Joseph Roberts

Associate Professor of Turfgrass Pathology and Nematology
Extension Specialist
Horticulture Program Team, Plant and Environmental Sciences Department, PeeDee Research and Education Center

Office: Biosystems Research Complex, Room 206
Phone: 843-519-0492

Email: jar7@clemson.edu

Educational Background

Ph.D. Plant Pathology
North Carolina State University 2014

M.S. Plant Biology and Pathology
Rutgers University 2009

B.A. Chemistry
North Carolina State University 2007

B.S. Biological Sciences
North Carolina State University 2007

Profile

I am the state turfgrass pathologist for South Carolina with a faculty appointment of 70% Extension and 30% Research. My tenure home is within the Department of Plant and Environmental Sciences and I am located in the Biosystems Research Complex on Clemson Main Campus. My extension activities include organization and participation in educational programs offered as turfgrass research field days, regional and national organization conferences and trade shows, reports in trade publications and in online outlets, and diagnosis of disease and nematode issues in turfgrasses. Research in my program is centered on innovative strategies to limit turfgrass and crop loss from plant pathogens including fungi, bacteria, and nematodes. Fungal pathogens are prominent pests of many grass hosts, yet nematode and bacterial disease issues have increased in recent years, illustrating the need for research across the entire microbial community or “microbiome.” Our microbiome research is designed to understand both plant-microbe and microbe-microbe interactions. Improved understanding will enhance disease etiology, management recommendations, and possibly identify new beneficial microbes for enhancing turfgrass health. Research trials are performed yearly to examine cultural and chemical management of diseases commonly observed in the state and region.

Research Interests

Research in my program is centered on innovative strategies to limit turfgrass and crop loss from plant pathogens including fungi, bacteria, and nematodes. Fungal pathogens are prominent pests of many grass hosts, yet nematode and bacterial disease issues have increased in recent years, illustrating the need for research across the entire microbial community or “microbiome.” Our microbiome research is designed to understand both plant-microbe and microbe-microbe interactions. Improved understanding will enhance disease etiology, management recommendations, and possibly identify new beneficial microbes for enhancing pathogen resistance. Research trials are produced yearly to examine cultural chemical management of diseases commonly observed in the state and region.

Extension and Outreach

2022-24 – Clemson Pee Dee REC Turfgrass Research Field Day (Organizer and Presenter)
Objective: In-person educational sessions are held across a morning event in an effort to discuss and show turfgrass managers, distributors, and technical staff from companies various disease, insect, nematode, and weed activity on station within the turfgrass facility at PDREC.
Outputs: Turfgrass professionals attending engage with University scientists and students to discuss trial results that can be employed at local facilities. Trial results are easily visualized during the walking field tour and attendees receive a booklet highlighting results for recently competed trial work.

Publications

1. Doherty, J.R., Hutchens, W.J., Booth, J.C., McCall, D.S., Battaglia, M.V., DeBoer, E.J., and Roberts, J.A. 2024. Improving winter survival of interspecific hybrid bermudagrass in the Mid-Atlantic region through cultural practices. Crop, Forage, and Turfgrass Management 10(2):1-11. https://doi.org/10.1002/cft2.20303

2. Alam, M.S., Khanal, C., Roberts, J., Rutter, W, and Wadl, P. 2023. Enhancing reniform nematode management in sweet potato by complementing host-plant resistance with non-fumigant nematicides. Plant Dis. 108(7):2000-2005. https://doi.org/10.1094/PDIS-07-23-1412-RE.

3. Zeng, Y., Zhang, D., Giblin-Davis, R.M., and Roberts, J.A.a 2023. Ficophagus pisocarpae n. sp. (Nematoda: Aphelenchoididae), an associate of Ficus pisocarpa in China. Nematology 25(9): 965-978. https://doi.org/10.1163/15685411-bja10268.

4. Alam, M.S., Khanal, C., Roberts, J., and Rutter, W. 2023. Impact of non-fumigant nematicides on reproduction and pathogenicity of Meloidogyne enterolobii and disease
severity in tobacco. Journal of Nematology 55(1): 1-8. https://doi.org/10.2478/jofnem-2023-0025.

5. Zeng, Y., Zhang, D., Giblin-Davis, R.M., and Roberts, J.A. 2023. Ficophagus annulatae n. sp. (Nematoda: Aphelenchoididae), an associate of Ficus annulata in China. Nematology 0:1-14. https://doi.org/10.1163/15685411-bja10247

6. Zeng, Y., Dant, L., and Roberts, J.A. 2023. Ditylenchus dactylonae n. sp. (Nematoda: Anguinidae), as associate of Cynodon dactylon in the United States. Nematology . https://doi.org/10.1163/15685411-bja10240 (Impact - 1.38)

7. Doherty, J.R. and Roberts, J.A. 2023. Topdressing Biochar Compost Mixtures and Biological Control Organism Applications Suppress Foliar Pathogens in Creeping Bentgrass Fairway Turf. Plant Disease In Press: pp1-26. https://doi.org/10.1094/PDIS-07-22-1629-RE.

8. Alam, M.S., Khanal, C., Rutter, W., and Roberts, J. 2022. Non-fumigant nematicides are promising alternatives to fumigants for the management of Meloidogyne enterolobii in tobacco. Journal of Nematology 54(e2022-1):1-6. https://doi.org/10.2478/jofnem-2022-0045.

