwinia amylovora. With a PhD from Universitat de Valencia, I characterized the effects of starvation on the survival responses and virulence mechanisms of E. amylovora. I studied multiple aspects of E. amylovora’s life cycle, including physiological responses to nutrient depletion, the involvement of the sigma factor RpoS and catalases in these processes, and their roles during plant-pathogen interactions. I also investigated the bacterium’s potential for root colonization, induction of the viable but nonculturable response by stressing agents, recovery of cultivability through passage in susceptible hosts, and E. amylovora transmission by the medfly Ceratitis capitata. During my four years as a Postdoctoral Associate at Cornell University, I devoted my efforts to developing and optimizing a viability digital PCR protocol for selective quantification of viable E. amylovora cells. I employed this method to assess pathogen survival and population dynamics in fire blight cankers. I delved into the complexities of copper resistance in the fire blight pathogen through RNA-seq analysis, conducted fire blight and blister spot diagnostics, contributed to the development of a specific PCR for identifying the parasitic wasp Trissolcus japonicus (used for brown marmorated stink bug biocontrol), and evaluated the resistance of different apple cultivars to Colletotrichum species present in New York state. As a Research Associate at WSU-IAREC, my current objectives involve identifying and analyzing E. amylovora antibiotic resistance mechanisms. I have optimized a method for identifying potential biocontrol agents against E. amylovora. I also lead a two-year project funded by the WTFRC studying new compounds to control shoot blight. Since 2009, I have mentored over 15 students, engaged in teaching, reviewed scientific papers for various journals, presented at conferences, and contributed to grant writing.

R. Geraldine Diverres Naranjo, Ph.D

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About Dr. Diverres Naranjo

Dr. Diverres Naranjo received her Ph.D. in Horticulture from Washington State University.

Her research focus is grapevine physiology and water relations.

To contact Geraldine, email

From Geraldine

I grew up in the Canary Islands, Spain. My hobbies are scuba diving, sailing and rope jumping. I decided to study viticulture because I am passionate about how different human populations adapt their horticultural practices to the environment. The different wine producing regions around the globe showcase this beautiful dance in which the landscape and the vineyards shape each other.

I would love to speak Russian, Portuguese and Japanese.

Sridhar Jarugula, Ph.D.

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About Dr. Jarugula

Dr. Sridhar Jarugula received his Ph.D. in the Plant Pathology.

His research focuses on Biology and Epidemiology of Plant Viral Diseases.

To contact Sridhar, email

From Sridhar

My research focuses on several aspects of plant virology research including basic biology, epidemiology and diagnostics. Plant virus diseases I have worked on includes those that impact economically important horticultural, vegetable and food crops such as grape vines, beans, and wheat. My research interests include: virus characterization, virus-based vector systems, and plant-virus-vector interactions. I am particularly interested in utilizing scientific advances to develop and implement sustainable disease management strategies.

Amit Kesharwani, Ph.D.

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About Dr. Kesharwani

Dr. Amit Kumar Kesharwani received his Ph.D. in Biotechnology with collaboration of Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, India and Amity Institute of Biotechnology, Amity University, Noida, India.

His research focuses on plant-pathogen interaction (Fire blight and X-diseases of orchards), antimicrobial resistance in phytopathogens, and CRISPR/CAS based diagnosis of phytopathogens.

To contact Amit, email

From Amit

I was born in the capital of India, Delhi. I completed my Doctorate in Biotechnology on “Characterization and functional analysis of avr gene(s) of Indian isolates of Xanthomonas campestris pv. campestris causing black rot disease in cauliflower” with collaboration of Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, India and Amity Institute of Biotechnology, Amity University, Noida, India. I have experience with various Molecular and Microbial techniques, Plant-microbe interaction (biotic stress), mutagenesis in bacteria, RNA silencing in model plants, plant abiotic stresses, antimicrobial activity of drugs and nano-particles on bacterial growth, transgenics plant development, pathogenicity analysis on vegetable crops i.e., Brassica species and, tomato, and functional validation of Type-III effectors in Xanthomonas. Apart from research, I am a recipient of the ‘DST-Young Scientist’ International Travel grant from the Science and Engineering Research Board, Govt. of India and University of Florida, USA to attend the 7th Xanthomonas Genomics conference at Clearwater, Florida, USA held on June 2022. Besides, I am contributing with my research expertise and skills to serve in prestigious academic journals and play a role in the Editorial Board as a Review Editor (Frontiers in Virology) and Reviewer (BMC Microbiology, Scientific Reports).

