PhD. (2011) – Biological Sciences: Plant Sciences; Oenology and Viticulture, Brock University

Certificate Grape & Wine Tech. (2004) – Brock University

BSc. (2001) – Biology, St. Mary’s University, Halifax, NS. Canada

OEVI 2P45 – Grapevine Cultural Practices

OEVI 2P99 – Grapevine Biology

Grapevine cold hardiness physiology; Freeze injury mitigation; scion x rootstock evaluations and interactions; plant growth regulators; Soil-water-plant interactions; Impact of viticultural practices on fruit quality and wine quality.

VineAlert: Grapevine Management and Monitoring System for Cold Hardiness and injury 

Learn more: http://www.ccovi.ca/vine-alert/

Recognized by the Council of Ontario University’s Research Matters campaign for its success in partnering with industry and had identified the program as one of 50 ‘game-changing’ research partnerships across the province. 

Grape Preharvest Monitoring Program

Learn more: http://www.ccovi.ca/preharvest

Best practices guides

Use of Geotextiles to mitigate freeze injury in Ontario Vineyards

Learn more: http://www.grapegrowersofontario.com/sites/default/files/Report%20geotextile%20willwerth%20Feb%202013.pdf

Best Practices to reduce freeze injury

Learn more: https://brocku.ca/ccovi/wp-content/uploads/sites/125/Research-Best-Practices-Manual-Winter-Injury.pdf

Attracting American Kestrels through the use of Nest boxes

Learn more: http://www.fitzgerald-and-co.com/kestrel-project.html

Pickering, G.P., Willwerth, J., Botezatu, A. and Thibodeau, M. (2021). Prevalence and management of alkyl-methoxypyrazines in a changing climate: viticultural and oenological considerations. Biomolecules. 11: 1521 https://doi.org/10.3390/biom11101521

Hébert-Haché A., Inglis. D., Kemp, B. and Willwerth, J. (2021). Clone and rootstock interactions influence the cold hardiness of Vitis vinifera cvs. Riesling and Sauvignon blanc. Am. J. Enol. Vitic. 72: 126-136 https://doi.org/10.5344/ajev.2020.20025

Jasinski, M., Hughes, M., Fraser, H., Fitzgerald, S. and Willwerth, J.J. (2021). Kestrel nest box occupancy and fledging rates and the effect of kestrel presence and absence on bird abundance and activity in fruiting crops in the Niagara Region and Norfolk County. Crop Protection. 139. (in press). https://doi.org/10.1016/j.cropro.2020.105377

Reynolds, A.G. and Willwerth, J.J.   (2020). Spatial variability in Ontario Riesling vineyards. I. Soil, vine water status and vine performance.  OENO One. 54(2):311-333.DOI: https://doi.org/10.20870/oeno-one.2020.54.2.2401

Willwerth, J.J. and Reynolds, A.G. (2020). Spatial variability in Ontario Riesling vineyards. II. Berry Composition. Can. J. Plant Sci. ( in press). DOI: https://doi.org/10.1139/cjps-2019-0291

Kemp, B., Trussler, S., Willwerth, J.J. and Inglis, D. (2019) Applying Temporal Check-All-That-Apply (TCATA) to mouthfeel and texture properties of red wines. Journal of Sensory Studies.  DOI: https://doi.org/10.1111/joss.12503

Kemp, B., Pickering, G., Willwerth, J.J. and Inglis, D.  (2018).   Investigating the use of partial napping with ultra-flash profiling to identify flavour differences in replicated, experimental wines. Journal of Wine Research. 29(4):302-309. DOI: https://doi.org/10.1080/09571264.2018.1532879

Willwerth, J.J., Reynolds, A.G. and Lesschaeve, I. (2018).   Sensory Analysis of Riesling Wines from Different Water Status Zones.  OENO One. 52(2):145-171. DOI:https://doi.org/10.20870/oeno-one.2018.52.2.1669

