Brief Summary of Minutes of Annual Meeting

• Documented the prevalence (and diversity) of PVY strains in potato in Columbia Basin and the role of strain-specific resistance in the selection of PVY recombinants
• Determined that potato mop-top virus (PMTV) is highly conserved among isolates collected in US potato production regions.
• Surveillance of viruses PMTV, TRV and PVY in seedlots lot throughout the US and imported from Canada.
• Surveillance for subterranean, vector of PMTV.
• Quantified stubby root nematode composition in soils collected from 8 different states. Develop detection and identification protocols from soils using PCR and barcoding.
• Developed conventional PCR protocol specific for allius.
• Developed realtime PCR protocol for quantifying nematodes using TaqMan probe and SYBR green assay. Currently, developing a multiplex real-time PCR for four different stubby root nematodes found in the eight states across the country.
• Demonstration of potential for hyperspectral spectroscopy for the evaluation of seed lots for PVY infection.

Enhancements to virus diagnostics:

• For dormant tuber testing, found that most of the virus is in the skin, as opposed to tuber flesh.
• FTA card work – can press tuber skin samples onto an FTA card. Multiple assays can then be run on the nucleic acids on small punches of each card. Assays have worked well for RT-PCR for PVY, PVS, PVX, PVA, PLRV, TRV, PMTV, as well as an RNA control (EF1alpha). The FTA card can be frozen and stored for months or perhaps even years.
• Development of an immunocapture RT-PCR assay for PMTV.
• Development of an assay to detect subterranea, the vector of PMTV, from soil and peat moss.

Aphid capture data have been compiled from the North Central Regional, Aphid Suction Trap Network (http://traps.ncipmc.org/) from a span of 10 years (2005-2015) and 45 locations comprising over 180 species of aphids and nearly 1M individual captures in the upper Midwestern US. The flight phenology of the principle PVY-vector species of aphids has been modeled.  This has affected the management recommendations: build programs of control around timing of principle vector flights (early grain aphid migration, etc).

Additional aphid trapping data from various potato producing states are being identified to species and are planned for validation in the current models. These trap data will be standardized against cumulative growing degree-days (base50) using random effects models, and these will be used to predict the dispersal phenology of unique aphid species in different states. Next steps are additional aphid identification requirement (state-specific), fitting aphid phenology from other states (underway for year 1 ID’s), identification of the predominate species associated with the greatest PVY movement, and seasonality of vector prevalence- modeling landscape risk. 

Annual abundance of non-colonizing aphid species and PVY incidence in ME. 

Primary accomplishments is that ME can now forecast the initial yearly occurrence of aphid vectors and know there is consistent late season aphid pressure, as well as PVY increase later in season which can help with management practices.

Relationship of wild hosts to PVY incidence.  Major accomplishments: Determining that non-crop vegetation (with the likely exception of plants in the family Solanaceae) does not serve as an important reservoir of PVY.  Also, he is obtaining evidence that the notion of PVY’s broad host range needs to be re-evaluated, and confirmed that infected potato tubers are the most important source of initial inoculum (not really coming from outside of the field). 

Used the potato SNP array to create high quality potato populations to conduct genetic mapping of virus resistance traits.

For PMTV, SNPS associated with resistance appear to be located in chromosomes 2 and 9.

Continued development and study of Castle Russet which has resistance to TRV and PVY (i.e. it carries Rysto gene). Long term management of virus may start to incorporate Castle Russet.

Sixty potato cultivars representing every market class were tested for their sensitivity to PMTV- and TRV-induced tuber necrosis in field trials conducted in 2015 and 2016. Expression of tuber necrosis by each virus was variable among cultivars with a number of them identified as being insensitive to the tuber necrosis phase caused by each virus. The commercial potato industry has cultivars available within each market class that can be used to escape economic loss by utilizing potato varieties that do not express tuber necrosis.

Characterized PVY symptoms of potato varieties in the greenhouse and field. This has shown that recombinant strains have mild symptoms, making visual inspections difficult.

Documented the effect of virus infection on tuber quality and storage attributes. Current season PVY infections have not caused a degradation of processing quality, suggesting that initial concerns were not justified (unless initial concerns were due to a different, undetected virus infection).  Industry concerns about PVY and degraded fry processing quality have not been verified. 

