 He moved to New Orleans, Louisiana in the 1980s and served as an adjunct professor at Tulane University.Harlan published a variety of papers in the area of crop biodiversity, and publicized his concerns that modern agricultural practices were contributing to the extinction of older, traditional varieties of crops.As a scientist Harlan had two complementary research interests; the practical work of breeding economically important crops for desirable traits such as disease resistance or higher yield, and archaeobotany, the archeological study of the origins of crop domestication.