Bowen, P.A., Shellie, K.C., Mills, L., Willwerth, J., Bogdanoff, C., and Keller, M. (2016). Influence of Abscisic Acid Form, Concentration and Application Timing on Bud Cold Hardiness in Merlot Grapevines.  Can. J. Plant Sci. 96:347-359. DOI:https://doi.org/10.1139/cjps-2015-0257

Willwerth, J.J., Reynolds, A.G. and Lesschaeve, I. (2015).  Sensory Analysis of Riesling Wines from Different Sub-appellations Within the Niagara Peninsula. Am. J. Enol. Vitic. 66(3): 279-293.  DOI: https://doi.org/10.5344/ajev.2015.14081

Dami, I.E, Li., S., Bowen, P.A., Bogdanoff, C.P., Shellie, K.C., and Willwerth, J.J. (2015). Foliar Applied Abscisic Acid Increases Bud Freezing Tolerance of ‘Chardonnay’ Grapevines during Autumn Cold Acclimation. HortTechnology 25(3): 293-305. DOI: https://doi.org/10.21273/HORTTECH.25.3.293

Willwerth, J.J. (2011). Delineation of Within-site Terroir Effects using Soil and Vine Water Measurements in Riesling Vineyards within the Niagara Peninsula. PhD Thesis. Brock University, Canada. Read

Willwerth, J.J, Reynolds, A.G. and Lesschaeve, I. (2010). Terroir Factors: Their Impact in the Vineyard and on the Sensory Profiles of Riesling Wines. Les Facteurs du Terroir: Leur Impact dans le Vignoble et sur le Profil Sensoriel de vins de Riesling. Prog. Agric. Vitic. 8:159-168.

Reynolds, A.G., de Savigny, C. and Willwerth, J. (2010). Riesling Terroir in Ontario Vineyards. The Roles of Soil Texture, Vine Size and Vine Water Status. Prog. Agric. Vitic. 10:212-222.

Reynolds, A.G., Schlosser J., Power, R., Roberts, R., Willwerth, J. and de Savigny, C. (2007). Magnitude and Interaction of Viticultural and Enological Effects. I. Impact of Canopy Management and Yeast Strain on Sensory and Chemical Composition of Chardonnay Musque. Am. J. Enol. Vitic. 58:12-24.

Reynolds, A.G., Schlosser, J., Sorokowsky, D., Roberts, R., Willwerth, J. and de Savigny, C. (2007). Magnitude and Interaction of Viticultural and Enological Effects. II. Relative Impacts of Cluster Thinning and Yeast Strain on Composition and Sensory Attributes of Chardonnay Musque. Am. J. Enol. Vitic. 58:25-41.

Book Chapters

Kemp, B., Pedneault, K., Pickering, G., Usher, K., and Willwerth. J. (2019). Chapter 23: Red winemaking in Cool Climates.  In Red Wine Technology.  Antonio Morata (Ed.). Elsevier Science/Academic Press. pp. 341-356.

Conference Proceedings

Willwerth, J., Ker, K., Inglis, D., and Brewster, R. (2016). Grapevine cold hardiness and innovative strategies to mitigate freeze injury in Ontario, Canada.  9^th International Cool Climate Wine Symposium, Brighton, UK.   26-28 May, 2016.

Willwerth, J., Jasinski, M. and Dowling, L. (2014).  Impact of Cultural Practices on Cold Hardiness Dynamics of six V. vinifera cultivars.  American Society for Enology and Viticulture.  65^th ASEV National Conference and 39^th ASEV-ES Conference, Austin TX.  23-27 June, 2014.

http://www.asev.org/sites/main/files/file-attachments/2014technicalabstracts.pdf

Ker, K.W., Willwerth, J. and Brewster, R. (2013). Growing Season Weather Impact on Vine Hardiness.  38^th Annual Meeting American Society for Enology and Viticulture/Eastern Section, Winston-Salem, NC. 15-18 July, 2013, Am. J. Enol. Vitic. 64:416-424A.

Reynolds, A.G., Di Profio, F., Hakimi Rezaei, J., Jasinski, M. and J.J. Willwerth (2013). A hierarchal terroir model for Great Lakes viticulture. 18th International Symposium GiESCO 2013, Porto, Portugal, July 7-11, 2013, 976-986.