Similarly, we have demonstrated that symptomatic tubers don’t seem to cause fry defect issues. Tubers are testing positive, but not causing issue at processing. 

Collected data to compare winter grow out testing to PVY detection from dormant tubers using RT-PCR. Conducted a tuber testing workshop for participants in 4-state study. 

A potato seed PVY-risk calculator has been developed and is currently being tested (<msuextension.org/econtools/pvy_calc/index.html>). For Russet Norkotah and Russet Burbank potatoes, you can enter assumed level of the virus and the calculator should predict revenue loss per acre, total revenue loss, and adjusted seed price.  From the webpage, this “Calculator estimates end-of season loss from PVY for a grower selling to either process or fresh marker depending upon beginning of season PVY incidence.”  This tool will tell a grower how much you should pay for the seed to be economically unharmed. 

Potato seed certification inspector training was held in 2016 at the Othello, WA (WSU experiment station) with 43 varieties infected with 3 PVY strains.  PVY demo plots made the industry aware of the difficulties in removing PVY from seed lots. This demonstration plot will be established in WA, WI, and ME in 2018.

Alyokhin, A. 2015.  Preventing the Spread of Potato Viruses: What Insecticides Can and Cannot Do. Webinar presented for the Pest Management Network, available at http://www.plantmanagementnetwork.org/edcenter/seminars/potato/PotatoViruses/

Alyokhin, A. 2015. Managing non-persistently transmitted aphid-borne viruses: Perceptions and reality. Symposium “Beyond Corn and Soybeans...Challenges to Integrated Pest Management in Specialty Crops.” Annual Meeting of the Entomological Society of America, Minneapolis, MN. November 15-18, 2015. (abstract)

Alyokhin, A. 2015. Con- and heterospecific influences on potato colonization by three species of aphids. Annual Meeting of the Entomological Society of America, Minneapolis, MN. November 15-18, 2015. (abstract)

Alyokhin, A. and A. Buzza. 2016. Epidemiology of Potato Virus Y in Northern Maine. Northeastern Plant, Pest, and Soils Conference, Philadelphia, PA. January 3-7, 2016. (abstract)

Bag, S., S.I. Rondon, K. Frost, D. Walenta, and B. Charlton. 2016. Monitoring aphids in seed and commercial potato fields in Oregon. In 75^th annual Pacific Northwest Insect Management Conference. Jan 11-12. Portland, OR. Section V. Pp 59-62. (abstract)

Bag, S., Frost, K., Rondon, S.I., Charlton, B.A., and D. Walenta. 2016. Variation in aphid abundance and Potato virus Y incidence in Oregon potato. APS Annual Meeting. July 30- Aug 3, Tampa, FL. Phytopathology 106 (Suppl. 4) S4.44 (abstract)

Bag, S., Rondon, S., Frost, K., Walenta, D. and B. Charlton. 2016. Monitoring aphids and potato virus Y in seed and commercial fields in Oregon. XXV International Congress of Entomology, September 25-30, Orlando, FL, USA. (abstract)

Beissinger, A. 2016. Proactive approaches for managing Potato virus Y in western Washington. M.S. Thesis, WSU Plant Pathology Department, Pullman, WA (136 pages).

Beissinger, A., Benedict, C.A., Goldberger, J., and Inglis, D.A. 2016. A sociological assessment of Potato virus Y in western Washington: Barriers and bridges to adopting new management practices. Ann. Mtg. Amer. Phytopath. Soc., S106:S4.119. July 30- Aug 3, Tampa, FL (abstract and poster presentation).

Beissinger, A., Goldberger, J.R., Benedict, C.A., and Inglis, D.A. 2017. Seed potatoes, virus management, and the non-   adoption of an agricultural innovation. Rural Sociology: doi:10.1111/ruso.12181.

Beissinger, A. and Inglis, D. March 2018. Greenhouse comparison of two detection methods for Potato virus Y^N-Wi at four potato growth stages. Plant Health Progress (19):71-75.

