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1890 Faculty Research Sabbatical Program
2023 Awardees


Emmanuel Asiamah, Ph.D.

Assistant Professor of Animal Science
Department of Agriculture
University of Arkansas at Pine Bluff

ARS Research Partner

Joan Burke, Ph.D.
Research Animal Scientist
Dale Bumpers Small Farms Research Center

Diseases caused by opportunistic environmental parasites and pathogens are significant constraints to optimum animal production. Parasitic and infectious diseases pose a serious threat to livestock farmers, especially sheep and goat keepers. Most animal diseases are caused by bacteria (gram-positive and gram-negative), viruses, protozoa, and internal parasites such as gastrointestinal nematodes (GIN). Current control programs based on anthelmintics and antimicrobial administration fail due to their reduced effectiveness and resistance in animals (Oliver, Murinda, and Jayarao, 2011). Due to the shortcomings of the traditional methods for controlling diseases, new avenues are being pursued. Food safety, animal welfare, and public health concerns have fueled the interest in plant-based alternatives for disease prevention and treatment. The discovery of the potential anthelmintic and antimicrobial properties of secondary plant compounds, including condensed tannins, has prompted numerous research into the various tannin-rich forages.

Tannin-rich forages like sericea lespedeza (SL; Lespedeza cuneata), sainfoin (Onobrychis viciifolia), and sulla (Hedysarum coronarium) have been reported to show anthelmintic activities against GIN in sheep and goats ( Lange et al., 2006; Shaik et al., 2006; Terrill et al., 2009). Cranberry is another plant with an anthelmintic potency due to its abundance of condensed tannins. A recent study revealed anthelmintic activity against GIN in lambs supplemented with cranberry vine(CV) pellets (Chalut et al., 2019).

Tannin-rich plants may possess some systemic benefits to the animals beyond their anthelmintic activities. Current scientific literature has shown that aqueous extracts of SL can trigger immune responses by activating genes involved in the Wingless (Wnt) signaling and Toll -like receptor( TLR) pathways in goats (Asiamah et al. 2016). Also, cranberry has been shown to support mammalian urinary tract health through its bacterial anti-adhesion activity (Howell et al., 2005). These discoveries warrant further research into the systemic effects of tannin-rich forages beyond just their potential anthelmintic activity in livestock. Tannin-rich forages may provide a natural alternative to combat GIN and systemically modulate genes involved in ruminants' key innate immune response pathways.

The proposed research is structured to generate data on the potential immunomodulatory and anthelmintic activities of CVP and SL in sheep. The broad objective of the proposed study is to investigate the effect of daily supplementation of CVP and SL on overall sheep health and performance.

The aim is to provide the farmer with a cost-effective, eco-friendly means to help reduce, if not prevent, the incidence of disease in their herd. This project will broadly contribute to efforts to make livestock production safer and more sustainable.

Dr. Emmanuel K. Asiamah is an Assistant professor of Animal Science in the Department of Agriculture at the University of Arkansas at Pine Bluff. He teaches undergraduate and graduate courses related to livestock production, poultry production, animal physiology/biotechnology, physiology of reproduction, and quality assurance of meat. Dr. Asiamah’s research is focused on the health and production efficiency of livestock, which can be applicable to small and mid-size farms. His current research work involves finding alternative ways to improve the immune system of animals in order for them to be able to mount their own defense against diseases with little or no drug administration. Dr. Asiamah earned his Master’s degree in Integrated Animal Health Systems and his Ph.D. degree in Applied Science and Technology from North Carolina A&T State University.


Sathish Ponniah, Ph.D.

Associate Professor
Department of Agriculture
University of Arkansas at Pine Bluff

ARS Research Partner

Yulin Jia, Ph.D.
Research Plant Pathologist
Dale Bumpers National Rice Research Center

