Research Project: Development of Superior Hops and Resilient Hop Production Systems

Location: Forage Seed and Cereal Research Unit

Publications (Clicking on the reprint icon will take you to the publication reprint.)

Inoculum dose, diversity, dispersal, and damage: Simulating optimal economic control of hop powdery mildew at the landscape level - (Peer Reviewed Journal)
Pedro, J.F., Bhattacharyya, S., Chatterjee, S., Marsh, T.L., Hwang, J., Gent, D.H. 2026. Inoculum dose, diversity, dispersal, and damage: Simulating optimal economic control of hop powdery mildew at the landscape level. Agricultural Systems. 237. Article 104792. https://doi.org/10.1016/j.agsy.2026.104792.

Constructing hop powdery mildew management programs that mitigate potential technical barriers to trade in the European Union - (Peer Reviewed Journal)
Gent, D.H., Richardson, B.J., Massie, S.T. 2026. Constructing hop powdery mildew management programs that mitigate potential technical barriers to trade in the European Union. PhytoFrontiers. 6(3):660-668. https://doi.org/10.1094/PHYTOFR-11-25-0131-R.

Efficacy of fungicide modes of action for hop downy mildew: An individual participant data meta-analysis - (Peer Reviewed Journal)
Hwang, J., Gent, D.H. 2026. Efficacy of fungicide modes of action for hop downy mildew: An individual participant data meta-analysis. PhytoFrontiers. 6(3):650-659. https://doi.org/10.1094/PHYTOFR-11-25-0129-R.

Stability of hop yield and quality factors in response to delivery of irrigation and harvest timing - (Peer Reviewed Journal)
Gonzalez Tapia, F., Gent, D.H., Harper, S.J., Cowell, S.J., Jobe, C.A., Shellhammer, T.H., Ocamb, C.M., Richardson, B.J., Massie, S.T. 2026. Stability of hop yield and quality factors in response to delivery of irrigation and harvest timing. HortScience. 61(6):1273-1280. https://doi.org/10.21273/HORTSCI19367-26.

Late-season fungicide applications for hop powdery mildew have little effect on disease suppression and cone quality metrics in the cultivar Nugget - (Peer Reviewed Journal)
Gent, D.H., Richardson, B.J., Massie, S.T. 2026. Late-season fungicide applications for hop powdery mildew have little effect on disease suppression and cone quality metrics in the cultivar Nugget. Plant Health Progress. https://doi.org/10.1094/PHP-12-25-0270-BR.

Association mapping for hop cone chemistry and morphology identifies natural beneficial allele stacks - (Peer Reviewed Journal)
Clare, S.J., Schmuker, P., Altendorf, K.R. 2026. Association mapping for hop cone chemistry and morphology identifies natural beneficial allele stacks. The Plant Genome. 19(2). Article e70238. https://doi.org/10.1002/tpg2.70238.

Evaluation of fungicides for hop powdery mildew, study 1, Granger, Washington, 2025 - (Peer Reviewed Journal)
Massie, S.T., Richardson, B.J., Gent, D.H. 2026. Evaluation of fungicides for hop powdery mildew, study 1, Granger, Washington, 2025. Plant Health Progress. 27(2):346. https://doi.org/10.1094/PHP-11-25-0263-PDMR.

Evaluation of fungicides for hop powdery mildew, study 2, Granger, Washington, 2025 - (Peer Reviewed Journal)
Massie, S.T., Richardson, B.J., Gent, D.H. 2026. Evaluation of fungicides for hop powdery mildew, study 2, Granger, Washington, 2025. Plant Health Progress. 27(2):347. https://doi.org/10.1094/PHP-11-25-0264-PDMR.

Evaluation of fungicides for hop downy mildew, Hubbard, Oregon, 2025 - (Peer Reviewed Journal)
Massie, S.T., Richardson, B.J., Gent, D.H. 2026. Evaluation of fungicides for hop downy mildew, Hubbard, Oregon, 2025. Plant Health Progress. 27(2):345. https://doi.org/10.1094/PHP-11-25-0262-PDMR.

Automated detection and quantification of two-spotted spider mite life stages using computer vision for high-throughput in vitro assays - (Peer Reviewed Journal)
Wiseman, M.S., Woods, J.L., Hartgrave, C.R., Richardson, B.J., Gent, D.H. 2025. Automated detection and quantification of two-spotted spider mite life stages using computer vision for high-throughput in vitro assays. PLOS ONE. 20(12). Article e0333253. https://doi.org/10.1371/journal.pone.0333253.