Beissinger, A., Benedict, C., and Inglis, D. 2018. Alternative sources of Potato virus Y in western Washington. WSU Extension Technical Bulletin: 49E. x p. (in press). 

Benedict, C., McMoran, D., Inglis, D., and Karasev, A.V. 2015. Tuber symptoms associated with recombinant strains of Potato virus Y in specialty potatoes under northwestern Washington growing conditions. Amer. J. of Potato Res. 92: 593-602.

Carroll, J.E., Smith, D.M., and Gray, S. M. 2016. Preferential acquisition and inoculation of PVY^NTN over PVY^O in potato by the green peach aphid Myzus persicae (Sulzer). J. Gen. Virol. 97: 797–802.

Cating, R. A., C.N. Funke, N. Kaur, P.B. Hamm, and K.E. Frost, 2015. A multiplex reverse transcription (RT) high-fidelity PCR protocol for the simultaneous detection of six viruses that cause potato tuber necrosis. American Journal of Potato Research 92:536-540.

Charkowski, A. O. 2017. The socioeconomic impact of emerging and re-emerging disease epidemics. Phytopathology 107 (12):161

Chikh-Ali, M., Rowley, J.S., Kuhl, J.C., Gray, S.M., and Karasev, A.V. 2014. Evidence of a monogenic nature of the Nz gene conferring resistance against Potato virus Y strain Z (PVY^Z) in potato. American Journal of Potato Research 91: 649-654.

Chikh-Ali, M., Alruwaili, H., Vander Pol, D., and Karasev, A.V. 2015. Molecular characterization of recombinant strains of Potato virus Y from Saudi Arabia. Plant Disease 100: 292-297.

Chikh-Ali, M., Bosque-Perez, N., Vander Pol, D., Sembel, D., and Karasev, A.V. 2015. Occurrence and molecular characterization of recombinant Potato virus Y^NTN (PVY^NTN) isolates from Sulawesi, Indonesia. Plant Disease 100: 269-275.

Chikh-Ali, M., Naidu, R., and Karasev, A.V. 2015. First report of Potato virus Y (PVY) strain PVY^C associated with a tomato disease in Kenya. Plant Disease 100:864.

Chikh-Ali, M., Vander Pol, D., Nikolaeva, O.V., Melzer, M.J., and Karasev, A.V. 2016. Biological and molecular characterization of a tomato isolate of Potato virus Y (PVY) of the PVYC lineage. Archives of Virology 161: 3561–3566.

Couture, J. J. 2015. Mapping variation in vegetation functioning using imaging spectroscopy (Invited), American Geophysical Union (AGU) Fall Meeting. Dec. 18, 2015. (abstract)

Couture J. J., Singh A., Charkowski A. O., Groves, R. L., Gray, S. M., Bethke, P. C., Townsend, P. A. 201x. Integrating spectroscopy with potato disease management. Plant Disease. Accepted with revisions. 

Domfeh, O., Bittara, F., and Gudmestad, N.C. 2015. Sensitivity of potato cultivars to Potato Mop Top virus-induced tuber necrosis. Plant Dis. 99:788-796.

Domfeh, O., Thompson, A.L. and Gudmestad, N.C. 2015. Sensitivity to tuber necrosis caused by Potato Mop Top virus in advanced potato (Solanum tuberosum L.) breeding selections. Amer. J. Potato Res. 92:636-647.

Domfeh, O. and Gudmestad, N.C. 2016. Effect of soil moisture on the development of Potato Mop Top virus-induced tuber necrosis. Plant Dis. 100:418-423.

Dwyer, J. D. 2015. Aphid Populations in 2014. Spudlines, Volume 50 Number 3.

Dwyer, J. D. 2015. When is the Best Time to Initiate PVY/Aphid Management Strategies.  Spudlines, Volume 50 Number 3.   

