Mirella Ortiz
PSC
Weed Science | Assistant Professor

Biography
Dr. Ortiz is a weed scientist originally from Brazil. She earned a BS in Agronomy from the University of Sao Paulo in 2015 followed by a MS and PhD from Colorado State University in 2018 and 2022. Dr. Ortiz’s research interest includes weed biology and ecology and herbicide physiology to improve weed management.
Awards
Advisor – 1st place in the student poster contest (Tia Lawrence), 2025
Western Society of Weed Science
Advisor – 2nd place in the student poster contest (Olanrewaju Adeyemi), 2025
Western Society of Weed Science
Presidential Award of Merit, 2022
Western Society of Weed Science
Elena Sanchez Memorial WSWS Outstanding Student Award, 2021
Western Society of Weed Science
Outstanding Graduate Student Award, 2021
Aquatic Plant Management Society
R. Ralph Baker Graduate Student Award for Research Excellence, 2021
Colorado State University
Publications | Abstracts
- Beckley, C., Ortiz, M., Westra, E., Ransom, C., (2025). Evaluating Herbicides for Managing Invasive Annual Grass Infestation in Nevada's Mojave Desert. WSWS *
- Oliveira, F.S, Lawrence, T., Westra, E., Ortiz, M., (2025). Parrotfeather (Myriophyllum aquaticum) Biology and Management Options in Utah. WSWS *
- Adeyemi, O.E, Westra, E., Ransom, C., Creech, J.E, Ortiz, M., (2025). Status of Kochia (Bassia scoparia) Herbicide Resistance in Utah. WSWS *
- Lawrence, T., Adeyemi, O., Oliveira, F.S, Westra, E., Ortiz, M., (2025). Understanding Challenges to Eurasian Watermilfoil (Myriophyllum Spicatum) Control in Bear Lake. WSWS *
- Campos, L.F, Oliveira, F.S, Semensato, L.O, Donadoni, P.I, Ortiz, M., Christoffoleti, P.J, (2024). Carryover of Indaziflam to Soybean and Corn Crops in Sugarcane Reformed Areas. WSSA *
- Carnahan, M.S, Ortiz, M., Ransom, C., Westra, E., Yost, M., Creech, J.E, (2024). Early and Late Season Weed Control in Dormant Alfalfa. CANVAS *
- Lawrence, T.M, Ortiz, M.F, (2024). Herbicide Behavior in Hybrid Milfoil and Hydrilla When Applied in Combination. APMS *
- Oliveira, F.S, Ortiz, M.F, (2024). Intact Herbicide Translocation. APMS *
- Adeyemi, O.E, Westra, E., Ransom, C.V, Ortiz, M.F, (2024). Investigating Herbicide Efficacy and Behavior for Controlling Eurasian Watermilfoil in Bear Lake. APMS *
- Silva, P.V, Mauad, M., Ortiz, M.F, (2024). Educational Strategies for Sustainable Weed Control in Agricultural Systems with Crop Rotation in the State of Mato Grosso Do Sul Under a Climate Change Scenario.. WSWS *
- Beckley, C.J, Fronk, N., Ortiz, M., Westra, E., Ransom, C., (2024). Elongated Mustard Management Update in Utah. WSWS *
- Mathews, M., Maughn, W., Ortiz, M., Westra, E., Ransom, C., (2024). Factors Influencing Plant Response to Indaziflam. WSWS *
- Maughan, W.P, Buell, H.L, Ortiz, M.F, Westra, E.P, Monaco, T., Ransom, C.V, (2024). Long-Term Effects of Indaziflam Applications on a Healthy, Diverse Landscape in Northern Utah. WSWS *
- Salmazo, P.V, Silva, P.V, Cardoso, C., Sanchez, A.C, Medeiros, E.S, Ortiz, M.F, (2024). Pre-plant burndown of Conyza spp. in soybeans using atrazine + mesotrione and the evaluation of changes in leaf structure, weed germination timing, and plant back intervals. WSWS *
- Ortiz, M.F, Nissen, S.J, (2024). Protecting Freshwater Resources in the Arid West: Understanding the Impacts of Aquatic Weeds. WSWS *
- McDonald, M.J, Hettinger, E., Ortiz, M., Westra, E., Monaco, T., Ransom, C., (2024). Seedbank Suppression is Critical for Long-Term Dyers Woad Control: It's a Long Woad. WSWS *
- Adeyemi, O.E, Munaro, F., Salmazo, P.V, Silva, P.V, Westra, E.P, Ortiz, M.F, (2024). The Influence of Rainfall on S-metolachlor Activity Applied to Wheat Residue. WSWS *
