Fernando Oreja

Assistant Professor in Weed Science
Plant and Environmental Sciences Department

Office:
Phone: 919-591-1543

Email: foreja@clemson.edu

Educational Background

Dr. Agricultural Sciences
Universidad de Buenos Aires 2014

Eng. Agronomy
Universidad de Buenos Aires 2005

Courses Taught

Weed Management

Profile

Fernando H. Oreja is an Assistant Professor in the Department of Plant and Environmental Sciences at Clemson University, specializing in Weed Ecology. His research focuses on weed population dynamics, herbicide resistance, and integrated weed management strategies in diverse cropping systems. With a background in agronomy and agricultural sciences, Dr. Oreja has conducted extensive research on seed dormancy, weed competition, and predictive modeling of weed emergence. He has held academic and research positions at the University of Buenos Aires, Oregon State University, and North Carolina State University. Dr. Oreja actively collaborates with industry and extension programs to develop science-based solutions for growers and is involved in national and international weed science organizations.

Research Interests

My research focuses on weed ecology and management, integrating ecological principles with agronomic practices to develop sustainable strategies for weed control. A key aspect of my work is understanding weed population dynamics, seed dormancy, and emergence modeling, with an emphasis on the role of environmental conditions, crop management, and seedbank ecology in shaping weed communities. I am currently leading projects on crop rotation intensification and its effects on weed community composition, seedbank dynamics, and herbicide resistance, aiming to develop long-term management strategies that reduce herbicide dependency while improving soil health and biodiversity. Another major area of my research is the development of real-time weed emergence prediction models, using hydrothermal time modeling to forecast seedling emergence under varying climatic conditions, with applications in precision weed management and decision-support tools for growers. Additionally, I am investigating alternative weed suppression strategies, including the role of diversified cropping systems and cover crops in reducing weed competition and improving overall system resilience. My work also involves applied research on emerging technologies, such as AI-driven smart spraying equipment, to optimize herbicide applications and improve precision weed control. My overarching goal is to translate these research findings into practical, science-based solutions that improve weed control efficiency, minimize environmental impact, and promote more sustainable and resilient agricultural systems.

Extension and Outreach

My extension and outreach activities focus on translating weed science research into practical management strategies for farmers, crop advisors, and agricultural professionals. I actively participate in field days, workshops, and extension meetings, providing science-based recommendations on weed control, herbicide resistance management, and integrated weed management practices. My work includes developing technical bulletins, extension articles, and educational materials that address current weed management challenges, such as herbicide-resistant weeds, seedbank management, and sustainable cropping systems.

