top of page
Robert L Zimdahl.jpg


Robert L. Zimdahl, Professor Emeritus, Colorado State University Department of Agricultural Biology, has spent his 37-year academic career challenging conventional scientific thought about agriculture. Trained as a weed scientist with a specialty in herbicides, Zimdahl gradually shifted his interests to ethical concerns about modern agricultural practices. Since his retirement from CSU in 2005, he has traveled to Iran, Pakistan, Lebanon, Japan, Morocco, the Philippines, Canada, Thailand, Mongolia, and Turkey (three times) to share with other international experts his concerns about agricultural technology.


Invited Lectures


Zimdahl, R. L. 2010. Plenary paper. 22nd Asian-Pacific Weed Science Society

          (APWSS) Conference. Lahore, Pakistan, March 8-12, 2010.

Zimdahl, R. L. 2011. Invited Keynote Speaker - 22nd Asian-Pacific Weed Sci. Soc.

          Lahore, Pakistan, March.

Zimdahl, R. L. 2011.  Invited Keynote Speaker - 11th Iranian Crop Science Congress.

          Tehran, Iran, July

Zimdahl, R. L.

          2017. Invited Keynote Speaker. Ethics, Agriculture, and The Environment.

                    First Turkish Congress on Agriculture and Food Ethics. Ankara, Turkey.

          2019. Invited keynote speaker. Sustainable Agriculture and The Environment -

                    An Ethical Perspective. Second Turkish Congress on Agriculture and

                    Food Ethics. Izmir, Turkey.

          2021. Invited Keynote Speaker. Agricultural Sustainability and Denial.

                    Third Turkish Congress on Agriculture and Food Ethics. Istanbul, Turkey. Virtual.

Zimdahl, R. L. 2017. Invited Keynote Speaker - 26th Asian-Pacific Weed Sci. Soc.

          Kyoto, Japan, September 2017.

Zimdahl, R. L. 2018. Invited Keynote Speaker - Annual meeting Canadian Weed

          Science Society. Niagara Falls, Canada. November 2018.

Zimdahl, R. L. 2020. Invited Webinar.  Weed Science For Sustainable Agriculture

          and Environment- An Ethical Perspective. School of Postgraduate Studies.

          Tamil Nadu Agricultural University, Coimbatore,India

Zimdahl, R. L. 2021. Agricultural Sustainability and Denial. Proceedings of the

          3rd International Congress on Agricultural and Food Ethics. Istanbul, Turkey.

          November 5-6. Pp 44-57.

Zimdahl, R.L. 2022. Invited webinar Weed Science, Sustainable Agriculture,

          and Environment- An Ethical Perspective. University of the Philippines Los Banos.

          Feb. 22.


Origins of Morality

There is an agricultural moral code—do unto others. That code we often assume was based on the Bible, but probably had its origins in the mutual-help ethics of early agriculture. Much of modern morality grew out of the imperatives of early farm life. (On Living by Robert L. Zimdahl)

bottom of page