Professor and Chair, School of Integrative Plant Science Soil and Crop Sciences Section
The overall goal of my research program is to study and gain a more in depth understanding of the basic biological/ecological principles governing agricultural and environmental weed population dynamics that ultimately lead to the development and implementation of safe, effective, sustainable and economically viable weed management strategies. To achieve this goal my research program comprises several major thrusts.
Biological weed management
Primary areas of scholarship focus on:
Effects of the environment on weed species. Evaluation of the effects of biotic (e.g. plant competition; selective disease and insect predation) and abiotic factors (e.g. light, fertility, salinity) on the seed biology, growth and reproduction of important agricultural weeds (velvetleaf, pigweeds, common ragweed) and introduced invasive plant species (e.g. swallow-wort, mugwort) of natural communities in the Northeastern United States.
Effects of weeds on their environment. Examination of the direct and indirect impact of weeds in their habitat. Includes research on the effect of the invasive alien vine pale swallow-wort (Vincetoxicum rossicum) [Apocynaceae] on monarch butterfly populations, arbuscular mycorrhizal fungal (AMF) populations, and native plant species.
Manipulation of the environment to suppress weeds. Research aimed at modifying the biotic and/or abiotic environment of troublesome weeds in both cropland and natural systems to improve control. These tactics can be used either alone or as part of an integrated management strategy. Manipulation of the biotic environment is primarily achieved through the use of selective biological control agents such as fungal pathogens and insects while abiotic manipulations focus largely on soil fertility management.
- Menalled, U.D., S.J. Pethybridge, C.J. Pelzer, R.G. Smith, A. DiTommaso, and M.R. Ryan. 2021. High seeding rates and low soil nitrogen environments optimize weed suppression and profitability in organic no-till planted soybean. Frontiers in Agronomy May 2021/Volume 3/Article 678567. https://doi.org/10.3389/fagro.2021.678567
- Bhaskar, V., R.R. Bellinder, S. Reiners, A.S. Westbrook, and A. DiTommaso. 2021. Significance of herbicide order in sequential herbicide applications to target weeds in a sunn hemp living mulch. Weed Technology. doi: 10.1017/wet.2021.15
- Little, N.G., A. DiTommaso, A.S. Westbrook, Q.M. Ketterings, and C.L. Mohler. 2021. Effects of fertility amendments on weed growth and weed-crop competition: A review. (Invited paper). Weed Science 69(2):132-146 https://doi.org/10.1017/wsc.2021.1
- Law E.P., C.J. Pelzer, S. Wayman, A. DiTommaso, and M.R. Ryan. 2021. Strip-tillage renovation of intermediate wheatgrass (Thinopyrum intermedium) for maintaining grain yield in mature stands. Renewable Agriculture and Food Systems 1–7. https://doi.org/10.1017/S1742170520000368
- DiTommaso, A., L.R. Milbrath, C.A. Marschner, S.H. Morris, and A.S. Westbrook. 2021. Seed germination ecology of meadow knapweed (Centaurea × moncktonii) populations in New York State, USA. Weed Science 69(1):111-118. https://doi.org/10.1017/wsc.2020.86
- Menalled, U.D., K.A. Bybee-Finley, R.G. Smith, A. DiTommaso, S.J. Pethybridge, and M.R. Ryan. 2020. Soil-mediated effects on weed-crop competition: Elucidating the role of annual and perennial intercrop diversity legacies. Agronomy 2020, 10, 1373. https://doi:10.3390/agronomy10091373
- Shen, H., S. Dong, A. DiTommaso, S. Li, J. Xiao, M. Yang, J. Zhang, X. Gao, Y. Xu, Y. Zhi, S. Liu, Q. Dong, W. Wang, and P. Liu. 2020. Eco-physiological processes are more sensitive to simulated N deposition in leguminous forbs than non-leguminous forbs in an alpine meadow of the Qinghai-Tibetan Plateau. 2020. Science of the Total Environment 744 (2020) 140612. https://doi.org/10.1016/j.scitotenv.2020.140612
- Sousa-Ortega, C., A. Royo-Esnal, A. DiTommaso, J. Izquierdo, I. Loureiro, A.I. Marí, F. Cordero, M. Vargas, M. Saavedra, J.A. Paramio, J.L. Fernández, J. Torra, J.M. Urbano. 2020. Modeling the emergence of Centaurea diluta, an increasingly troublesome weed in Spain. Weed Science 68(3):268-277.