Publications

Peer reviewed papers

Oreja, F.H., Mahoney, D.J., Jordan, D.L., Jennings K.M., Vann, M., Leon, R.G. (2025). Crop rotation and herbicide program effects on Palmer amaranth and common ragweed population growth rate. Crop, Forage, & Turfgrass Management 11, e70022. https://doi.org/10.1002/cft2.70022
Oreja F.H., Genna N.G., Gourlie, J., Barroso J. (2025) Russian thistle (Salsola tragus) ecology in wheat cropping systems of the Pacific Northwest. Weed Science, 1-22. https://doi.org/10.1017/wsc.2024.77
Oreja FH, Arthur S, Bolfrey-Arku G, et al. (2024) Weed community differences in row crops with varying input levels in Ghana. Weed Science, 1-13. https://doi.org/10.1017/wsc.2024.51
Oreja F.H., Vera A.C.D., Kruk B.C., Scursoni J.A., de la Fuente E.B. (2024) Survey of major weed problems, management practices and herbicide use in extensive row crops from Argentina. Advances in Weed Science, 42, e020240050.
Oreja F.H., Gonzalez-Andujar J.L., Wuest S.B., Barroso J. (2024). Modelo predictivo de la emergencia de salsola (Salsola tragus) Revista de Ciências Agrárias 47(1):360-364.
Barroso J., Wuest, S.B., Oreja, F.H. (2024) Weed competition below ground: a three-year study. Revista de Ciências Agrárias, 47(1), 292-296.
Oreja F.H., Moreno, N., Gundel, P.E., Vercellino, R.B., Pandolfo, C.E., Presotto, A., Perotti, V., Permingeat, H., Tuesca, D., Scursoni, J.A., Dellaferrera, I., Cortes, E., Yanniccari, M., Vila-Aiub, M. (2024) Herbicide-resistant weeds from dryland agriculture in Argentina. Weed Research 1-18.
Oreja F.H., Genna N.G., Gonzalez-Andujar, J.L., Wuest S.B., Barroso J. (2024) A hydrothermal model to predict Russian thistle (Salsola tragus) seedling emergence in the dryland of the Pacific Northwest (USA). Weed Science 72(1), 108-112.
Leon, R.G., Oreja, F.H., Mirsky, S.B., Reberg-Horton, C. (2023) Addressing biases in replacement series: the importance of reference density selection for interpretation of competition outcomes. Weed Science 1-23. https://doi.org/10.1017/wsc.2023.53
Oreja, F.H., Lyon, D.J., Gourlie, J., Wetzel, H.C., Barroso, J. (2023). Russian thistle (Salsola tragus) post-harvest control and plant dispersal. Weed Technology, 1-21. https://doi.org/10.1017/wet.2023.58
Oreja, F.H., Hare, A.T., Jordan, D.L., Leon, R.G. (2023). Previous crop and herbicide timing application effects on weed population growth rate. Crop, Forage, & Turfgrass Management, e20232. https://doi.org/10.1002/cft2.20232.
Mahoney, D.J., Jordan, D.L., Leon, R.G., Oreja, F.H., Roma-Burgos N. (2023) Maternal Effects on Palmer amaranth Height Following Season-Long Interference in Corn, Cotton, and Soybean. Crop, Forage, & Turfgrass Management e20233. https://doi.org/10.1002/cft2.20233.
Oreja, F.H., Stempels, M., de la Fuente E.B. (2023). Population dynamics of Digitaria sanguinalis and effects on soybean crop under different glyphosate application timings. Grasses 2(1), 12-22. https://doi.org/10.3390/grasses2010002.
Oreja, F.H., Inman, M.D., Jordan, D.L., Vann, M., Jennings K.M., Leon, R.G. (2022). Effect of Cotton Herbicide Programs on Weed Population Trajectories and Frequency of Glyphosate-Resistant Amaranthus palmeri. Weed Science, 1-23. doi:10.1017/wsc.2022.41.
Oreja, F.H., Inman, M.D., Jordan, D.L., Bardhan, D., Leon, R.G. (2022). Modeling weed community diversity based on species population density dynamics and herbicide use intensity. European Journal of Agronomy 138, 126533.
Oreja, F.H., de la Fuente E.B. (2022). Digitaria sanguinalis (L.) Scop maternal effects on seed dormancy under environmental variations imposed by crop canopy. Crop & Pasture Science. https://doi.org/10.1071/CP22052
Oreja, FH, Del Fueyo, PA, de la Fuente EB. (2022). Environmental factors regulating Cenchrus spinifex seed germination. International Journal of Pest Management, 1-8. DOI:10.1080/09670874.2021.2024620
Oreja, FH, de la Fuente, EB, Lenardis, AE. (2021). Crop and stubble effects on seedling emergence of sourgrass, palmer amaranth, wild radish and fleabane. Crop & Pasture Science 72, 458-466. https://doi.org/10.1071/CP20490
Oreja, F.H., Inman, M.D., Jordan, D.L., Leon, R.G. (2021). Population growth rates of weed species in response to herbicide programme intensity and their impact on weed community. Weed Research, 61(6), 509-518. https://doi.org/10.1111/wre.12509
de la Fuente, EB, Suárez, SA, Lenardis, AE, Oreja, FH, Fuentes, MT. (2021). Changes in weed communities in the maize crops of the Rolling Pampa between 1960 and 2019. Agronomía & Ambiente, 41(2).
Oreja, FH, Batlla, D., & Elba, B. (2021). Effect of soybean crop structure on large crabgrass (Digitaria sanguinalis) growth and seed dormancy. Weed Science, 69(3), 372-378. https://doi.org/10.1017/wsc.2021.17
de la Fuente, EB, Oreja, FH, Lenardis, AE, Torcat Fuentes M, Agosti, MB, Barrio, A, Barberis, S, Robredo J, Gil, A, Marzetti, M, Niccia, E. (2021). Intensification of crop rotation affecting weed communities and the use of herbicides in the rolling Pampa. Heliyon 7, e06089. https://doi.org/10.1016/j.heliyon.2021.e06089
Oreja, FH, de la Fuente, EB, Batlla, D. (2020). Digitaria sanguinalis seed dormancy release and seedling emergence are affected by crop canopy and stubble. Weed Research 60, 111-120. https://doi.org/10.1111/wre.12392
Scursoni JA, Duarte Vera, AC, Oreja FH, Kruk BC, de la Fuente, EB. (2019). Crop Weed Management Practices in Argentina. Weed Technology 33, 459-463. https://doi.org/10.1017/wet.2019.26
Oreja, FH, de la Fuente, EB, Batlla, D. (2017). Role of seed environment and covering structures on large crabgrass germination. South African Journal of Botany 111, 170-175. https://doi.org/10.1016/j.sajb.2017.03.017
Oreja, FH, de la Fuente, EB, Fernandez-Duvivier, ME. (2017). Response of Digitaria insularis seed germination to environmental factors. Crop and Pasture Science 68, 45-50. https://doi.org/10.1071/CP16279
Oreja, FH, Morvillo, CM, Torcat-Fuentes, M, de la Fuente, EB. (2015). Current scenario of scientific publications related to weeds in Argentina: Comparison with some countries of America. Revista Agronomía & Ambiente. 35 (29), 131-140.
Oreja, FH, Bastida, F, González-Andújar JL. (2012). Simulation of control strategies for decision-making regarding Digitaria sanguinalis in glyphosate-resistant soybeans. Ciencia e Investigación Agraria 39, 299-308.
Oreja, FH, González-Andújar JL. (2007). Modelling competition between large crabgrass and glyphosate-resistant soybean in Rolling Pampas of Argentina. Communications in Biometry and Crop Science. 2, 62-67.