How do growers respond to host resistance? A conditional Gaussian Bayesian network for causal inference of fungicide cost savings - (Peer Reviewed Journal)
Hwang, J., Bhattacharyya, S., Chatterjee, S., Marsh, T.L., Pedro, J.F., Gent, D.H. 2025. How do growers respond to host resistance? A conditional Gaussian Bayesian network for causal inference of fungicide cost savings. Phytopathology. 116(2):239-251. https://doi.org/10.1094/PHYTO-06-25-0199-R.

Pacific Northwest hop growers’ attitudes and perceptions toward sustainable agriculture: A mixed-methods study - (Peer Reviewed Journal)
Le, L., Gent, D.H., Johnson, J. 2026. Pacific Northwest hop growers’ attitudes and perceptions toward sustainable agriculture: A mixed-methods study. PhytoFrontiers. 6(1):117-128. https://doi.org/10.1094/PHYTOFR-06-25-0059-R.

Dynamic field assessment of canopy development and periderm maturation in potato (Solanum tuberosum L.) - (Peer Reviewed Journal)
Buckley, C.L., Gonzalez Tapia, F., Navarre, D.A., Blauer, J.M. 2025. Dynamic field assessment of canopy development and periderm maturation in potato (Solanum tuberosum L.). Plants. 14(17). Article 2780. https://doi.org/10.3390/plants14172780.

Genomic resources for Fusarium sambucinum, a causal agent of Fusarium canker of hop and dry rot of potato - (Peer Reviewed Journal)
Borland, T.G., Cauldron, N.C., Grünwald, N.J., Kronmiller, B., Thomas, W.J., Ocamb, C.M., Gent, D.H. 2025. Genomic resources for Fusarium sambucinum, a causal agent of Fusarium canker of hop and dry rot of potato. PhytoFrontiers. 5(4):714-717. https://doi.org/10.1094/PHYTOFR-05-25-0052-A.

Seven publicly available hop genotypes with multi-race powdery mildew resistance - (Peer Reviewed Journal)
Altendorf, K.R., Woods, P.O., Heineck, G.C., Richardson, B.J., Kenny, S., Gent, D.H. 2025. Seven publicly available hop genotypes with multi-race powdery mildew resistance. Journal of Plant Registrations. 19(3). Article e70035. https://doi.org/10.1002/plr2.70035.

Registration of ‘USDA-ARS Vera’: A new public hop cultivar with tropical, stone-fruit aroma and powdery mildew resistance - (Peer Reviewed Journal)
Altendorf, K.R., Gent, D.H., Reiter, M., Henning, J.A., Kenny, S. 2025. Registration of ‘USDA-ARS Vera’: A new public hop cultivar with tropical, stone-fruit aroma and powdery mildew resistance. Journal of Plant Registrations. 19(3). Article e70033. https://doi.org/10.1002/plr2.70033.

‘USDA EdleFrucht’: An early-harvest, high-yielding nobel-style hop cultivar - (Peer Reviewed Journal)
Henning, J.A., Townsend, M.S., Wiseman, M., Gent, D.H. 2025. ‘USDA EdleFrucht’: An early-harvest, high-yielding nobel-style hop cultivar. HortScience. 60(11):1900-1902. https://doi.org/10.21273/HORTSCI18482-25.

Development of a translation elongation factor 1-alpha (TEF) based TaqMan qPCR assay for Diaporthe humulicola, the causal agent of halo blight on hop - (Peer Reviewed Journal)
Hatlen, R., Szymanski, S.L., Adair, N.L., Fan, Q., Panwar, P., Sysak, R., Miles, L.A., Higgins, D.S., Rojas, J.A., Gent, D.H., Miles, T.D. 2025. Development of a translation elongation factor 1-alpha (TEF) based TaqMan qPCR assay for Diaporthe humulicola, the causal agent of halo blight on hop. Plant Disease. https://doi.org/10.1094/PDIS-11-24-2331-SR.

Sodium chlorite treatments in irrigation water are a significant source of chlorate and perchlorate in hop cones - (Peer Reviewed Journal)
Gonzalez Tapia, F., Walsh, D.B., Groenendale, D.P. 2025. Sodium chlorite treatments in irrigation water are a significant source of chlorate and perchlorate in hop cones. Journal of the American Society for Horticultural Science. 150(4):182-190. https://doi.org/10.21273/JASHS05493-25.

Fungicide selection, disease risk, and grower switching behavior - (Peer Reviewed Journal)
Hwang, J., Bhattacharyya, S., Chatterjee, S., Marsh, T.L., Pedro, J.F., Gent, D.H. 2025. Fungicide selection, disease risk, and grower switching behavior. Plant Disease. https://doi.org/10.1094/PDIS-01-25-0044-RE.

The diversity and determinants of fungicide programs for hop powdery mildew - (Peer Reviewed Journal)
Hwang, J., Bhattacharyya, S., Chatterjee, S., Marsh, T.L., Pedro, J.F., Gent, D.H. 2025. The diversity and determinants of fungicide programs for hop powdery mildew. Plant Disease. https://doi.org/10.1094/PDIS-01-25-0043-RE.

