Meet the Peach Team

At Clemson University in South Carolina, a group of faculty researchers, county extension agents and specialists are working together to solve the problems of the peach industry. The Peach Team is an interdisciplinary team of researchers and extension agents that provide research-based information to advance the fruit industry in South Carolina and beyond.

Dr. Greg Reighard has been a research and extension horticulturist for 34 years at Clemson University. His field research has involved rootstock evaluation, growth regulators, manipulating peach tree dormancy/flowering, crop load management strategies, modeling fruit maturity, and adapting mechanical technologies for training systems. His lab has conducted genomics research on dormancy (Evg mutant) and rootstock resistance to nematodes and peach tree short life, where he co-developed Guardian® rootstock as well as its eventual PVP and trademark. Dr. Reighard served for 25 years as the Peach Rootstock Coordinator for the SAES-422 Multistate Project NC-140 "Improving Economic and Environmental Sustainability in Tree-Fruit Production through Changes in Rootstock Use", and was the Peach Section Chair for the International Society of Horticultural Science the past 8 years. He was also the co-convener for the ISHS 2018 HortCongress and is a Fellow of the American Society of Horticultural Science.

Dr. Guido Schnabel is a plant pathologist with research and extension responsibilities. He focuses on fungal diseases affecting the peach tree and fruit. His research over the last 20 years led to a better understanding of why important fungicides are losing their efficacy to control key diseases such as brown rot and anthracnose. He developed a horticultural technique (above ground root collar excavation) to reduce Armillaria root rot (oak root rot), which is now used in many commercial orchards to extend the productive life of trees on replant sites. He also studies causes and management practices of peach skin disorders. His MyIPM smartphone application provides fruit growers with disease and pest management information. The app is available free of charge in Google Play for Android phones and in the Apple Store for iPhones.

Dr. Ksenija Gasic is a peach breeder and geneticist. Clemson University revived peach breeding program after 25 years by hiring Dr. Gasic in 2008. Her research is focused on development of high quality, disease resistant peach varieties adapted to environmental conditions of the Southeastern U.S. She is developing early- to late-ripening, fresh market types of peaches and nectarines that meet the demands of consumers and provide the highest return on investment for growers. In addition to breeding varieties for the fresh market, Dr. Gasic is working on Armillaria root rot resistance in Prunus and development of new replant resilient rootstocks. Her program has been actively involved in development and application of modern technological tools in breeding programs (;

Dr. Juan Carlos Melgar, pomologist, joined Clemson University in August 2014. His research is focused on optimizing orchard nutritional management and improving water use efficiency. Dr. Melgar evaluates advanced selections and new varieties for their performance in SC in variety trials located in commercial orchards as well as at the Musser Farm, has recently started a project on the use of soil amendments to improve soil and tree health, and is also working on the use of horticultural practices that increase the value of peaches such as paper bags for both conventionally and organically grown peaches.

Dr. Libby Cieniewicz is a plant virologist working on ecology and epidemiology of plant viruses, with the ultimate goal of using this information to optimize virus disease management. In particular, areas of interest include how viruses are vectored by insects and how viruses evolve on a landscape scale. Libby directs the Southeastern Budwood Program of the National Clean Plant Network. The goal of this program is to ensure the availability of propagation material for nurseries, and ultimately planting material to the peach producers in the Southeast, that is virus-tested and of the highest quality. Blocks of commercially significant peach tree cultivars maintained on grower properties are indexed for the presence of Prunus necrotic ringspot, prune dwarf, and plum pox viruses each spring. Virus testing results are supplied to the major nurseries in Tennessee to ensure the budwood collected from these blocks for June budding is not infected with these viruses. In addition, the trees that produce seed of Guardian rootstock are indexed for the same viruses.