Dwyer, James, D., Dwyer, Marc. J. 2018. What We Have Learned About Aphids in the Last Five Years. Maine Potato Conference January 17 and 18, 2018. University of Maine at Presque Isle (abstract)

Dwyer, J., Dwyer, M., Alyokhin, A., Dill, J., Buzza, A. 2018. Aphid Tower Trapping Results in Maine. 9^th International IPM Symposium. Baltimore, Maryland (abstract)

Elwan, E.A., Abdel Aleem, E.E., Fattouh, F.A., Green, K.J., Tran, L.T., and Karasev, A.V. 2017. Occurrence of diverse recombinant strains of Potato virus Y circulating in potato fields in Egypt. Plant Disease, published on-line April 17, 2017

Frost, K.E., Gevens, A.J. and Groves, R.L.  2015.  Web-based pest and disease forecasting tool for enhanced processing vegetable crop management. In Proceedings of the 2015 Wisconsin Crop Management Conference Abstracts, January, 13-15, Alliant Energy Center, Madison, WI. (abstract)

Fulladolsa Palma, Ana Cristina. 2015. Management of Potato virus Y in potato. PhD diss., University of Wisconsin-Madison.

Fulladolsa, A. C., F. M. Navarro, R. Kota, K. Severson, J. P. Palta, and A. O. Charkowski. 2015. Application of marker assisted selection for Potato virus Y resistance in the University of Wisconsin Potato Breeding Program. American Journal of Potato Research 92 (3): 444-450.

Fulladolsa, A. Jansky, S., Halterman, D., Charkowski, A. 2016. Development of molecular markers tightly linked to Potato virus Y resistance gene Rychc in a diploid potato population. Phytopathology 106:14 (abstract)

Fulladolsa, A. C., Jansky, S. H., Smith, D. R., Abramczak, C. M., Charkowski, A. O. 2017. Development and evaluation of four molecular markers tightly linked to the Potato virus Y resistance gene Ry(chc) in diploid potato populations. Phytopathology 107 (12): 69 (abstract)

Fulladolsa, A.C., La Plant, K.E., Groves, R.L., Charkowski, A. 2018. Potato plants grown from minitubers are delayed in maturity, but are not more susceptible to Potato virus Y than plants grown from conventional seed. American Journal of Potato Research 95 (1): 45-53.

Funke, C., Frost, K., Olsen, N., and A.V. Karasev. 2016. Strain specific resistance to Potato virus Y (PVY) in potato efficiently reduces the prevalence of the PVYO strain under semi-field conditions. Phytoplathology 106 (Suppl. 4) S4.199.

Funke, C.N., Nikolaeva, O.V., Green, K.J., Tran, L.T., Chikh-Ali, M., Quintero-Ferrer, A., Cating, R., Frost, K.E., Hamm, P.B., Olsen, N., Pavek, M.J., GFray, S.M., Crosslin, J.M., and Karasev, A.V. 2017. Strain-specific resistance to Potato virus Y (PVY) in potato and its effect on the relative abundance of PVY strains in commercial potato fields. Plant Disease 101: 20-28 

Green, K.J., Brown, C.J., Gray, S.M., and Karasev, A.V. 2017. Phylogenetic study of recombinant strains of Potato virus Y. Virology 507: 40-52. 

Groves, R.L., Frost. K.E. and Huseth, A.S.  2014.  Integrating grower-driven and publically held data for improved plant protection.  In Proceedings of the 2014 Joint Meeting of the American Phytopathological Society & The Mycological Society of America (APS-CPS 2014), Annual Meeting Abstracts, Phytopathology 104:S3. pp.159. (abstract)

Groves, R.L. Charkowski, A.O. and Bethke, P.  2015.  Influence of viral stresses on potato storage quality.  In Proceedings of the 2015 University of Wisconsin - Wisconsin Potato and Vegetable Growers, Grower Education Conference , UW- Madison College of Agriculture and Life Sciences, Research Division and UWEX, Feb. 3-5, Steven’s Point, WI, 22:1pp. (abstract)

Groves, R.L., Frost, K.E. and Huseth, A.S.  2015.  Modeling Potato virus Y incidence in seed potato production using grower-driven data and landscape analyses. In Proceedings of the 2015 AFRI NIFA Sponsored Workshop: Enhancing Risk Index-Driven Decision Tools for Managing Insect Transmitted Plant Pathogens, Conference Abstracts, May 14-16, Asilomar Conference Grounds, Pacific Grove, CA. (http://ucanr.edu/sites/tospo/). (abstract)

