AR Weed Science

The Southern W**d Science Society Student Contest occurred on August 8th in Newport, Arkansas. Our W**d Science program brought two graduate teams and one undergraduate individual to compete.

Each student was required to perform individual written calibration tests, w**d identification, unknown herbicide identification, and farmer problem diagnosis. The team was also scored in sprayer calibration.

The eight competing students were coached by Drs. Jason Norsworthy and Nilda Burgos. The University of Arkansas team 1 consisted of Noah, Chandler, Cade Halbrook, Rhet Baxley, and Cory Ketchum who took home first place overall. The University of Arkansas team 2 consisted of Aidan Ross, Diego Rodriguez, and Juan Velasquez who took home second place overall and first in team calibration. Haydon Houser was awarded first place overall individual undergraduate.

The group of eight University of Arkansas graduate students and one undergraduate took home multiple individual honors. Noah Chandler won second place overall, Cade Halbrook won third place overall. Aidan Ross won both fifth place overall and first place in written calibration. Haydon Houser won first place undergraduate overall, first place in undergraduate herbicide symptomology, and first place in written calibration.

Join us in welcoming our new M.S. student, Carras Callihan!

Carras graduated from the University of Colorado Boulder in May 2025 with a Bachelor of Arts in Environmental Studies. Carras is originally from Colorado Springs, Colorado. During her undergrad, she was a Public Policy Intern for Colorado Farm Bureau and a Technical Service Intern for BASF in 2024 on the Western Plains.

Carras’ thesis will focus on the tolerance of rice cultivars to HPPD herbicides and w**d control.

Join us in welcoming our new M.S. student, Haeden Barber!

Haeden graduated from the University of Arkansas in May 2025 with a Bachelor’s degree in Crop, Soil, and Environmental Science. Haeden worked as a Crop Scout during his undergrad in 2023 and 2024 in Marianna, Arkansas. Originally, Haeden is from Austin, Arkansas.

Haeden’s thesis will focus on the impact of short versus full corn stature and density on canopy formation.

Join us in welcoming our new M.S. student, Haydon Houser!

Haydon graduated with a Bachelor’s of Science in Agronomy from Purdue University in May of 2025. He is originally from New Carlisle, Indiana. During his undergrad Haydon worked for Advanced Agrylitics as a Crop Scout Intern and BASF as a Field Biology Intern. Haydon’s passion for W**d Science came from an early age working for local farmers in Indiana where he saw many issues that growers had in their everlasting fight to control w**ds. Haydon’s thesis will focus on rice.

On April 21st, Tristen Avent successfully defended his Ph.D. dissertation titled: “Utility of John Deere’s See & Spray Ultimate in Southern U.S. Row Crops” under the advisement of Dr. Jason Norsworthy. Tristen’s committee was comprised of Drs. Lawton Nalley, Gerson Drescher, Tommy Butts, and Alan Vazquez.

Tristen received a B.S. in Agriculture from the University of Tennessee-Martin and a M.S. at the University of Arkansas studying W**d Science. During his studies, Tristen published 7 peer-reviewed manuscripts as first author, 9 research series articles, and has presented 35 abstracts at professional conferences. He is also building two fact sheets surrounding the See & Spray technology for Arkansas producers. Tristen also received the Arkansas Soybean Promotion Board fellowship, the Ron and Alice Talbert Endowed W**d Science Scholarship, and the Dale Bumpers College Outstanding M.S. and Ph.D. student awards. In the coming weeks, Tristen will start working for UPL-NA as a Technical Service Representative.

Congratulations Dr. Tristen Avent!

Pâmela Carvalho-Moore received the 2025 Outstanding Graduate Student Research Award from the Crop, Soil, and Environmental Sciences Department!

Pâmela Carvalho-Moore is a Ph.D. candidate in W**d Science, born and raised in Rondônia, Brazil. She was influenced by her grandfather’s love for plants and agriculture, which inspired her to pursue a career in this field. Pâmela received a B.S. in Agronomy from the Federal University of Pampa in 2017. During her undergraduate studies, she was awarded a fellowship from the Brazilian government to spend 18 months in the United States studying crop science. She chose the University of Arkansas as her host institution and volunteered as an intern in the W**d Physiology Laboratory under the guidance of Dr. Nilda Roma-Burgos. This opportunity led her to pursue an M.S. degree in Cell and Molecular Biology from the University of Arkansas in 2020 with Dr. Nilda Roma-Burgos as her advisor. In 2021, she began her Ph.D. studies under the advisement of Dr. Jason Norsworthy. Pâmela’s Ph.D. research focuses on the addition of metabolic inhibitors to improve the efficacy of the herbicide glufosinate under varied environmental scenarios, as well as understanding the resistance mechanism of glufosinate-resistant Palmer amaranth from Arkansas. She truly believes that meaningful and well-conducted research is a valuable tool for the future of food production and is excited to continue contributing to this field.

Congratulations Pâmela!

On April 21st, M.S. student Michael Dodde, advised by Dr. Jason K. Norsworthy successfully presented his exit seminar entitled “Atrazine mitigation through See & Spray technology”.

Aidan D. Ross is the recipient of the 2025 Tri-Societies National Student Recognition Award!

Aidan was born in Little Rock, AR and raised in Texarkana, TX, receiving his B.S. in Crop Science with a minor in Crop Biotechnology from the University of Arkansas in December of 2024. Throughout his time as an undergraduate, Aidan spent his summers as the Senior Counselor of the Pacer bunkhouse at Brookhill Ranch Summer Camp, where he developed his leadership skills and love for the outdoors. During the school year, he has worked with the Soybean Breeding Program, Fruit Breeding Program, and the W**d Science Program in which he is now an M.S. student under the advisement of Dr. Jason K. Norsworthy. His M.S. research focuses on identifying control options and investigating reports of herbicide resistance for white margin sedge, a newly problematic w**d of Arkansas rice.



Congratulations Aidan!

On April 15th, Maria Souza successfully defended her M.S. thesis titled “Evaluation of Fluridone in Rice.” Besides her major advisor, Dr. Jason K. Norsworthy, Maria’s thesis had valuable input from committee members Drs. Samuel Fernandes, Tommy Butts, and Trenton Roberts.

Maria, from Minas Gerais, Brazil, received her B.S. degree from Federal University of Lavras prior to starting her M.S. During her academic journey, Maria has authored or coauthored 6 peer-reviewed papers published in prestigious journals, 10 extension or technical reports, and 46 abstracts from scientific presentations at national and international conferences. She has presented research at the Arkansas Crop Protection Association, Beltwide Cotton Conference, Brazilian W**d Science Congress, Rice Technical Working Group, Southern W**d Science Society, and W**d Science Society of America. She was also a member of the first- and second-place teams at the Southern W**d Science Society W**d Contest in 2024 and 2023, respectively, and placed second in 2024 and third in 2023 in the graduate individual category. Additionally, Maria was recognized as the Crop, Soil, and Environmental Science Outstanding M.S. Student.

Maria will begin pursuing her PhD in W**d Science at Purdue University under the advisement of Dr. Tommy Butts.

Congratulations M.S. Maria Souza!

On April 14th, M.S. Maria Souza, advised by Dr. Jason K. Norsworthy successfully presented her exit seminar entitled “Rice tolerance to fluridone application timing and mixtures with commonly used herbicides”.