I joined the Department of Plant Pathology, Irrigated Agriculture Research and Extension Center, Washington State University (IAREC-WSU), Prosser as a Postdoctoral Research Associate in July 2023 with Dr. Youfu “Frank” Zhao. I am a member of the Diversity, Equity, and Inclusion (DEI) committee. My research focuses on Phytopathological diseases such as Fire blight and X-diseases of orchards like Apple, cherry, and Pear caused by Gram-negative Erwinia and phytoplasma, antimicrobial resistance in phytopathogens, CRISPR/CAS-based diagnosis of X-disease phytoplasma.

Salik Ram Khanal, Ph.D.

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About Dr. Khanal

Dr. Khanal received his Ph.D. from Universidade de Tras-os-Montes e Alto Douro, Vila Real Portugal in Computer vision and specialized in Computer Vision.

His research focuses on computer vision, machine learning, deep learning, machine vision, and robotics.

To contact Salik, email

From Salik

Hello, I am Salik Ram Khanal originally from Nepal, presently engaged as a postdoctoral researcher at the Washington State University-Irrigated Agriculture Research and Extension Center (IAREC) located in Prosser, Washington. My academic background in Computer Vision has seamlessly guided me towards the captivating realm of applying machine vision and robotics in the field of agriculture.

Throughout my tenure at IAREC, my overarching goal revolves around making significant contributions to the progression of sustainable agricultural practices through the integration of cutting-edge technology, particularly focusing on machine vision and robotic field operations. By harnessing the potential of machine vision and robotics, I am dedicated to redefining the paradigm of agricultural field operations.

Central to my research endeavors is the development of inventive solutions that seamlessly amalgamate machine vision algorithms and robotics systems within agricultural landscapes. Through the design and implementation of intelligent machinery capable of perceiving, analyzing, and adapting to outdoor environments, my aspirations encompass the notable enhancement of efficiency, precision, and sustainability within crop cultivation. My primary objective lies in the real-time automation of diverse field operations, ranging from pruning to thinning and pollination of tree fruits, thereby bridging the nexus between technology and agriculture and making substantial contributions to global labor management.

Beyond my scholarly pursuits, I find myself immersed in a plethora of hobbies. Exploring diverse terrains and capturing the essence of nature through photography serves as my conduit to connect with the world’s various landscapes. Sharing these captivating experiences and interests with others, while also reciprocating their passions, brings me immense joy. Moreover, my profound interest in culinary endeavors beckons me to the kitchen, where I experiment with new recipes inspired by the rich tapestry of cuisines from around the world.

In essence, my journey at IAREC is underpinned by an unwavering commitment to pushing the frontiers of technological innovation within the realm of agriculture. By weaving together my fervor for machine vision, robotics, and sustainable practices, my aspirations are firmly rooted in leaving an indelible imprint on the future of farming and environmental conservation.

Safal Kshetri, Ph.D.

Picture of Safal during a tour.

About Dr. Kshetri

Dr. Kshetri received his PhD from Iowa State University in Agriculture and Biosystems Engineering.

His research focuses on robotics, controls, computer vision, machine learning in agriculture.

To contact Safal, email

From Safal

Originally from Nepal, I am currently a researcher in Agrobotics lab at IAREC, where I focus on finding optimal technological solutions to address complex challenges in agriculture. Engineering is fun! Outside of research, I enjoy playing and watching soccer.

Amber Loptien, M.Sc.

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About Ms. Loptien, M.Sc.

Amber received her master’s degree from Washington State University in Plant Pathology.

Their research focuses on interactions between lentils and Fusarium oxysporum.

To contact Amber, email

From Amber

I was born and raised in Reno, Nevada. I received my bachelor’s degree in biochemistry and molecular biology from the University of Nevada, Reno. I joined IAREC in 2020 through my plant pathology masters program where I studied grapevine viruses, specifically Tobacco ringspot virus (TRSV) and its metabolic effects on grapevines. After graduating in 2023, I was offered a job as an associate researcher at IAREC under Dr. Lyndon Porter studying pulse crops, mainly lentils and peas, and their interactions with Fusarium.

Makonya Givemore Munashe, Ph.D.

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About Dr. Makonya

Munashe received his Ph.D. from University of Cape Town, South Africa in Biological Science (Plant Ecophysiology).

His research focuses on physiology and genetic mechanisms contributing to red raspberry’s heat tolerance.

