Professor and Chair
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.
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.
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 3150 - Weed Biology & Management - (Fall term) 4 credits.
ENTOM/PLSCS 4440 - Integrated Pest Management (Spring term) - 4 credits.
Course website: http://instruct1.cit.cornell.edu/courses/ipm444/
Graduate Courses Taught:
PLSCS 6140 Weed Ecology and Management (Spring term) - 3 credits - offered in odd years only.
Awards and Honors
- 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
- Professor of Merit (2012) CALS - Cornell University
- 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.
- Cordeau, S., Smith, R. G., Gallandt, E. R., Brown, B., Salon, P., DiTommaso, A., & Ryan, M. R. (2017). Disentangling the Effects of Tillage Timing and Weather on Weed Community Assembly. Agriculture. 7:66.
- Cordeau, S., Smith, R. G., Gallandt, E. R., Brown, B., Salon, P., DiTommaso, A., & Ryan, M. R. (2017). Timing of Tillage as a Driver of Weed Communities. Weed Science. 65:504-514.
- DiTommaso, A., Milbrath, L. R., Morris, S. H., Mohler, C. L., & Biazzo, J. (2017). Seedbank dynamics of two swallowwort (Vincetoxicum) species. Invasive Plant Science and Management. 10:136-142.
- Liebert, J. A., DiTommaso, A., & Ryan, M. R. (2017). Rolled Mixtures of Barley and Cereal Rye for Weed Suppression in Cover Crop-based Organic No-Till Planted Soybean. Weed Science. 65:426-439.
- Mohler, C. L., Iqbal, J., Shen, J., & DiTommaso, A. (2016). Effects of water on recovery of weed seedlings following burial. Weed Science. 64:285-293.
- DiTommaso, A., Averill, K. M., Hoffmann, M. P., Fuchsberg, J. R., & Losey, J. E. (2016). Integrating insect, resistance, and floral resource management in weed control decision-making. Weed Science. 64:743-756.
- Averill, K. M., DiTommaso, A., Whitlow, T. H., & Milbrath, L. R. (2016). Photosynthetic performance of invasive Vincetoxicum species (Apocynaceae). Invasive Plant Science and Management. 9:171-181.
Presentations and Activities
- Effects of long-term management on soil organic matter and weed competition in organic soybean. 2015. ASA, CSSA, and SSSA International Annual Meeting. ASA Section: Agronomic Production Systems.
- 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.