Jack C. Comstock was born in Detroit, Michigan, on June 13, 1943. He received his B.S. degree in biological science in 1965 and his Ph.D. degree in plant pathology in 1971 from Michigan State University. Comstock was a research associate in the Botany and Plant Pathology Department at Iowa State University from 1971 to 1974. From 1974 to 1989, he was an associate sugarcane pathologist at the Experiment Station of the Hawaiian Sugar Planters Association, Aiea, Hawaii. Since 1989, he has been a research plant pathologist at the USDA-ARS Sugarcane Field Station in Canal Point (CP), Florida, and became research leader in 2004.
Comstock’s career has centered on sugarcane pathology and development of disease-resistant, high-yielding cultivars benefiting domestic and international industries. Comstock has provided valuable assistance to U.S. and international scientists in the confirmation of economically important diseases affecting sugarcane, including leaf scald in Guatemala (1995) and Mexico (1993); yellow leaf in Ecuador, Guatemala, and Nicaragua (2002); orange rust in Guatemala (2008), Costa Rica, El Salvador, Mexico, Nicaragua, and Panama (2009), and Ivory Coast and Cameroon (2011); and ratoon stunt in Pakistan (2011). Comstock and colleagues conducted Orange Rust Workshops (2009 and 2010) that were video-streamed to eight countries in the Western Hemisphere with more than 500 participants. He has been invited to advise on disease outbreaks in Malaysia and Ecuador on sugarcane smut (1992); in Jamaica, at the request of the USDA Foreign Agricultural Service to evaluate an unknown disease (1999); and in Nicaragua, to diagnose red stripe (2003) and orange rust (2007). He has been invited to present lectures and to review sugarcane programs in China by Fujian Agriculture and Forestry University (2007) and the Guangxi Academy of Agricultural Sciences (2008) and to give feature presentations at the International Association of Professionals in Sugar and Integrated Technologies (IAPSIT) Workshop in Nanning, China. In addition, Comstock has been invited to Brazil (2009) by Embrapa to visit six research centers and universities to present seminars on sugarcane pathology and cultivar development and to India (by IAPSIT) and Japan (by Okinawa Prefecture Research Center) to present lectures. Since 1978, Comstock has also been on visits to review sugarcane industries and give presentations in Australia, Fiji, Republic of China, the Philippines, Mauritius, Indonesia, Thailand, France, United Kingdom, Papua New Guinea, South Africa, Colombia, Costa Rica, Honduras, and Mexico.
Sugarcane clones developed by Comstock’s team are critical to the Florida sugarcane industry, where more than 95% of the acreage is planted in CP clones. Comstock chairs the Sugarcane Variety Committee through which varieties are released. He also leads the USDA-ARS Sugarcane Field Station, one of the tripartite cooperators along with the University of Florida EREC, and the Florida Sugar Cane League in the development of CP cultivars.
Comstock has been instrumental in assisting sugarcane breeding and pathology programs in numerous developing countries, providing specific genotypes of sugarcane germplasm as seedcane and as true seed from sexual crosses. He is lead scientist on more than 10 agreements, facilitating evaluation of germplasm for enhanced yield and disease resistance. In Central America, CP cultivars contribute significantly to the regional billion-dollar industry and to the overall economy of these developing countries. Currently, CP varieties are planted on 24% of the 139,000 sugarcane acres in Costa Rica; 76% of 435,000 acres in Guatemala; 33% of 1,705,600 acres in Mexico; 90% of 97,700 acres harvested by two of the four largest mills in Nicaragua; and an estimated 70 and 15% of the sugarcane acreage in El Salvador and Panama, respectively. CP 88-1165, a cultivar jointly released by Guatemalan and U.S. scientists, now has replaced CP 72-2086, an orange rust-susceptible cultivar, on 35% of the acreage in Guatemala and produces 9% more sugar per acre.
Comstock has initiated new cooperative research agreements with several organizations in Central America to evaluate new clones for commercial production, and he has hosted the last four annual seminars to assist in their development. In Pakistan, Comstock’s contributions have had a significant impact on the country’s sugarcane selection program. Pakistani sugarcane industry occupies 2.5 million acres and employs more than 1 million people. Its production has been low. An older variety derived from CP germplasm now comprises 50% of their acreage. Comstock has provided biparental seed to multiple Pakistani research institutes to help them identify superior commercial cultivars. Newer cultivars derived from CP crosses are 25% more productive and have higher sucrose than current commercial varieties in Pakistan.
Comstock has provided training to more than 50 international agriculturalists for 1- to 2-week periods on disease diagnosis, disease screening, and sugarcane pathology, and he has hosted eight international scientists for 6 months or longer. This training has improved disease identification and diagnosis for the selection of resistant cultivars in their home countries.
Jack Comstock has been a member of APS for more than 45 years and served on the Tropical Disease Committee (1985–1988, 1991–1994). He served as a member (1988–2005) and chair (2005–2010) of the Sugarcane Pathology Committee of the International Society of Sugar Cane Technologists (ISSCT) and is the only person to attend all 10 of the ISSCT Sugarcane Pathology Workshops that began in 1986. He has been a member of the American Society of Sugar Cane Technologists since 1989 and was recognized for his outstanding contributions in 2012. He and members of the cultivar development team received the 2011 ARS Technology Transfer Award for the sustained transfer of high-yielding varieties to Florida and international growers. This award is testimony to Comstock’s altruistic efforts, where team members represented five organizations outside of the USDA, including industry and university members. Comstock has 200 publications, of which 101 are peer-reviewed publications (including 30 CP sugarcane cultivar registrations) and 17 are book chapters. He has also served on the committee that compiled the names of sugarcane diseases for the International Society for Plant Pathology. Since 2003, he has been a referee for Sugar Cane International and reviews numerous sugarcane pathology manuscripts annually. Comstock engages pressing problems of germplasm exchange, emerging diseases, and identification of new sources of genetic diversity that face the entire international sugarcane community.