Dr Hall is an Emeritus Professor who retired in 2003. For 32 years he held a joint appointment as a Professor of Plant Physiology at the University of California, Riverside and as a Crop Ecologist in the California Agricultural Experiment Station. He collaborated with African colleagues in education and the development and extension of improved cowpea varieties and management methods, breeding seven cowpea varieties. He received the USDA Secretary's Honor Award in 2001 and the USAID/BIFAD Chair's Award for Scientific Excellence in 2000. In 1993 he was elected a Fellow in the Crop Sciences Society of America and the American Society of Agronomy. He wrote Crop Responses to Environment in 2001 and was the co-Editor of four scientific books. He was the author or co-Author of 173 scientific journal articles, chapters and reviews. In recent years he has advised agencies of the United Nations and various foundations concerning the types of agricultural research needed to promote rural development in Africa.