Rice blast caused by Magnaporthe oryzae is the most devastating diseases of rice and poses a serious threat to world food security (Wu et al. 2015). The fungus colonizes leaves (leaf blast), panicles (panicle blast) and other parts of the rice plants and causes huge crop loss in rice growing areas (Ashkani et al. 2015). Blast is responsible for 30% of losses in global rice production, the equivalent of feeding 60 million people (Pennisi, 2010). The United States annually produces 1.6% of the World's rice; however, the use of fungicides to manage blast and other fungal diseases has very costly. The cost of fungicides to control rice blast and other rice fungal diseases was estimated to be around $65 million (Nalley et al. 2016). Resistance with major resistance genes have been effectively used to control blast. However, rice cultivars containing only a single R gene to a specific pathogen race often become susceptible over time due to the emergence of new virulent races. Weedy rice coexists with rice since the beginning of rice cultivation and eventually has evolved novel resistance mechanisms to rice blast (Jia and Gealy 2018. Goad et al. 2020). One of the novel approaches is to stack a new resistance (R) gene from weedy rice into cultivated rice. The Ptr gene in rice isolated from US rice variety Katy encodes a protein with 4 armadillo repeats and confers a broad spectrum of blast resistance except for race IB33. This year, an allele of PtrBHA resistant to IB33 was identified in a US weedy rice genotype. These findings demonstrate that there exist novel resistance responses weedy rice. The objective of this study is to identify more resistance genes from different weedy rice and to determine if there exists an avirulence gene for PtrBHA, additional plant components involved in disease resistance and a tradeoff between disease resistance and productivity.

Dr. Sathish Ponniah is an Associate Professor in the Department of Agriculture with twelve years of experience in rice and sweetpotato research and leading the sweetpotato foundation seed program at the University of Arkansas at Pine Bluff. He is using the gene-editing approach in developing high-yielding varieties in rice. He has gained around 2 million dollars of grant money for research and extension programs. Dr. Ponniah has published in several peer-reviewed journals and serves as a major advisor for six graduate students.


Gregory Bernard, Ph.D.

Assistant Professor of Plant Sciences
Department of Agricultural and
Environmental Sciences
Tuskegee University

ARS Research Partner

Elizabeth Ainsworth, Ph.D.
Research Molecular Biologist
Global Change and Photosynthesis Research


Agriculture is facing a number of grand challenges, including climate change (Bailey-Serres et al., 2019), sustainability (Springmann et al., 2018), tightening labor markers (Zahniser et al., 2018), and declining export markets for some crops (Melhim, 2022). Implementing autonomous tools can help farmers address increasing labor and input costs and greater competition from imported produce. Such technologies may also reduce the environmental footprint of agriculture by decreasing carbon emissions and chemical use. Adopting current and emerging autonomous tools leveraging new cost-effective labor-management strategies with innovations in precision farming protocols is becoming increasingly important for small-scale farms to remain viable in the future (Lowenberg-DeBoer et al., 2022). Autonomous tools can also help address the phenotyping bottleneck in crop improvement (Harfouche et al., 2019).

Crop phenotyping applies a wide variety of sensors and diagnostic tools to select genotypes that are well-adapted to different environments and to understand crop responses to environmental conditions (Furbank and Tester, 2011). The information collected from phenotypic analyses can be used to improve crop production through overall health assessments and predictive modeling. Plant health diagnostics is advanced by high-throughput plant phenotyping, which employs autonomous robots, including drones and field rovers, for data collection leveraged by machine learning and AI-assisted analytics (Ninomiya, 2022). Aerial and terrestrial-monitoring are beneficial for crops with differences in canopy structure, and together can provide a comprehensive view of crop dynamics (Rufo et al., 2021). Spectral imaging involves the detection of light reflected by plants. Crop surface models measuring plant parameters, including plant height, chlorophyll content, NDVI (normalized difference vegetation index), and overall growth, may be developed by aerial spectral imagery of multispectral and hyperspectral data. Hyperspectral imaging can also be used to infer the physiological status of plants (Fu et al., 2020).

The aim of this project is to test aerial and ground-based high throughput phenotyping tools for detection of crop health. The target crop is sweet potato (Ipomoea batatas), an important U.S. crop that grew in production between 2007 and 2017, but then suffered from Hurricane Florence and global competition for exports (Melhim, 2022). U.S. market share of global sweet potato trade has fallen from 72% in 2018 to 45% in 2021 (USDA-GATS). Sweet potato yields have remained stagnant for over a decade, and there is clear need for research efforts to improve and climate-proof production (Melhim, 2022). The proposed research aims to take advantage of field facilities in Urbana, IL where crops can be exposed to climate change conditions (e.g., elevated ozone concentrations, low soil moisture or high temperatures) that alter leaf and canopy properties in order to test and develop phenotyping techniques to monitor the health and productivity of sweet potato. These tools can then be taken back to Tuskegee University and used in pre-breeding programs.

Dr. Gregory C. Bernard is an Assistant Professor of Plant Sciences at Tuskegee University. Dr. Bernard specializes in molecular plant pathology, nanobiotechnology, biopesticide development, integrating autonomous tools for crop phenotyping, and identifying plant responses to magnetic fields.