Groves, R.L., Frost, K.E., Charkowski, A.O., Duerr, E., Huseth, A.S. and Crockford, A.B. 2015. Data Driven IPM: Accurate Predictions of Risk for Plant Protection. P-IE Section Symposium, Insecticide Resistance Management (IRM) vs. Integrated Pest Management (IPM): Overlap and Conflicts, IRAC US Symposium Series No. 11. Entomological Society of America Annual Meeting, Minneapolis, MN, November 15-18, 2015. (abstract)

Groves, R.L., Frost, K.E., and A. Charkowski. 2016. Grower-driven data reveals first principles in the management of Potato virus Y incidence in seed potato production. XXV International Congress of Entomology, Orlando, FL, September 25-30. DOI: 10.1603/ICE.2016.93731 (conference paper)

Huang, D. and Yan, G. P. 2016. Real-time and conventional PCR assays for identifying the stubby root nematode Paratrichodorus allius. American Phytopathological Society Annual Meeting, Tampa, FL, July 30-August 3, 2016. (abstract)

Huang, D., Yan, G. P., and Skantar, A. M. 2017. Quantification of Paratrichodorus allius in DNA extracted from soil using TaqMan Probe and SYBR Green real-time PCR assays. Nematology 19: 987-1001.

Huang, D., Yan, G. P., and Skantar, A. M. 2017. Development of real-time and conventional PCR assays for identifying stubby root nematode Paratrichodorus allius. Plant Disease 101:964-972.

Huang, D., Yan, G. P., Plaisance, A., Gudmestad, N. C., Whitworth, J., Frost, K., Brown, C. R., Hafez, S. L., Handoo, Z. A., and Skantar, A. M. 2017. Molecular detection, identification and quantification of Paratrichodorus allius from nematode individuals, communities and soil DNA. Abstracts of 56^th Annual Meeting of the Society of Nematologists, Williamsburg, Virginia, August 13-16. (abstract)

Huang, D., Yan, G. P., Gudmestad, N., Whitworth, J., Frost, K., Brown, C., Weimin, Y., Agudelo, P., and Crow, W. 2018. Molecular characterization and identification of stubby root nematode species from multiple states in the United States. Plant Disease 101 (6): 964-972.

Inglis, D.A. and Gundersen, B. 2015. Impact of Potato virus Y on the quality of specialty potato tubers. Pg. 7-14 in Proceedings of the Washington-Oregon Potato Conference. January 27-29, Kennewick, WA. (abstract)

Inglis, D.A. 2016. ‘Cracked’ potato tubers and Potato virus Y. Invited PAA Forum article, Spudman magazine, June 2016.

Inglis, D.A., Gundersen, B., and Beissinger, A. 2016. Evidence that tuber cracking in potato can be caused by Potato virus Y. Ann. Mtg. Pacific Div. Amer. Phytopathol. Soc. 106:S4.199, La Conner, WA (abstract and poster presentation).

Inglis, D.A., Gundersen, B., Beissinger, A., and Karasev, A.V. 2017. Foliar and tuber reactions of five fresh market potato cultivars with three Potato virus Y strains. Ann. Mtg. Amer. Phytopath. Soc., S10x:xxx, San Antonio, TX (abstract for poster presentation).

Inglis, D., Benedict, C., Gundersen, B., Beissinger, A., and McMoran, D. 201x. Proactive approaches for controlling recombinant strains of Potato virus Y in western Washington. WSU Extension Technical Bulletin: (submitted Feb 2018).

Karasev, A.V. 2015. A novel strain of Potato virus Y from tomato. 107th Annual Meeting of the American Phytopathological Society, August 3, 2015, Pasadena, CA (abstract)

Karasev, A. 2016. Characterization of recombinant Potato virus Y^NTN (PVY^NTN) isolates from Sulawesi, Indonesia. 108^th Annual Meeting of the American Phytopathological Society, July 30 - August 3, 2016, Tampa, FL (abstract and poster presentation).

Kaur, N., Cating, R.A., Dung, J.K.S., Frost, K.E., Robinson, B.A., and P.B. Hamm. 2016. First report of Potato mop-top virus infecting potato in Oregon. Plant Disease 100:2337.