- Zhu, J., Wen Liang, Siyu Yang, Huifu Wang, Chunhua Shi, Shuo Wang, Weijun Zhou, Qiang Lu, Faisal Islam, Weidong Xu, and A. DiTommaso. 2020. Safety of oilseed rape straw mulch of different lengths to rice and its suppressive effects on weeds. Agronomy 2020, 10, 201; doi:10.3390/agronomy10020201
- Zhu, J., J. Wang, A. DiTommaso, C. Zhang, G. Zheng, W. Liang, F. Islam, C. Yang, X. Chen, and W. Zhou. 2020. Weed research status, challenges, and opportunities in China. Crop Protection 134(2020) 104449. https://doi.org/10.1016/j.cropro.2018.02.001
- Youngerman, C.Z., A. DiTommaso, J.E. Losey, and M.R. Ryan. 2020. Cover crop and weed seed preference of four common weeds seed predators. Renewable Agriculture and Food Systems 35(5):522-532. doi.org/10.1017/S1742170519000164
- Bhaskar, V., R.R. Bellinder, S. Reiners, and A. DiTommaso. 2020. Reduced herbicide rates for control of living mulches and weeds in fresh market tomato. Weed Technology 34(1):55-63. doi.org/10.1017/wet.2019.81
- Ball, M.G., B.A. Caldwell, A. DiTommaso, L.E. Drinkwater, C.L. Mohler, R.G. Smith, and M.R. Ryan. 2019. Weed community structure and soybean yields in a long-term organic cropping systems experiment. Weed Science 67(6):673–681. doi: 10.1017/wsc.2019.44
- Iqbal, J., A. DiTommaso, M. Ishaq, A. Rehmani, K. Jabran, S. Hussain, W. Nasim, S. Fahad, M.A. Shehzad, and A. Ali. 2019. Purple nutsedge (Cyperus rotundus) control through interference by summer crops. International Journal of Agriculture and Biology 21(5):1083-1088. doi: 10.17957/IJAB/15.0997
- Milbrath, L.R., J. Biazzo, A. DiTommaso, and S. Morris. 2019. Impact of Abrostola asclepiadis combined with other stressors on invasive swallow-worts (Vincetoxicum species). Biological Control. 130(3): 118-126. https://doi.org/10.1016/j.biocontrol.2018.11.005
- Mohler, C. L., Caldwell, B. A., Marschner, C. A., Cordeau, S., Maqsood, Q., Ryan, M. R., & DiTommaso, A. (2018). Weed Seedbank and Weed Biomass Dynamics in a Long-Term Organic Vegetable Cropping Systems Experiment. Weed Science. 66:611-626.
- Youngerman, C. Z., DiTommaso, A., Curran, W. S., Mirsky, S. B., & Ryan, M. R. (2018). Corn Density Effect on Interseeded Cover Crops, Weeds, and Grain Yield. Agronomy Journal. 110:2478-2487.
- DiTommaso, A., Stokes, C. A., Cordeau, S., Milbrath, L. R., & Whitlow, T. H. (2018). Seed-Dispersal Ability of the Invasive Perennial Vines Vincetoxicum nigrum and Vincetoxicum rossicum. Invasive Plant Science and Management. 11:10-19.
- Zhu, J., Wang, J., DiTommaso, A., Zhang, C., Zheng, G., Liang, W., Islam, F., Yang, C., Chen, X., & Zhou, W. (2018). Weed research status, challenges, and opportunities in China. Crop Protection.
- Averill, K. M., Mortensen, D. A., Smithwick, Erica A. H.,, Kalisz, S., McShea, W. J., Bourg, N. A., Parker, J. D., Royo, A. A., Abrams, M. D., Apsley, D. K., Blossey, B., Boucher, D. H., Caraher, K. L., DiTommaso, A., Johnson, S. E., Masson, R., & Nuzzo, V. A. (2018). A regional assessment of white-tailed deer effects on plant invasion. AoB Plants. 10.
- Mohler, C. L., Taylor, A. G., DiTommaso, A., Hahn, R. R., & Bellinder, R. R. (2018). Effects of Incorporated Rye and Hairy Vetch Cover Crop Residue on the Persistence of Weed Seeds in the Soil. Weed Science. 66:379-385.