Effect of imidacloprid application timing on twospotted spider mite (Acari: Tetranychidae) on hop - (Peer Reviewed Journal)
Woods, J.L., Richardson, B.J., Kaur, N., Dorman, S.J., Gent, D.H. 2025. Effect of imidacloprid application timing on twospotted spider mite (Acari: Tetranychidae) on hop. Journal of Economic Entomology. 118(3):1441-1445. https://doi.org/10.1093/jee/toaf079.

Hop diseases: Characteristics and management - (Book / Chapter)
Radisek, S., Gent, D.H., Miles, T.D., Harper, S.J., Jakse, J., Zasada, I.A. 2026. Hop diseases: Characteristics and management. In: Carbone, K., editor. All About Hops: The Crop, its Cultivation, and its Uses in Brewing and Beyond. 1st edition. Cham, Switzerland: Springer. p. 121-194.

Predictive ability of hop (Humulus lupulus L.) grown in single hills on plot environments - (Peer Reviewed Journal)
Altendorf, K.R., Heineck, G.C., Tawril, A. 2025. Predictive ability of hop (Humulus lupulus L.) grown in single hills on plot environments. Crop Science. 65(2). Article e70024. https://doi.org/10.1002/csc2.70024.

Late-season irrigation lapses impact the physiology, yield, and metabolite production of Yakima Valley hops - (Peer Reviewed Journal)
Gonzalez Tapia, F. 2025. Late-season irrigation lapses impact the physiology, yield, and metabolite production of Yakima Valley hops. Journal of the American Society for Horticultural Science. 150(3):136-146. https://doi.org/10.21273/JASHS05461-24.

A modified disease risk index for hop powdery mildew - (Peer Reviewed Journal)
Gent, D.H., Richardson, B.J., Massie, S.T. 2025. A modified disease risk index for hop powdery mildew. PhytoFrontiers. 5(1):30-41. https://doi.org/10.1094/PHYTOFR-10-24-0117-R.

What explains hop growers’ fungicide use intensity and management costs in response to powdery mildew? - (Peer Reviewed Journal)
Hwang, J., Bhattacharyya, S., Chatterjee, S., Marsh, T.L., Pedro, J.F., Gent, D.H. 2024. What explains hop growers’ fungicide use intensity and management costs in response to powdery mildew? American Phytopathology Society. 114(10):2287-2299. https://doi.org/10.1094/PHYTO-04-24-0127-R.

Yellow dwarf virus resistance in barley: Phenotyping, remote imagery, and virus-vector characterization - (Peer Reviewed Journal)
Massman, C., Rivedal, H.M., Dorman, S.J., Tanner, K.C., Frederickson, C., Temple, T.N., Fisk, S., Helgerson, L., Hayes, P. 2024. Yellow dwarf virus resistance in barley: Phenotyping, remote imagery, and virus-vector characterization. Phytopathology. 114(9):2084-2095. https://doi.org/10.1094/PHYTO-10-23-0394-KC.

Identifying highly connected sites for risk-based surveillance and control of cucurbit downy mildew in the eastern United States - (Peer Reviewed Journal)
Ojwang, A.M., Lloyd, A.L., Bhattacharyya, S., Chatterjee, S., Gent, D.H., Ojiambo, P.S. 2024. Identifying highly connected sites for risk-based surveillance and control of cucurbit downy mildew in the eastern United States. PeerJ. https://doi.org/10.7717/peerj.17649.

Detection of Podosphaera macularis in air samples by quantitative PCR - (Peer Reviewed Journal)
Gent, D.H., Adair, N.L., Hatlen, R., Miles, T.D., Richardson, B.J., Rivedal, H.M., Ross, C., Wiseman, M.S. 2024. Detection of Podosphaera macularis in air samples by quantitative PCR. Plant Disease. https://doi.org/10.1094/PDIS-04-24-0894-RE.

Free-riding in plant health: A social-ecological systems approach to collective action - (Peer Reviewed Journal)
Garcia-Figuera, S., Lowder, S.R., Lubell, M.N., Mahaffee, W.F., McRoberts, N., Gent, D.H. 2024. Free-riding in plant health: A social-ecological systems approach to collective action. Annual Review of Phytopathology. 62:4.1-4.28. https://doi.org/10.1146/annurev-phyto-121423-041950.

Suppression of hop downy mildew as influenced by the timing of selected fungicides - (Peer Reviewed Journal)
Richardson, B.J., Gent, D.H. 2024. Suppression of hop downy mildew as influenced by the timing of selected fungicides. Plant Health Progress. https://doi.org/10.1094/PHP-10-23-0086-BR.