Dr. Douglas Bielenberg studies the interaction between plants and the abiotic environment. A major emphasis of his program has been investigating the molecular and genetic basis of dormancy behavior in peach. Bud chilling and heat requirement are major determinants of bloom time. Matching the chilling requirement of trees to our local climate is an important selection criteria used by breeders, and his program seeks to develop molecular markers for chilling requirement and bloom time traits that can be used in marker-assisted selection by the SC peach breeding program. He is also starting two projects to identify genetic markers for maximum fruit size potential in the breeding stock used by the SC breeding program, and to identify molecular markers for the dormancy status of floral buds that will assist in grower decision making for cultural practices that manipulate bud break timing.

Dr. Hehe Wang is a plant bacteriologist at Clemson University. She is conducting research to study the major bacterial diseases of peach in
South Carolina and surrounding states. Her research interests are to study the epidemiology, ecology, and genetics of the bacterial pathogens and develop novel, integrated, sustainable, and information-driven management strategies to reduce inoculum sources and prevent/minimize disease development.

Dr. Nathan Smith is an extension professor of Agribusiness Production and has 20 years of experience in production economics, farm management, marketing and farm policy. Dr. Smith works with multidisciplinary teams as part of his extension program conducting economic analyses on production research projects.  Since joining Clemson Dr. Smith has developed crop budgets and the crop comparison tools that are extensively used by extension agents, growers, and agricultural lenders.

Professors and tree fruit specialists from other universities but with a joint appointment at Clemson University are also part of the Peach Team.

  • Brett Blaauw is as an assistant professor and extension specialist for the University of Georgia and Clemson University. He joined the peach team in July 2016 as the regional peach entomologist for Georgia and South Carolina. The research in Dr. Blaauw's lab focuses on integrating insect behavior and ecology to more effectively and sustainably manage insect pests in Southeastern peach orchards.​ His program highlights the importance of IPM to manage key pests and to support of beneficial insects for increased sustainability. Currently, Dr. Blaauw’s lab is evaluating the spatio-temporal patterns of plum curculio and San Jose scale within peach orchards, which will lead to a better understanding of timing and location of insecticide applications. These projects will hopefully lead to  innovative tactics that exploit insect pest behavior and enhance biological control to reduce plum curculio and San Jose scale pressure in Southeastern peaches.
  • Wayne Mitchemis an Extension Associate at NC State University with weed management responsibilities in tree fruit crops. His position is funded cooperatively by NCSU, Clemson University, and the University of Georgia to conduct applied research, grower meetings, develop recommendations, and provide assistance to county agents, as well as fruit growers in NC, SC, and GA.

Several Cooperative Extension agents work together with these scientists to address South Carolina’s peach industry problems.

  • Andy Rollinsis the Horticultural Agent for the upstate of SC. He is specialized in commercial fruit and vegetable production and assists new growers with problem diagnosis and multiple decisions including soil testing/preparation, location/size of the planting, spray choices, calibration, and variety selection. Andy is actively involved in research projects with Clemson University as well as USDA-ARS specialists, and also does some new product testing.
  • Sarah Scott is a Horticulture Agent based out of Edgefield, SC. She serves Midlands area growers in commercial fruit and vegetable production which includes approximately 14,000 acres of peach orchards. She assists commercial growers in diagnosing problems, pest control, marketing and sustainability. Her work also includes helping homeowners and market gardeners with their gardens, landscapes, lawns and orchards. Sarah also assists in ongoing research that is done in peach orchards throughout the area.
  • Anthony (Tony) Meltonis the Horticulture Agent for the Pee Dee region of SC. He works with the production of all commercial and home turf, ornamentals, nuts, and fruits, and assists one large shipper, two small local growers/marketers, and many homeowners with the production of peaches.
  • Greg Henderson is a retired horticultural agent that collaborates with several members of the Peach Team on projects related to improving soil health, orchard soil management, and economics in Southeastern peach production systems.

Most of Clemson University’s interdisciplinary fruit research takes place at the 240-acre Musser Fruit Research Center.

  • Jeff Hopkins is the Musser Farm Manager. He manages the excellent farm staff and facility, and collaborates with other Peach Team members to make sure experiments are completed with excellence and precision. Furthermore, he oversees the production of Guardian® rootstock seed.