Overview

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.

Research Focus

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 develops tools to select for broccoli that consistently avoids premature arrest that is normally induced by high temperatures during the main growing season, and characterizes diverse broccoli germplasm for adaptation to Eastern growing conditions. I support my extension work through applied research on physiology of summer cover crops in relation to their competitiveness against weeds, and their ability to improve soil condition.

Outreach and Extension Focus

I am the primary contact at Cornell 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. In association with the broccoli project, I am leading the extension component that will develop current production recommendations, grower marketing networks and postharvest infrastructure in Western New York, Piedmont Virginia, Appalachian North Carolina, Central South Carolina, and the Low Country in South Carolina, Georgia and Florida. I also lead the extension for buckwheat grain production, and am a resource on non-pathogenic storage disorders in cabbage.

Instruction Focus

I taught Plant Biology 7420, Environmental Cues in Plant Development in Spring 2010. I also guest lecture on phosphorus nutrition and broccoli development in horticulture courses.

Additional Links

• Björkman Lab home page
• Broccoli
• Buckwheat production
• Cover Crops for Vegetable Growers
• People in the lab
• Link to VIVO profile

Selected Publications

• Mastouri, F., T. Björkman and G.E. Harman. 2010 Seed treatments with Trichoderma harzianum alleviates biotic, abiotic and physiological stresses in germinating seeds and seedlings. Phytopathology. In Press
• Björkman, T., R.R. Bellinder, R.R. Hahn and J.W.Shail. 2008. Buckwheat Cover Crop Handbook. Cornell University. 18 pp.
• Duclos, Denise V. and Thomas Björkman. 2008. Meristem gene expression during reproductive development in Brassica oleracea. Journal of Experimental Botany 59: 421-433 doi:10.1093/jxb/erm327
• Mochizuki, M.J., A. Rangarajan, R.R. Bellinder, T. Björkman, H. M. van Es. 2008. Rye mulch managment affects short-term indicators of soil quality in the transition to conservation tillage for cabbage. HortScience. 43:862-867.
• Harman, G.E., T. Björkman, K. Ondik, M. Soresh. 2008. Changing paradigms on the mode of action and uses of Trichoderma spp. for biocontrol. Outlooks in Pesticide Managment. 19:24-29. doi: 10.1564/19feb08
• Mochizuki, M.J., A. Rangarajan, R.R. Bellinder, T. Björkman, H. M. van Es. 2007. Overcoming compaction limitations on cabbage growth and yield in the transition to reduced tillage. HortScience. 42:1690-1694.
• Labate, Joanne A., Larry D. Robertson, Angela M. Baldo, and Thomas Björkman. 2006. Inflorescence identity-gene alleles are poor predictors of inflorescence type in broccoli and cauliflower. J. Amer. Soc. Hortic. Sci. 131: 667-673
• Björkman, T. 2004. Effect of Trichoderma colonization on auxin-mediated regulation of root elongation. Plant Growth Regulation 43: 89-92 doi:10.1023/B:GROW.0000038260.85276.82

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