To contact Munashe, email

From Munashe

I was born and grew up in Masvingo, a province on the south-eastern part Zimbabwe. I have a B.Sc. in Horticultural Science and an M.S.c in Crop Science, both from the Midlands State University in Zimbabwe. I then proceeded to join the Department of Biological Science at the University of Cape Town (UCT), South Africa in 2016 as a Ph.D. candidate. Prior to joining the labs of Drs. DeVetter and Peters at WSU in January 2023, I was a postdoctoral fellow in the Plant Stress Lab at UCT working on Molecular and Physiological approaches to drought tolerance in Bambara groundnut (Vigna subterranea (L.) Verdc.). Currently I examine the physiological and genetic mechanisms that contribute to red raspberry’s heat tolerance across cultivars and advanced selections, as well as evaluating the impacts and cost-benefits of heat mitigation technologies across several cultivars and promising selections.

Alvaro Soler-Garzón, M.Sc.

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About Mr. Soler-Garzón, M.Sc.

Alvaro received his master’s degree from the National University of Colombia in Agricultural Sciences.

His research focuses on molecular markers and gene identification.

To contact Alvaro, email

From Alvaro

I am from Colombia, with a Master in Agricultural Sciences from the National University of Colombia, and a BSc in Biology from the University of Tolima. A significant part of my professional career includes my tenure as a Research Assistant at the International Center of Tropical Agriculture (CIAT) in Palmira, Colombia. My time at CIAT laid a strong foundation for my expertise in molecular breeding technologies and provided valuable insights into the complexities of improving common beans.

In my current position as a Research Associate at the Irrigated Agriculture Research and Extension Center (IAREC) at Washington State University (WSU), I have made substantial contributions to the development of molecular markers and gene identification related to resistance/tolerance for both abiotic and biotic stresses. These efforts are part of projects collaborated on with the Grain Legume Research Unit – USDA-ARS.

Charles Obiero, Ph.D.

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About Dr. Obiero

Dr. Charles Obiero received his Ph.D. from Murdoch University, Perth, Australia, in Biological Sciences (Plant Physiology).

His research focuses on how abiotic factors such as drought, temperature and plant nutrition and cropping practices such as cropping systems influence whole plant carbon production and its partitioning to the various plants parts and how to agronomically manage them.

To contact Charles, email

From Charles

I am from Kenya and am currently a postdoc with Markus Keller at Washington State University investigating water stress physiology in winegrapes. Before that, I explored the impact of episodes of high temperatures on potato physiology and how biofuel cropping systems altered food crop production in corn and dry beans. My research goal is to find practical agronomic solutions to abiotic stresses and cropping practice challenges. Therefore, I hope findings from my current work will help the Washington State Winegrape Growers and the Wine Industry make necessary adjustments (if any) now and for future winegrape production. I love landscape photography, watching birds, and taking evening walks under beautiful sunsets.

Nataliya Shcherbatyuk, Ph.D.

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About Dr. Shcherbatyuk

Dr. Shcherbatyuk received her Ph.D. in Horticulture from Washington State University.

Her research focuses on Grapevine Nutrition.

To contact Nataliya, email

From Nataliya

Currently, I am a postdoctoral researcher in the lab of Dr. Markus Keller. My primary focus revolves around the optimization of sampling protocols to facilitate efficient nutrient management within vineyards. My work centers on the re-evaluation of existing sampling procedures for the analysis of grapevine tissue nutrients. Furthermore, I am particularly drawn to the topic of nutrient recycling, with a specific emphasis on potassium. In addition to my primary role, I also serve as project manager for High-Resolution Vineyard Nutrient Management. In this capacity, I collaborate closely with the project director to ensure the team’s adherence to grant-related obligations and timelines. I am involved in outreach efforts, as well as the coordination of project team meetings. My professional background is rooted in viticulture research, and I hold a keen interest in Outreach and Extension activities.

I am very passionate about plants overall as well as a plant-based lifestyle, which you can learn more about at

Mohamed Abdou Youssef

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About Mr. Youssef

Mohamed currently pursuing my Ph.D. studies at Ain Shams University in Cairo, Egypt.

His research centers on advancing irrigation management through innovative methods, including remote sensing, geographic information systems (GIS), as well as machine learning, and deep learning techniques.

To contact Mohamed, email

From Mohamed

Hello, I am Mohamed Youssef, from Qena, Egypt. I work as a teaching assistant at the Agricultural Engineering Department, Faculty of Agriculture, Ain Shams University. Presently, I am a visiting scholar at the Irrigated Agriculture Research and Extension Center (IAREC) at Washington State University (WSU). Collaborating closely with Professor Troy Peters, I am engaged in the ‘SMART Irrigation for Maximizing Water Use Efficiency’ project. My primary focus lies in establishing cost-effective SMART irrigation systems aimed at conserving water, particularly in regions grappling with water scarcity. I have a keen interest in reading books centered on various lifestyles. Additionally, I thoroughly enjoy both participating in and watching football matches.