Thomas Björkman
Professor, School of Integrative Plant Science Horticulture Section Cornell AgriTech

My research covers the range from discovering basic biological principles, to direct application in commercial settings. I study the effects of environmental stimuli on growth and development, particularly as applied to vegetable production. Current work in flowering includes discovering how temperature regulates the transition from inflorescence to flower in broccoli using the tools of functional genomics. I also have a strong interest in improving agricultural production through better integration, including work on cover crops that fill management goals for vegetable producers. Cover crops have physiological processes with valuable management benefits that complement the needs of vegetable growers. I am leading two multi-state research and extension teams. One seeks to make summer cover crops a standard practice on organic vegetable farms in the Great Lakes region. The other will establish a year-round Eastern broccoli industry by developing commercial varieties from existing germplasm that tolerates our growing conditions, developing grower networks in six Eastern locations that can collectively provide year-round harvest, and developing a distribution network to serve major Eastern markets.
Interests
Vegetable crop physiology
Cover crops
Establishing year-round Eastern broccoli industry
Recent Research
- Developmental processes that make vegetables valuable or interesting
- Root growth and interactions with soil biota
- Cover crop integration in vegetable cropping systems
A major are of applied research is in the mechanism whereby cover crops can overcome limitations in soil quality and contribute to weed management in vegetable production systems. Significant funding was obtained in 2009 to develop multi-institutional programs to this end.
My basic research focuses on how development is arrested in the inflorescence of Brassica oleracea. A superb model system for this process is broccoli, a close relative of the well-studied Arabidopsis, and, with cauliflower, an extreme expression of such developmental arrest. Furthermore, precise control of this arrest is a critical management issue for a billion-dollar part of the vegetable industry. My lab investigates the role of homeotic genes believed to control developmental transition during this process.
My related applied research involves facilitating selection for broccoli that consistently avoids premature arrest that is normally induced by high temperatures during the main growing season. Major funding was received in 2010 for and integrated project to establish an eastern broccoli industry based on new varieties derived from these selections.
Publications
Visit my ResearchGate profile
Extension and outreach
I am the primary contact for cover crop use in vegetable production. The intensity of vegetable production necessitates active soil improvement regimes. Cover crops play an essential role in soil improvement as well as pest and weed management and biological nitrogen fertilization. Introduction of cover crops requires a systemic analysis of production systems, their constraints and limitations. Outreach on soil improving aspects are designed to fill prescriptions produced by the Cornell Soil Health Test. This work is particularly valued by the rapidly growing organic industry. Current new outreach activity focuses on the use of short cycle cover crops during the growing season, which is a useful practice for which guidelines have not yet been established. Supporting my extension work, I do applied research on physiology of summer cover crops in relation to their competitiveness against weeds, and their ability to improve soil condition. I also lead the extension for buckwheat grain production, and am a resource for non-pathogenic storage disorders in cabbage.
Awards & Honors
- Fellow (2017) American Society for Horticultural Science
- Fellow (2012) Atkinson Center for a Sustainable Future
Courses Taught
- PLHRT 9900: Doctoral Dissertation Research
Contact Information
205 Hedrick Hall
635 W North St.
Geneva, NY 14456
tnb1 [at] cornell.edu
More information
- Björkman Lab Website
- Cover crops for vegetables
- Developing an Eastern Broccoli Industry Page
- Eastern Broccoli Twitter feed
Graduate Fields
- Horticulture
- Plant Biology
Education
- Doctorate
Cornell University
1987
- Bachelor of Science
University of California, Davis
1979
Thomas in the news

News
Larger organic farms operate more like conventional farms and use fewer sustainable practices than smaller organic farms, according to a new study that also provides insight into how to increase adoption of sustainable practices.
- Cornell Atkinson
- Charles H. Dyson School of Applied Economics and Management
- Department of Global Development

CALS Magazine
News
This project is no small undertaking. One of the challenges stems from the fact that broccoli was originally cultivated for Mediterranean climates, so growing it in the U.S. confuses the plant’s developmental cues. Broccoli flower buds and heads...
- Charles H. Dyson School of Applied Economics and Management
- Agriculture
- Food