Klein, M.L. and S.I. Rondon. 2016. Spatial and temporal analysis of aphids in eastern Oregon. In 75^th annual Pacific Northwest Insect Management Conference. 11-12 Jan. Portland, OR. Section V. Pp 62-64. (abstract)

Kuhl, J.C., R.G. Novy, J.L. Whitworth, M.S. Dibble, B. Schneider, and D. Hall. 2016. Development of Molecular Markers Closely Linked to the Potato Leafroll Virus Resistance Gene, Rlr etb, for use in Marker-Assisted Selection. American Journal of Potato Research 93:203-212.

McMoran, D.W., Benedict, C.A., and Inglis, D.A. 201x. Potato virus Y and organic potatoes in western Washington. WSU Extension Fact Sheet: (submitted Feb 2018).

Mallik, I. and Gudmestad, N.C. 2015. First report of Potato Mop Top virus causing potato tuber necrosis in Colorado and New Mexico. Plant Dis. 99:164.

Mondal, S., E.J. Wenninger, P.J.S. Hutchinson, J.L. Whitworth, D. Shrestha, S.D. Eigenbrode, and N.A. Bosque-Perez. 2016. Comparison of transmission efficiency of various isolates of Potato virus Y among three aphid vectors. Entomologia Experimentalis et Applicata 158:258-268.

Mondal, S. and Gray, S.M. 2017. Sequential acquisition of Potato virus Y strains by Myzus persicae favors the transmission of the emerging recombinant strains. Virus Research 241:116-124.

Mondal, S., Lin, Y.H., Carroll, J.E., Wenninger, E.J., Bosque-Perez, N.A., Whitworth, J.L., Hutchinson, P., Eigenbrode, S., Gray, S.M. 2017. Potato virus Y transmission efficiency from potato infected with single or multiple virus strains. Phytopathology 107:491-498.

Mondal, S., E.J. Wenninger, P.J.S. Hutchinson, J.L. Whitworth, D. Shrestha, S.D. Eigenbrode, N.A. Bosque-Pérez, and W.E. Snyder. 2017. Responses of Aphid Vectors of Potato leaf roll virus to Potato Varieties. Plant Disease 101:1812-1818.

Novy, R., J. Whitworth, J. Stark. 2016. Breeding for resistance to Potato virus Y and protocols to mitigate PVY in breeder seed.  American Journal of Potato Research 94:237

Novy, RG, Whitworth, JL, Stark, JC, Schneider, BL, Knowles, NR, Pavek, MJ, Knowles, LO, Charlton, BA, Sathuvalli, V, Yilma, S, Brown, CR, Thornton, M, Brandt, TL, Olsen, N.  2017.  Payette Russet: a Dual-Purpose Potato Cultivar with Cold-Sweetening Resistance, Low Acrylamide Formation, and Resistance to Late Blight and Potato Virus Y.  Am. J. Potato Research.  94:38-53.

Olsen, N. and A. Karasev. 2015. Going viral: discerning among common virus-induced diseases. Potato Grower Magazine 44(9):32. September 2015. http://www.potatogrower.com/2015/09/going-viral

Plaisance, A. and Yan, G. P. 2015. Comparison of two nematode extraction techniques. 2015. 54^th Annual Meeting of the Society of Nematologists, East Lansing, MI, July 19-24, 2015. (abstract)

Raikhy, G., N. Gudmestad, S.M. Gray, and H.R. Pappu. 2016. Genetic diversity of Tobacco rattle virus isolates in the US.  Paper presented at the 16th triennial meeting of the Virology Section of the European Association of Potato Research. May 31st to June 3rd 2016. (abstract)

Ramesh, S.V., G. Raikhy, C.R. Brown, J.L. Whitworth, and H.R. Pappu. 2014. Complete genomic characterization of a potato mop-top virus isolate from the United States. Archives of virology 159:3427-3433. DOI 10.1007/s00705-014-2214-0

Robinson, A., Domfeh, O., and Gudmestad, N. C. 2015. Potato Tuber Viruses: Mop-Top Management.  ND Extension Circular A1777. 2pp. https://www.ag.ndsu.edu/publications/crops/potato-tuber-viruses-mop-top-management/a1777.pdf