Willwerth, J. (2012).  Understanding Key Factors Affecting Cold Hardiness in Ontario: Optimization of Cold Tolerance and Reduction of Cold Injury in Grapevines.  39th Annual Conference of the Plant Growth Regulation Society of America.  Denver, CO. 22-26 July, 2012.

Willwerth, J., Reynolds, A.G. and Lesschaeve, I. (2009).  Terroir Factors:  Their Impact in the Vineyard and on the Sensory Profiles of Riesling Wines. Proc. 16^th International GIESCO 2009 Symposium, Davis, California USA, 12-15 July, 2009, pp. 13-18.

Technical and Editorial Publications

Hébert-Haché A., Willwerth, J.  (2017). Overview of freeze protection in vineyards. The Grape Press Vol. 167.  August 2017. Cowderoy, J. (Ed.).   United Kingdom Vineyards Association. United Kingdom.

Willwerth, J. (2016).  Bird deterrent strategies.  The Grape Press. Vol. 165.  August 2016. Cowderoy, J. (Ed.).  United Kingdom Vineyards Association. United Kingdom.

Kemp, B. and Willwerth, J. (2016).  Pinot noir research trials.  The Grape Press. Vol. 165.  August 2016. Cowderoy, J. (Ed.).  United Kingdom Vineyards Association. United Kingdom.

Selected Conference Proceedings, Posters, Abstracts, Presented Papers, etc. (2015-present)

Willwerth, J. (2020). Surviving the Polar Vortex:  Mitigating freeze injury in V. vinifera.  SW Hort Days meeting. Benton Harbor, MI. USA. 5-6 February, 2020.

Willwerth, J. (2019). Working together to improve the quality and sustainability of Ontario’s Vineyards through Research and Outreach.  Ontario Fruit and Vegetable Convention, Niagara Falls, ON. 20-21 February, 2019.

Hébert-Haché A., Willwerth, J., and Inglis. D. (2019). Clone and rootstock selection to reduce cold damage. Ontario Fruit and Vegetable Convention, Niagara Falls, ON. 20-21 February, 2019.

Kemp, B. and Willwerth, J. (2019). Soil type impacts on aromatics of sparkling wine. Ontario Fruit and Vegetable Convention, Niagara Falls, ON. 20-21 February, 2019.

Barker, A., Willwerth, J., Kemp, B. and Inglis, D. (2019). The effect of Riesling clone on vine performance, fruit composition and oenological potential. Ontario Fruit and Vegetable Convention, Niagara Falls, ON. 20-21 February, 2019. (poster)

Bodin, M., Kemp, B., Campbell, J., Willwerth, J., and Inglis, D. (2019). The effect on skin and seed tannin concentrations in sparkling wine and red grapes from the timing and severity of leaf removal. Ontario Fruit and Vegetable Convention, Niagara Falls, ON. 20-21 February, 2019. (poster)

Willwerth, J. (2019).  Cool season Canadian wines: Understanding the terroir effect within the Niagara Peninsula appellation.  Soils Across Latitudes.  Soil Science Society of America International Soils Meeting.  San Diego, CA. USA 6-9 January.

Barker, A., Willwerth, J., Kemp, B. and Inglis, D. (2018) The effect of grapevine clone on vine performance, fruit composition and oenological potential for core-Ontario varieties. 43^rd Annual Meeting American Society for Enology and Viticulture/Eastern Section, King of Prussia, PA 9-11 July, 2018.

Hébert-Haché A., Willwerth, J., Kemp, B. and Inglis. D. (2018). Isolation of dehydrin proteins in dormant buds of Vitis vinifera cv. Riesling and Sauvignon blanc.  43^rd Annual Meeting American Society for Enology and Viticulture/Eastern Section, King of Prussia, PA 9-11 July, 2018.

Willwerth, J. (2018). Production challenges and managing cold-hardy hybrid grape varieties. Cidres, Vins et alcools d’ici, Boucherville, QC. 27-28 March, 2018.