- Ortiz, M.F, Nissen, S.J, Gray, C.J, (2022). Intact endothall translocates to the roots of aquatic plants: providing evidence of systemic activity. WSWS *
- Ortiz, M.F, Nissen, S.J, Dayan, F.E, (2022). Intact endothall translocates to the roots of aquatic plants: providing evidence of systemic activity. APMS *
- Ortiz, M.F, Nissen, S.J, (2021). Endothall translocation in Elodea canadensis and Lagarosiphon major. APMS + MAPMS *
- Souza, A.S, Leal, J.F, Ortiz, M., Nissen, S., Gaines, T., Pinho, C.F, (2021). Metabolizacao do herbicida 2,4-D como mecanismo de resistencia em buva. II Weed.Con *
- Ortiz, M.F, Nissen, S.J, Dayan, F.E, (2021). Understanding auxin herbicides for aquatic plant management. WSWS + WAPMS *
- Ortiz, M.F, Dayan, F.E, (2020). Florpyrauxifen-benzyl: A novel auxin herbicide for aquatic plant management. WSSA + WSWS *
- Ortiz, M.F, Figueiredo, M., Nissen, S.J, Dayan, F.E, Wersal, R.M, Ratajczyk, W., (2019). 2,4-D amine and 2,4-D butoxyethyl ester behavior in Eurasian and hybrid watermilfoil. APMS + WAPMS *
- Ortiz, M.F, Figueiredo, M., Nissen, S.J, Dayan, F.E, Wersal, R.M, Ratajczyk, W., (2019). 2,4-D amine and 2,4-D butoxyethyl ester behavior in Eurasian and hybrid watermilfoil. WSSA *
- Soufia, G.P, Ortiz, M.F, Nissen, S.J, (2019). Evaluation of endothall alone and pre-mixed with diquat for flowering rush control. APMS + WAPMS *
- Ortiz, M.F, Heilman, M.A, (2019). Interaction of florpyrauxifen-benzyl with four herbicides for curlyleaf pondweed control. APMS + WAPMS *
- Tanz, K., Ortiz, M.F, Nissen, S.J, Gray, C.J, (2018). Comparing efficacy of endothall + diquat and endothall + copper formulations for Egeria densa control. APMS *
- Ortiz, M., Nissen, S.J, Gray, C., (2018). Efficacy of endothall and endothall+2,4-D for curlyleaf pondweed (Potamogeton crispus) control under simulated fall conditions. NEAPMS *
- Ortiz, M., Nissen, S.J, Gray, C., (2018). Endothall behavior in several aquatic weeds. NEAPMS *
- Silva, P.V, Sebastian, D.J, Clark, S.L, Ortiz, M., Figueiredo, M., Dayan, F.E, Monquero, P.A, Christoffoleti, P.J, Nissen, S.J, (2018). Indaziflam, imazapic and amicarbazone sorption, desorption and interception by sugarcane (Saccharum officinarum) residues. Weed Science Society of America *
- Silva, P.V, Nissen, S.J, Clark, S., Sebastian, D., Ortiz, M.F, Monquero, P.A, Christoffoleti, P.J, (2018). Interceptacao, adsorcao e dessorcao de herbicidas residuais em palha de cana-de-acucar. Congresso Brasileiro da Ciencia das Plantas Daninhas *
- Silva, P.V, Clark, S., Sebastian, D., Ortiz, M.F, Monquero, P.A, Christoffoleti, P.J, Nissen, S.J, (2018). Sorcao de herbicidas residuais em solos com diferentes caracteristicas fisico-quimicas. Congresso Brasileiro da Ciencia das Plantas Daninhas *
- Silva, P.V, Clark, S.L, Sebastian, D.J, Ortiz, M., Falerri, M., Figueiredo, M., Monquero, P.A, Christoffoleti, P.J, Nissen, S.J, (2018). Sorption and desorption of indaziflam, imazapic, and amicarbazone in soils with varying physical and chemical properties. Weed Science Society of America *
- Kessler, K., Ortiz, M., Nissen, S., Ratajczyk, W., Wersal, R., (2017). Absorption rates of 2,4-D butoxyethyl ester and 2,4-D amine by Eurasian watermilfoil. WSWS + WAPMS *
- Scarpin, J., Ortiz, M., Nissen, S., Gray, C., (2017). Efficacy of Aquathol and KFD-94-10 for curlyleaf pondweed (Potamogeton crispus) control under simulated fall conditions. WSWS + WAPMS *
- Ortiz, M.F, Scarpin, J., Nissen, S.J, Gray, C.J, (2017). Efficacy of endothall (Aquathol K) and endothall+2,4-D (Chinook) for curlyleaf pondweed (Potamogeton crispus) control under simulated fall conditions. APMS *
- Ortiz, M., Kessler, K., Nissen, S.J, Gray, C., (2017). Endothall behavior in Eurasian watermilfoil (Myriophyllum spicatum) and hydrilla (Hydrilla verticillata). ICAIS *