- Bhaskar, V., Bellinder, R. R., DiTommaso, A., & Walter, M. F. (2018). Living Mulch Performance in a Tropical Cotton System and Impact on Yield and Weed Control. Agriculture. 8.
- Cordeau, S., Smith, R. G., Gallandt, E. R., Brown, B., Salon, P., DiTommaso, A., & Ryan, M. R. (2017). How do weeds differ in their response to the timing of tillage? A study of 61 species across the northeastern United States. Annals of Applied Biology. 171:340-352.
- Young, S. L., Clements, D. R., & DiTommaso, A. (2017). Climate Dynamics, Invader Fitness, and Ecosystem Resistance in an Invasion-Factor Framework. Invasive Plant Science and Management. 10:215-231.
- Jernigan, A. B., Caldwell, B. A., Cordeau, S., DiTommaso, A., Drinkwater, L. E., Mohler, C. L., & Ryan, M. R. (2017). Weed abundance and community composition following a long-Term organic vegetable cropping systems experiment. Weed Science. 65:639-649.
Presentations and Activities
- Climate change and weed migration: What do we know and what next? 21st Australasian Weeds Conference. September 2018. The Weed Society of New South Wales Inc., on behalf of the Council of Australasian Weed Societies Inc.. Sydney, Australia.
- Impact of drought on competition between ivyleaf morningglory and corn. Northeastern Plant, Pest, and Soils Conference. July 2018. Northeastern Weed Science Society. Philadelphia, PA United States.
- When it comes to tillage, timing matters and drives weed communities. 18th European Weed research Society Symposium. June 2018. European Weed research Society. Ljubljana, Slovenia.
- Seed germination ecology of meadow knapweed (Centaurea x moncktonii) populations in New York State. Annual Meeting of the Weed Science Society of America. January 2018. Weed Science Society of America. Arlington, VA.
- Weed seedling emergence in two extreme years in Central New York State. Annual Meeting of the Weed Science Society of America. January 2018. Weed Science Society of America. Arlington, VA.
- New F.A.C.E.S.: Fostering Agricultural Extension and Communication Students – A USDA‐HEMSP Supported Project at Cornell University. NACTA Annual Conference. June 2014. North American Colleges and Teachers of Agriculture (NACTA),. Bozeman, MT .
- Climate change and the ecology and management of weeds: What do we know? 2013 Northeast Region Certified Crop Adviser (NRCCA) Annual December Training Meeting. . December 2013. Northeast Region Certified Crop Adviser (NRCCA) . Syracuse, NY.
- Update: Invasive plants of increasing concern. 7th Annual Invasive Species Track. Cornell Cooperative Extension In-service Agriculture and Food Systems Program. . November 2013. CCE. Ithaca, NY.
Awards & Honors
- Fellow (2019) Northeastern Weed Science Society
- Stephen H. Weiss Presidential Fellow (2017) Cornell University
- Outstanding Researcher Award (2018) Northeastern Weed Science Society
- CSSA Crop Science Teaching Award (2015) Crop Science Society of America
- Excellene in IPM Award (2015) New York State Integrated Pest Management Program
My teaching philosophy is founded on respect both for students as individuals and for the pedagogical process. My approach is based on the following belief: As students become active observers, they will be motivated to seek and learn new ways to discover, problem-solve, collaborate, and develop critical thinking. Thus, it is my role and responsibility as a teacher, to seek ways to stimulate, encourage, and enhance students` curiosity.
Undergraduate Courses Taught:
- PLSCS 2940: Introduction to Ag Machinery
- PLSCS 3150 - Weed Biology & Management - (Fall term) 4 credits.
- ENTOM/PLSCS 4440 - Integrated Pest Management (Spring term) - 4 credits. Course website:
Graduate Courses Taught:
- PLSCS 6140 Weed Ecology and Management (Spring term) - 3 credits - offered in odd years only.
235 Emerson Hall
Ithaca, NY 14853
ad97 [at] cornell.edu
- Soil and Crop Sciences
- Master of Science
- Bachelor of Science
Toni in the news
- School of Integrative Plant Science
- Soil and Crop Sciences Section
- Natural Resources and the Environment
- Cornell University Agricultural Experiment Station
- School of Integrative Plant Science
- Horticulture Section