Willwerth, J. (2018). Improving hardiness and maintaining dormancy in grapevines using abscisic acid analogs. Ontario Fruit and Vegetable Convention, Niagara Falls, ON. 21-22 February, 2018.

Hébert-Haché A., Willwerth, J.., and Inglis. D. (2018). The impact of growing season on cold acclimation of Riesling and Sauvignon Blanc clones.  Ontario Fruit and Vegetable Convention, Niagara Falls, ON. 21-22 February, 2018. (poster)

Barker, A., Inglis. D, and Willwerth, J. (2018). Grapevine clone effects on fruit and wine quality.  Ontario Fruit and Vegetable Convention, Niagara Falls, ON. 21-22 February, 2018. (poster)

Hébert-Haché, A., Jasinski, M., Willwerth, J.J., and Inglis. D. (2017). Clone and Rootstock Interactions and their Influence on Cold Hardiness. 42^nd Annual Meeting American Society for Enology and Viticulture/Eastern Section, Charlottesville, VA. 10-12 July, 2017.

Willwerth, J. (2017).  Improving the Quality and Sustainability of Ontario’s Vineyards through Research and Outreach.  Atlantic Canada Wine Symposium, Halifax, NS. 11-13 June, 2017.

Willwerth, J., Ker, K. and Brewster, R. (2017). How Growing Seasons Can Impact Vine Hardiness. Did the Dry Season of 2016 Affect Cold Acclimation? Ontario Fruit and Vegetable Convention, Niagara Falls, ON. 22-23 February, 2017.

Willwerth, J., and Kemp, B. (2017). Effects of Leaf Removal on Sparkling and Still Wines for Pinot Noir.  Ontario Fruit and Vegetable Convention, Niagara Falls, ON. 22-23 February, 2017.

Jasinski, M., Willwerth, J., and Hughes, M. (2017). Field testing Kestrel nest boxes to prevent bird damage in horticulture crops. Ontario Fruit and Vegetable Convention, Niagara Falls, ON. 22-23 February, 2017. (poster)

Willwerth, J., and Jasinski. M. (2016).  The use of geotextiles to reduce freeze injury in grapevines.  41^st Annual Meeting American Society for Enology and Viticulture/Eastern Section, St. Louis. MO. 18-21 July, 2016.

Hébert-Haché A, Jasinski, M., Inglis, D., and Willwerth, J. (2016).  Impact of clone and rootstock selection on Riesling and Sauvignon blanc winter hardiness.  41^st Annual Meeting American Society for Enology and Viticulture/Eastern Section, St. Louis. MO. 18-21 July, 2016. (poster)

van der Merwe, P., Kemp, B., Willwerth, J., Jasinski., M., and Inglis. D. (2016). The impact of severity and timing of leaf removal on Pinot noir sparkling wine juice and base wines. 9^th International Cool Climate Symposium, Brighton, UK.   26-28 May, 2016. (poster)

Willwerth, J., and Jasinski., M. (2016).  New techniques for managing birds in Ontario.  Ontario Fruit and Vegetable Convention, Niagara Falls, ON. 17-18 February, 2016.

Onguta, E., Dowling, L., Kemp, B., Willwerth, J., van der Merwe, G. and Inglis, D. (2015).  The suitability of L. cv. Pinot noir Mariafeld for sparkling wine production in Niagara, Ontario. 40^th Annual Meeting American Society for Enology and Viticulture/Eastern Section, Dunkirk, NY. 23-25 July, 2015 (poster).

Onguta, E., Dowling, L., Kemp, B., Willwerth, J., van der Merwe, G. and Inglis, D. (2015). Increasing sparkling wine quality, productivity and winery revenue with press fractioning of L. cv. Pinot noir clone 115 in Ontario.  40^th Annual Meeting American Society for Enology and Viticulture/Eastern Section, Dunkirk, NY. 23-25 July, 2015.

Willwerth, J. (2015). Grapevine cold hardiness research and strategies to mitigate freeze injury in Ontario.  16th Annual British Columbia Wine Grape Council’s Enology & Viticulture Conference, Pentiction, BC. 20-21 July, 2015.