PhD, Washington State University
2016 - Received Award for Achievements in Plant Disease Management on Pulse Crops from the Canadian Phytopathological Society
2014 - Received Award for Achievements in Plant Disease Management Award on Clubroot Risk Mitigation from the Canadian Phytopathological Society
2011 - Received the most prestigious Outstanding Research Scientist Award from Canadian Phytopathological Society
2011 - Received Silver Teamwork Recognition Award 2011 (Canola Clubroot Risk Mitigation Team) from Alberta Agriculture
2010 - Received the Gold award under the Premier’s Award of Excellence Program as a member of Alberta Agriculture’s Rhodiola Rosea Commercialization Project to provide my expertise in plant pathology.
2010 - Received the Canada Awards for Excellence - Certificate of Merit as a member of Alberta Agriculture’s Rhodiola Rosea Commercialization Project to provide my expertise in plant pathology.
Major Responsibilities/Research Interests
At present, my research focuses primarily on investigating the etiology and biology of important diseases of canola. Clubroot has presented a difficult challenge and I was particularly proud to read a quote by Dr. G. Dixon, one of the world’s foremost clubroot researchers, “Canada is now the world powerhouse for clubroot research and management”. Areas of research include suppression of inoculum in fields, assessment of spore survival, studies on the effects of management practices on pathotype composition, trials on pesticide efficacy and application technique, resistance screening and soil amendment technology. We are also developing a yield loss model to provide a practical and economically relevant understanding of the impact of clubroot severity on yields and to distinguish among resistant, moderately resistant and susceptible genotypes of canola. Work is ongoing to develop DNA primers to identify pathotypes of P. brassicae and quantify resting spores.
Other research interests include studies of the re-emergent blackleg issue. This disease has become a threat both to canola production and its export, since barriers to trade can and have been erected based on infectivity of contaminated seed. My work has emphasized an integrated approach to blackleg management, combining the deployment of genetically resistant canola hybrids with proper rotations and other tools, such as foliar fungicides to control L. maculans. I am interested in investigating the sensitivity of the isolates of L. maculans collected in Alberta over the past decade to the fungicide pyraclostrobin, a strobilurin that is commonly applied as a foliar and seed treatment for blackleg. I am very pleased to see my published blackleg yield loss model has been frequently cited in scientific papers and used in and industry meetings.
Verticillium stripe is a potential threat to canola production in Canada, because of its persistence in the soil and rapid spread on farm equipment and contaminated seed. The disease has resulted in devastating crop losses in Europe. I am very happy that our group published the first report on verticillium wilt of canola, which has received attention from the canola industry. I am leading research to determine the potential for yield losses, determine the effects of critical host-pathogen interactions, such as the stage at which infection occurs, and evaluate host genotypes for resistance or tolerance to Verticillium stripe.
A smaller portion of my work involves developing management practices for diseases of pulse and specialty crops. Currently, I am cooperating with scientists from Agriculture and Agri-Food Canada to identify management strategies for Aphanomyces root rot of field pea, a disease that is particularly difficult to control. No resistant cultivars are available, seed treatments do not provide full-season protection, and there are no in-crop fungicide products. I have focused on identifying markers associated with Aphanomyces resistance and development of yield loss models to measure the efficacy and economic benefits of control methods.
Potential graduate students with an interest in applied plant pathology are encouraged to contact me directly to discuss possible opportunities in my program.