Book chapters

E.B. de la Fuente, D.F. Wassner, FH. Oreja. 2023. Importance of industrial crops. In: “Production and uses of industrial crops” (Eds. E.B. de la Fuente, R.L. Benech-Arnold, A. Gil, A. Kantolic, M. Lopez Pereira, E. Ploschuck, D.M. Sorlino and D.F. Wassner) Editorial: Facultad de Agronomía, Universidad de Buenos Aires. ISBN 978-987-3738-50-0. Book use in the pre-grad classes at Faculty of Agronomy, University of Buenos Aires.
A. Kantolic, E.B. de la Fuente, FH. Oreja, M. Nico, D. Becheran, P. Gimenez and Y. Correndo. 2023. Soybean. In: “Production and uses of industrial crops” (Eds. E.B. de la Fuente, R.L. Benech-Arnold, A. Gil, A. Kantolic, M. Lopez Pereira, E. Ploschuck, D.M. Sorlino and D.F. Wassner) Editorial: Facultad de Agronomía, Universidad de Buenos Aires. ISBN 978-987-3738-50-0. Book use in the pre-grad classes at Faculty of Agronomy, University of Buenos Aires.
Kruk B., Benech-Arnold R.L., Oreja FH. 2016. Dynamics of the weeding problem. In: “Basis and tools for weed management” (Eds. E.H. Satorre, B.C. Kruk y de la Fuente E.B.) Editorial: Facultad de Agronomía, Universidad de Buenos Aires. ISBN 978-987-3738-09-8. Book use in the pre-grad classes at Faculty of Agronomy, University of Buenos Aires.
de la Fuente, EB, Oreja, FH, Vega, AS, Lo Medico, JM. 2016. Biology and ecology of Digitaria sanguinalis. In: “Weeds and invsive plants of Argentina”. Eds: O. A. Fernández, E. S. Leguizamón y H. Acciaresi. Editorial Universidad Nacional del Sur. ISBN 978-987-655-193-9
de la Fuente, EB, Gil, A, Suárez, SA, Morvillo, CM, Oreja FH. 2011. Interactions between soybean crop and the organisms that accompanying it: Management effects. In: ‘Soybean, scientific research developed at INBA (CONICET/FAUBA) and Faculty of Agronomy, UBA”. Correa OS, de la Fuente EB, Carmona MA, Kantolic AM and Lavado RS. Editorial Facultad de Agronomía, Buenos Aires, Argentina, pp. 143-148.