Rondon. S.I., Bag, S., Vinchesi, A., Goyer, A. and K. Frost. 2016. PVY vectors, vector-plant interactions and novel control methods in the western United States. 16^th triennial meeting of the virology section of the European Association of Potato Research, May 31 – June 3, Ljubljana, Slovenia. (abstract)

Rowley, J.S., Gray, S.M., and Karasev, A.V. 2015. Screening potato cultivars for new sources of resistance to Potato virus Y. American Journal of Potato Research 92: 38-48.

Shrestha, D., E.J. Wenninger, P.J.S. Hutchinson, J.L. Whitworth, S. Mondal, S.D. Eigenbrode, and N.A. Bosque-Perez. 2014. Interactions among potato genotypes, growth stages, virus strains, and inoculation methods in the potato virus y and green peach aphid pathosystem. Environmental Entomology 43:662-671.

Thomas-Sharma, S., Abdurahman, A., Ali, S., Andrade-Piedra, J. L., Bao, S., Charkowski, A. O., Crook, D., Kadian, M., Kromann, P., Struik, P. C., Torrance, L., Garrett, K.A., Forbes, G.A. 2016. Seed degeneration in potato: the need for an integrated seed health strategy to mitigate the problem in developing countries. Plant Pathology 65 (1):3-16.

Weber, B. N., R. A. Witherell, and A. O. Charkowski. 2015. Low-cost potato tissue culture with microwave and bleach media preparation and sterilization. American Journal of Potato Research 92:128-137.

Whitworth, Jonathan. 2016.  Potato virus Y is an industry-wide problem; challenges in removing PVY from seed.  American Journal of Potato Research 94:248

Yan, G. P. and Gudmestad, N.C. 2015. Stubby root nematode as the virus vector of corky ringspot disease of potato. 54^th Annual Meeting of the Society of Nematologists, East Lansing, MI, July 19-24, 2015. (abstract)

Yan, G. P., Plaisance, A., Huang, D., and Handoo, Z. A. 2016. First detection of the stubby root nematode Paratrichodorus allius on potato in North Dakota and on sugarbeet in Minnesota. American Phytopathological Society Annual Meeting, Tampa, FL, July 30-August 3, 2016. (abstract)

Yan, G. P., Plaisance, A., Huang, D., Upadhaya, A., Gudmestad, N. C., and Handoo, Z. A. 2016. First report of the stubby root nematode Paratrichodorus allius on potato in North Dakota. Plant Disease 100: 1247. http://dx.doi.org/10.1094/PDIS-11-15-1350-PDN.

Yan, G. P., Huang, D., Plaisance, A., Gudmestad, N. C., Whitworth, J., Frost, K., Brown, C. R., Ye, W., Crow, B., and Hafez, S. L. 2017. Species and population densities of stubby root nematodes from multiple states in the United States. Phytopathology 107:S5.96 (abstract).

Yellareddygari, S.K.R., Domfeh, O. Bittara, F.G., and Gudmestad, N.C. 2017. Analysis of Potato Mop-Top Virus survival probability in post-harvest storage. Amer. J. Potato Res. 94:632-637.

Yellareddygari, S.K.R, Brown, C.R., Whitworth, J.L., Quick, R.A., Hamlin, L.L., and Gudmestad, N.C. 2018. Assessing potato cultivar sensitivity to tuber necrosis caused by Tobacco rattle virus. Plant Dis. 102: (in press).

Yellareddygari, S.K.R, Whitworth, J.L., and Gudmestad, N.C. 2018. Assessing potato cultivar sensitivity to tuber necrosis caused by Potato mop-top virus. Plant Dis. 102: (in press).

Zeng, Y., Fulladosa, A. C., Houser, A., Charkowski, A. O. 2018. Colorado seed potato certification data analysis shows mosaic and blackleg are major diseases of seed potato and identifies tolerant potato varieties. Plant Disease. (near submission)

Zidack, N., Gray, S. Ugly Fight: Battling Tuber Necrotic Viruses. Potato Grower, May 2017.