Dr. Rudolph Fredua-Agyeman (Research Associate)
Longfei Wu (PhD student)
Ji Cui (MSc Student)
Becky Yixiao Wang (Technician)
Ronald Nyandoro (Technician)
Luis Dongxiao Hou (Technician)
Diseases of Canola Crop Research Papers:
Fraser M., S.E. Strelkov, G.D. Turnbull, H.U. Ahmed, W. Barton, and S.F. Hwang*. 2019. Evaluation of pyraclostrobin as a seed and foliar fungicide for management of blackleg (Leptosphaeria maculans) of canola (Brassica napus). Can. J. Plant Sci. (accepted)
Hwang, S.F., H.U. Ahmed, Q. Zhou, H. Fu, G.D. Turnbull, R. Fredua-Agyeman, S.E. Strelkov, B.D. Gossen and G. Peng. 2019. Influence of resistant cultivars and crop intervals on clubroot of canola. Can. J. Plant Sci. https://doi.org/101139/CJPS-2019-0018
Ernst, T.W., K. Swaroop, D. Stanton, D.C. Rennie, S. F. Hwang, and S.E. Strelkov. 2019. Plasmodiophora brassicae Resting Spore Dynamics in Clubroot Resistant Canola (Brassica napus) Cropping Systems. Plant Pathology 68: 399-408. https://doi.org/10.1111/ppa.12949
Fredua-Agyeman R., S.F. Hwang, S.E. Strelkov, Q. Zhou, V.P. Manolii and D. Feindel. 2018. Germplasm screening and identification of Brassica accessions resistant to ‘old’ and ‘new’ pathotypes of Plasmodiophora brassicae in Alberta, Canada. Plant Pathology https://doi.org/10.1111/ppa.12980
Zhou, Q., S.F. Hwang*, S.E. Strelkov, R. Fredua-Agyeman and V.P. Manolii. 2018. A molecular marker for specific detection of new pathotype 5-like strains of Plasmodiophora brassicae in canola. Plant Pathology 67:1582-1588. https://doi.org/10.1111/ppa.12868
Strelkov, S.E., S.F. Hwang, V.P. Manolii, R. Fredua-Agyeman, M.W. Harding, G. Peng, B.D. Gossen, M.R. McDonald and D. Feindel. 2018. Virulence and pathotype classification of Plasmodiophora brassicae populations collected from clubroot resistant canola Brassica napus in Canada. Can. J. Plant Pathol. 40(2): 284-298. https://doi.org/10.1080/07060661.2018.1459851
Holtz, M., S.F. Hwang and S.E. Strelkov. 2018. Genotyping of Plasmodiophora brassicae reveals the presence of distinct populations. BMC Genomics 19: 254-264. https://doi.org/10.1186/s12864-018-4658-1
Fredua-Agyeman R., S.F. Hwang, S.E. Strelkov, Q. Zhou and D. Feindel. 2018. Potential loss of clubroot resistance genes from donor parent Brassica rapa subsp. rapifera (ECD 04) during doubled haploid production. Plant Pathology 67: 892-901. Doi:10.1111/ppa.12816
Hwang, S.F., H.U. Ahmed, Q. Zhou, H. Fu, R. Fredua-Agyeman, G.D. Turnbull and S.E. Strelkov. 2017. First report of Verticillium dahlaiae Kleb. causing Verticiillium wilt of canola (Brassica napus L.) in Alberta, Canada . Can. J. Plant Pathol. 39(4): 514-526. Doi:10.1080/07060661.2017.1375996
Hwang, S.F., H.U. Ahmed, S.E. Strelkov, Q. Zhou, B.D. Gossen, M.R. McDonald, G. Peng, and G.D. Turnbull. 2017. Suppression of clubroot by dazomet fumigant. Can. J. Plant Sci. 98: 1-11. https://doi.org/101139/CJPS-2017-0099
Hwang, S.F., H.U. Ahmed, S.E. Strelkov, Q. Zhou, G.D. Turnbull, and B.D. Gossen. 2018. Effects of land preparation on the efficacy of Vapam to control clubroot (Plasmodiophora brassicae) and seedling blight of canola. European Journal of Plant Pathology 150:341-349. Doi: 10.1007/s10658-017-1281-y
Hwang, S.F., S.E. Strelkov, H.U. Ahmed, V.P. Manolii, Q. Zhou, H. Fu, G.D. Turnbull, R. Fredua-Agyeman and D. Feindel. 2017. Virulence and inoculum density-dependent interactions of CR canola with Plasmodiophora brassicae Woronin in Alberta. Plant Pathology 66: 1318-1328. Doi: 10.1111/ppa.12688.
Fraser M., S.F. Hwang, H.U. Ahmed, A. Akhavan, G. Stammler, W. Barton, and S.E. Strelkov. 2017. Sensitivity of Leptosphaeria maculans to pyraclostrobin 1 in Alberta, Canada. Can. J. Plant Sci. 97 (1): 83-91.
Hwang, S.F., S.E. Strelkov, G. Peng, H.U. Ahmed, Q. Zhou and G.D. Turnbull. 2016. Blackleg (Leptosphaeria maculans) severity and yield loss in canola in Alberta, Canada. Plants 5,31; doi:10.3390/plants5030031
Strelkov, S.E., S.F. Hwang, V.P. Manolii, T. Cao and D. Feindel. 2016. Emergence of new virulence phenotypes of Plamdiophora brassicae on canola (Brassica napus) in Alberta, Canada. European Journal of Plant Pathology 145: 517-529. Doi: 10.1007/s10658-016-0888-8.
Rennie, D.C., M.D. Holtz, T.K. Turkington, S.F. Hwang, and S.E. Srelkov. 2015. Movement of Plasmodiophora brassicae resting spores in windblown dust. Can. J. Plant Pathol. 37(2): 188-196. http://dx.doi.org/10.1080/07060661.2015.1036362
Hwang, S.F., H.U. Ahmed, G.D. Turnbull, B.D. Gossen, and S.E. Strelkov. 2015. Effect of seeding date and depth, seed size and fungicide treatment on Fusarium and Pythium seedling blight of canola. Can. J. plant Sci. 95(2): 293-301, 10.4141/cjps-2014-268.
