Principal Investigators

Dr. Caio Brunharo. Caio is an assistant professor in the Department of Crop and Soil Science at Oregon State University. Dr. Brunharo obtained his PhD and postdoctoral training from the University of California at Davis, MSc in Crop Science from University of Sao Paulo, and BS in Agricultural Engineering from the University of Sao Paulo. His research integrates physiological, biochemical, molecular, and analytical approaches to understand the evolutionary basis of herbicide resistance, and how integrated pest management strategies may be used to prevent crop losses due to weed interference. Dr. Brunharo teaches undergraduate and graduate level courses in weed science and herbicide physiology.



Dr. Andrew Hulting. Andy is a professor in the Department of Crop and Soil Science at OSU. Responsibilities include state-wide weed management support for agronomic crops for farmers, OSU Regional Extension Faculty, and the diverse agricultural industry throughout Oregon. Specific emphasis is on the development of environmentally and economically sustainable integrated weed management systems. Research interests include the biology and ecology of problematic agricultural weed species and invasive weed species management where agricultural/non-agricultural land uses overlap.



Dr. Carol Mallory-Smith. Carol is an emeritus faculty member in the Crop and Soil Science Department. She has served the Oregon industry for the past 25 years. Her program focuses on understanding gene flow between weed and crops, herbicide resistant weeds, and identification of farming practices to reduce weed interference.

Faculty Research Assistants

Kyle Roerig. Kyle is a Senior Faculty Research Assistant and has been in the Weeds program since 2011. Kyle conducts research trials throughout Oregon, with focus on mint, clover, and wheat, and actively participates in the grass seed research, as well as postdoctoral and graduate student’s projects. Kyle regularly contributes to the Extension component of our program.

Postdoctoral Scholars

Dr. Seth Abugho. Seth’s project aims to develop a solid understanding of the management of grass seed crop residue as an integrated weed management tool to reduce weed seed/volunteer crop seed contamination in commercial cool-season grass seed lots.  The long-term goal of his project is to reduce the herbicide selection pressure on populations of annual bluegrass, roughstalk bluegrass, Italian ryegrass, volunteer tall fescue and perennial ryegrass through use of more effective, efficient, economical and sustainable weed management practice. Part of Seth’s investigation includes weed seed germination dynamics and weed seedbank changes over time as affected by grass seed crop residue. Seth likes to learn new languages and his hobbies include playing the guitar, hiking and traveling.

Dr. Lucas Riboldi. Lucas’ project aims to unravel herbicides metabolism in resistant plants of Italian ryegrass, common lambsquarters and tansy ragwort, using plant physiology and biochemistry techniques, but also modern techniques like genetic sequencing, gene expression, and metabolite analysis using mass spectrometry. Many herbicides are currently being tested for Lucas’ research, including auxinic herbicides (2,4-D, dicamba, tryclopyr and fluroxypyr) for tansy ragwort, bentazon for several commom lambsquarters populations, flufenacet for several Italian ryegrass populations, and glufosinate for Italian ryegrass. Lucas’ work also include herbicide metabolism in enhanced CO2 atmosphere. Lucas likes to learn new languages and his hobbies is hiking, cooking and traveling.

Dr. Andreia Suzukawa. Originally I’m from Brazil, where I grew up and have lived for the most part of my life in a school-farm, where my father was a teacher. In 2009, I got my BS degree in Agronomy from the State University of Maringa. I received my MS in Seed Science and PhD degree in Seed/Weed Science in 2015 and 2019, respectively, from the same university. My doctoral thesis was on biochemical markers to differentiate tolerance of soybean varieties to chlorimuron-ethyl, diclosulam and to sulfentrazone. Currently, I’m a postdoctoral scholar supervised by Drs. Brunharo and Hulting. My project is focused on developing a herbicide bioassay to measure the magnitude of herbicide resistance in annual ryegrass. In addition, I am working on side projects to understand the genetic variability of annual ryegrass weed, such as vernalization genes and investigation of genotype-phenotype association with morphological characteristics.

Graduate Students

Roque De Carvalho. Roque is a visiting scholar working towards his PhD at Sao Paulo State University. Roque is studying a cover crop species – Mucuna aterrina – and its allelopathic effects on weed species. He is particularly interested in one of the compounds produced by this species, L-Dopa, and is trying to understand its effects on Italian ryegrass. Roque has worked in several areas of weed science, including applied research, analytical chemistry, and integrated weed managament. Roque is also working on side projects, while a visiting scholar in our program, including a project in collaboration with Dr. Fernando Adegas to look at multiple herbicide resistant Amaranthus hybridus to ALS and EPSPS inhibitors.

Undergraduate Students

Chandra Maki. I am currently a senior at Oregon State University getting my Bachelor’s degree in Crop and Soil Science with an option in plant breeding & genetics and agronomy. I have been working in the weeds and agronomy department for Oregon State since April of 2018 starting as an undergraduate worker. Since then I have helped over half a dozen Master, Doctorial, and Post Doctorial students with their projects and research. I have also worked on my own research with the guidance of other professors in the department on ALS resistance in Downy Brome and other research in herbicide resistance in weeds. I have also worked in molecular testing in Downy Brome by sequencing DNA of resistance populations and mapping cross resistance and target-site resistance in suspected herbicide resistant populations. My hobbies are taking care of and propagating house plants, and when I am back home taking care of and raising my family’s herd of cattle and lambs.

Nixxon Montgomery. I’m a senior at Oregon State University who has been working in the weed science and agronomy department since June 2018.  During my time here I have aided more than half a dozen masters and PhD students on their projects and have helped with general upkeep of the lab.  More specifically I have done manual labor out in the field helping lay the foundation for a large solarization project, and have on numerous occasions collected large samples of biomass.   I have also cleaned large quantities of seed that has later been used for speed germination tests and transplanting in the greenhouse. This job has given me the opportunity to greatly expand my knowledge of weed management and the rye grass industry in Oregon.  In my free time I like to study social studies by listening to various audiobooks and podcasts on foreign policy, history, and politics.  I also enjoy playing strategy games and am a big board game enthusiast. 

Adriana Perez. Adriana is an undergraduate student working towards her degree in Crop and Soil Science. She first started in our group as part of the STEM Leaders program, and decided to continue working in our groups after the termination of her tenure.


Dr. Seji Jang. Seji visited our group for a year to work with allelopathic effect of wheat straw on Italian ryegrass. She was also involved in several other projects in the Weeds group, as downy brome resistance to ALS inhibitors and rattail fescue seed biology. She is currently a postdoctoral scholar at Sunchon National University in South Korea.

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