9. Zhao, C., Zhang, D., Zhao, X., Zeng, W., Zeng, Y., and Roberts, J.A. 2022. Ficophagus giblindavisi n. sp. (Nematoda: Aphelenchoididae), an associate of Ficus variegata in China. Nematology 24(8): 901-914. https://doi.org/10.1163/15685411-bja10178.

10. Zeng, Y., Chen, X., Ni, Y., Zhao, C., Kerns, J.P., Tredway, L.P., and Roberts, J.A. 2022. Morphological and Molecular Characterization of prevalent plant-parasitic nematodes from turfgrasses in Guangdong, China. Horticulturae 8(7): 1-23. https://doi.org/10.3390/horticulturae8070611.

11. Hutchens, W.J., Booth, J.C., Doherty, J.R., Roberts, J.A. , and D.S. McCall. 2022. Influence of post-application irrigation and soil surfactant on tebuconazole efficacy against spring dead spot. Crop Protection 156(6): 1-6. https://doi.org/10.1016/j.cropro.2022.105961.

12. Doherty, J.R. and J.A. Roberts. 2022. Investigating Chemical and Biological Control Applications for Pythium Root Rot Prevention and Impacts on Creeping Bentgrass Putting Green Rhizosphere Bacterial Communities. Plant Disease 106:641-647 https://doi.org/10.1094/PDIS-07-21-1505-RE.

13. Doherty, J.R., Crouch, J.A., and J.A. Roberts. 2021. Plant Age Influences Microbiome Communities More Than Plant Compartment in Greenhouse Grown Creeping Bentgrass. Phytobiomes J. 5(4):1-9. https://doi.org/10.1094/PBIOMES-03-21-0021-R.

14. Beckley, C.J. and J.A. Roberts. 2021. Utilizing organic amendments for general suppression of dollar spot on creeping bentgrass turf. Int. Turf Soc. Res. J. 1-16. https://doi.org/10.1002/its2.55.

15. Doherty, J.R., Crouch, J.A., and J.A. Roberts. 2020. Elucidating the influence of resident seed and soil microbiota on the developing creeping bentgrass microbiome. Agrosyst Geosci Environment. 2020:00-00. doi: https://doi.org/10.1002/agg2.20038.

16. Roberts, J.A., Ma, B., Tredway, L., Ritchie, D. and J. Kerns. 2017. Identification and pathogenicity of bacteria associated with etiolation and decline of creeping bentgrass golf course putting greens. Phytopathology 108:23-30. doi:10.1094/PHYTO-01-17-0015-R.

17. Doherty, J.R., M. Botti-Marino, J.P. Kerns, and J.A. Roberts. 2017. Response of phyllosphere associated microbial populations in creeping bentgrass to periodic fungicide applications. Plant Health Progress 18:44-49. doi:10.1094/PHP-RS-16-0067.

18. Crouch, J. Z. Carter, A. Ismaiel, and J.A. Roberts. 2017. The U.S. Mall microbiome: a census of rhizosphere bacteria inhabiting landscape turf. Crop Science 57: S341-S348. doi: 10.2135/cropsci2016.10.0849.

19. Roberts, J.A., D.F. Ritchie, and J.P. Kerns. 2016. Plant Growth Regulator Effects on Bacterial Etiolation of Creeping Bentgrass Putting Green Turf Caused by Acidovorax avenae. Plant Disease 100(3):577-582. doi:10.1094/PDIS-04-15-0419-RE.

20. Roberts, J.A., J.P. Kerns, and D.F. Ritchie. 2015. Bacterial etiolation of creeping bentgrass as influenced by biostimulants and trinexapac-ethyl. Crop Protection 72:119-126. doi:10.1016/j.cropro.2015.03.009.

21. Roberts, J.A. and D.F. Ritchie. 2014. Influence of antimicrobial compounds on bacterial etiolation of creeping bentgrass caused by Xanthomonas translucens. Appl. T. Science 11:1-8. doi:ATS-2014-047-RS.

22. Roberts, J.A. and J.A. Murphy. 2014. Anthracnose Disease on Annual Bluegrass as Affected by Foot Traffic and Sand Topdressing. Plant Dis. 98(10):1321-25. doi:10.1094/PDIS-08-13-0877-RE.

23. Roberts, J.A., L.P. Tredway, and D.F. Ritchie. 2014. First report of Xanthomonas translucens causing etiolation on creeping bentgrass turf in IL, KY, and NC. Plant Dis. 98(6):839. doi:10.1094/PDIS-05-13-0565-PDN.

24. Roberts, J.A., J.C. Inguagiato, and J.A. Murphy. 2013. A Method to Evenly Apply Foot Traffic to Turf Plots. Int. Turf Soc. Res. J. 12:743-746.

25. Inguagiato, J.C., J.A. Murphy, B.B. Clarke, and J.A. Roberts. 2013. Topdressing sand particle shade and incorporation effects anthracnose severity of an annual bluegrass putting green. Int. Turf Soc. Res. J. 12:127-134.

26. Roberts, J.A., B.B. Clarke, and J.A. Murphy. 2012. Lightweight Rolling Effects on Anthracnose of Annual Bluegrass Putting Greens. Agron. J. 104(4):1176-1181.

27. Roberts, J.A., J.C. Inguagiato, B.B. Clarke, and J.A. Murphy. 2011. Irrigation management effects on anthracnose of annual bluegrass putting greens. Crop Sci. 51(3):1244-1252.

28. Roberts, J.A., and L.P Tredway. 2008. First report of curvularia blight of zoysiagrass caused by Curvularia lunata in the United States. Plant Dis. 92(1):173.