Hwang, S.F., H.U. Ahmed, Q. Zhou, G.D. Turnbull, S.E. Strelkov and B.D. Gossen. 2015. Effect of host and non-host crops on Plasmodiophora brassicae resting spore concentrations in soil and potting mixtures. Plant Pathology 64: 1198-1206. http://Doi: 10.1111/ppa.12347
Diseases of Pulse Crops Research Papers:
Nyandoro, R., K.F. Chang, S.F. Hwang*, H.U. Ahmed, G.D. Turnbull and S.E. Strelkov. 2019. Management of Root Rot of Soybean in Alberta with Fungicide Seed Treatments and Genetic Resistance. Can. J. Plant Sci. 99: 499-509. http://www.nrcresearchpress.com/doi/abs/10.1139/CJPS-2018-0266
Chang, K.F., S.F. Hwang*, R.L. Conner, H.U. Ahmed, Q. Zhou, H. Fu, G.D. Turnbull, N. Nyandoro, S.E. Strelkov, D.L. McLaren and B. D. Gossen. 2019. Effects of Fusarium avenaceum and Rhizoctonia solani on growth of soybean in saline soils. Can. J. Plant Sci. http://www.nrcresearchpress.com/doi/abs/10.1139/CJPS-2017-0371
Wu, L.F., K.F. Chang, S.F. Hwang*, R.L. Conner, R. Fredua-Agyeman, D. Feindel and S. E. Strelkov*. 2019. Evaluation of host resistance and fungicide application as tools for the management of root rot of field pea caused by Aphanomyces euteiches. The Crop Journal 7: 38-48. doi:10.1016/j.cj.2018.07.005
Li, N., Q. Zhou, K.F. Chang, H. Yu, S.F. Hwang, R.L. Conner, S.E. Strelkov, D.L. McLaren and G.D. Turnbull. 2019. Occurrence, pathogenicity and species identification of Pythium causing root rot of soybean in Alberta and Manitoba, Canada. Crop Protection 118: 36-43. https://doi.org/10.1016/j.cropro.2018.12.009
Wu, L.F., K.F. Chang, R.L. Conner, S.E. Strelkov, R. Fredua-Agyeman, S.F. Hwang*, and D. Feindel. 2018. Aphanomyces euteiches: A Threat to Canadian Field Pea Production. Engineering 4: 542-551.
Zhou, Q. N. Li, R. Nyandoro, K.F. Chang, S.F. Hwang*, S.E. Strelkov, R.L. Conner, D.L. McLaren, H. Fu, M.W. Harding and G.D. Turnbull. 2018. Genetic diversity and aggressiveness of Fusarium species isolated from soybean in Alberta, Canada. Crop Protection 105: 49-58.
Chang, K.F., S.F. Hwang, H.U. Ahmed, S.E. Strelkov, M.W. Harding, R.L. Conner, D.L. McLaren, B. D. Gossen and G.D. Turnbull. 2018. Disease reaction to Rhizoctonia solani and yield losses in soybean. Can. J. Plant Sci. 98: 115-124. https://dx.doi.org/10.1139/CJPS-2017-0053
Chang, K.F., S.F. Hwang, H.U. Ahmed, H. Fu, Q. Zhou, S.E. Strelkov and G.D. Turnbull. 2017. First report of Phytophthora sansomeana causing root rot in field pea in Alberta, Canada. Crop Protection 101: 1-4. http://dx/doi.org/10.1016/cropro.2017.07.008
Chang, K.F., S.F. Hwang, H.U. Ahmed, Q. Zhou, S.E. Strelkov, R.L. Conner, , D.L. McLaren, M. A. Henriquez, M. W. Harding and G.D. Turnbull. 2017. First report of Phytophthora sojae causing root rot in soybean (Glycine max L.) in Alberta, Canada. Crop Protection 91: 49-56.
Chang, K.F., S.F. Hwang, R.L. Conner, H.U. Ahmed, Q. Zhou, S.E. Strelkov, D.L. McLaren and B.D. Gossen and G.D. Turnbull. 2015. First report of Fusarium proliferatum causing root rot in soybean (Glycine max L.) in Canada. Crop Protection 67: 52-58.
Integrated agronomic, mechanical, biological, and chemical control of insects, disease organisms, and weeds that interfere with field crop and horticultural crop production. Not to be taken if credit received for PL SC 495. Prerequisites: ENT 222, PL SC 352, and PL SC 380; one course may be taken as a corequisite, or consent of the instructor.Winter Term 2021
Integrated agronomic, mechanical, biological, and chemical control of insects, disease organisms and weeds that interfere with field crop and horticultural crop production. Prerequisites: ENT 222, PL SC 352, and PL SC 380; one course may be taken as a corequisite.Winter Term 2021