- Ortiz, M., Nissen, S.J, Kessler, K., Gray, C., (2017). Translocation of 14C-endothall in Eurasian watermilfoil and two hydrilla biotypes. WSWS + WAPMS *
- Ortiz, M.F, Nissen, S.J, Gray, C.J, (2017). Translocation of 14C-endothall in Eurasian watermilfoil and two hydrilla biotypes. NEAPMS *
- Ortiz, M., Nissen, S.J, Gray, C., (2017). Translocation of 14C-endothall in Eurasian watermilfoil, curlyleaf pondweed and two hydrilla biotypes. APMS *
- Ortiz, M., Nissen, S.J, Gray, C., (2017). Translocation of endothall in Eurasian watermilfoil and two hydrilla biotypes. MAPMS *
- Kessler, K., Ortiz, M., Nissen, S.J, (2016). 2,4-D metabolism in Eurasian watermilfoil (Myriophyllum spicatum) and several 2,4-D tolerant milfoil hybrid populations (M. spicatum x M. sibiricum). APMS *
- Ortiz, M., Kessler, K., Nissen, S.J, Wersal, R., Rataczyk, W., (2016). Absorption rates of 2,4-D Butoxyethyl ester and 2,4-D amine by Eurasian watermilfoil. WAPMS *
- Ortiz, M., Kessler, K., Nissen, S.J, Wersal, R., Ratajczyk, W., (2016). Absorption rates of 2,4-D butoxyethyl ester and 2,4-D amine by Eurasian watermilfoil. APMS *
An asterisk (*) at the end of a publication indicates that it has not been peer-reviewed.
- da Silva, P.V, Dias, R.C, Ortiz, M.F, Monquero, P.A, (2022). Transformacao dos herbicidas por fotodegradacao na superficie do solo e em agua: Herbicidas no ambiente; Comportamento e destino. Editora UFV
- Dayan, F.E, Barker, A., Bough, R., Ortiz, M., Takano, H., Duke, S.O, (2019). Herbicide Mechanisms of Action and Resistance: Comprehensive Biotechnology. Elsevier
Publications | Book Chapters
An asterisk (*) at the end of a publication indicates that it has not been peer-reviewed.
Publications | Fact Sheets
- Hadfield, J., Zesiger, C., Pace, M., Ortiz, M., Ransom, C., (2024). Parrot Feather (Myriophyllum aquaticum) Identification and Management in Waterways. USU Extension
An asterisk (*) at the end of a publication indicates that it has not been peer-reviewed.
Publications | Journal Articles
Academic Journal
- Nissen, S.J, Clark, S.L, Seedorf, R., Ortiz, M.F, (2025). Indaziflam and imazapic applications to Aegilops cylindrica spikelets and Bromus tectorum seeds inhibits plant establishment. Weed Science
- Adeyemi, O.E, Westra, E.P, Ransom, C.V, Creech, J.E, Ortiz, M.F, (2025). Status of kochia (Bassia scoparia) herbicide resistance in the Western US. Outlooks on Pest Management, 36:2, 55-58.
- Souza, A.S, Leal, J.F, Montgomery, J.S, Ortiz, M.F, Araujo, A.L, Morran, S., Figueiredo, M.R, Langaro, A.C, Zobiole, L.S, Nissen, S.J, Gaines, T.A, Pinho, C.F, (2023). Non-target-site resistance due to rapid physiological response in 2,4-D resistant Conyza sumatrensis: Reduced 2,4-D translocation and auxin-induced gene expression. Pest Management Science
- Ortiz, M.F, Nissen, S.J, Gray, C.J, (2022). Endothall absorption and translocation by curly-leaved and sago pondweed. Journal of Aquatic Plant Management, 60:1, 35-39.
- Ortiz, M.F, S.J, Dayan, E, (2022). Endothall and florpyrauxifen-benzyl behavior in Hydrilla (Hydrilla verticillata) when applied in combination. Weed Science, 70, 537-542.
- Ortiz, M.F, Nissen, S.J, Thum, R.A, Heilman, M.A, Dayan, F.E, (2020). Current status and future prospects for aquatic weed management. Outlooks on Pest Management, 31:6, 270-275.
- Ortiz, M.F, Nissen, S.J, Gray, C.J, (2019). Endothall behavior in Myriophyllum spicatum and Hydrilla verticillata. Pest Management Science, 75, 2942-2947.
An asterisk (*) at the end of a publication indicates that it has not been peer-reviewed.
Publications | Other
An asterisk (*) at the end of a publication indicates that it has not been peer-reviewed.