Overview

My research program focuses on the epidemiology and management of bacterial, fungal, and viral diseases of fresh market vegetable crops (esp. potatoes, cucurbits, and tomato) grown in upstate New York. I integrate my program by working cooperatively with scientists in other disciplines to evaluate chemical and biological agents, varietal resistance, and cultural disease management strategies for a number of vegetable crops. My work has relevancy for conventional and organic production of vegetable crops. For tomato we work cooperatively with a plant breeder to develop tomato varieties with multiple disease resistance by conventional breeding methods. For potatoes we study the use of sustainable and conventional products as seed piece, in-furrow or foliar application to minimize the lost of foliage and produce more blemish-free tubers. For cucurbits we evaluate products to minimize the effects of bacterial and fungal pathogens.

Research Focus

Following the characterization of the Alternaria species affecting potato (A. solani) and tomato (A. tomatophila) in terms of morphology and pathogenicity, and demonstrated that two species of Alternaria are responsible for early blight of tomato and potato, we applied this information in the pursuit of improving the selection of disease resistant tomato lines and hybrids. Genetic resistance to early blight and late blight has been fixed in tomato lines and these lines have been field tested to select for superior performance of earliness and yield potential in two locations in NY. Additionally we have initiated a screen program using some existing germplasm with notable traits to identify the highest level of resistance for Septoria leaf spot. Our goal is to develop tomato lines and hybrids with multiple disease resistance that would be adapted to NE growing conditions. Knowing that some fungicide use may still be required, we are working to pyramid genetic resistance with "lite " treatments which include biologicals or reduce risk materials. In potato we are working with a horticulturist to reduce the damaging effects of silver scurf, black scurf, black dot and most recently common scab by integrating seed and in-furrow treatments with foliar applications, and postharvest treatments such as with potassium sorbate salt. In addition to the use of salt solutions, we investigated the use of phosphoric acid solutions for oomycete control. We evaluate existing and new potato cultivars for their reaction to several diseases. For cucurbits we studied the epidemiology of bacterial leaf spot of cucurbits and verified methods to reduce the spread of bacteria via seed by evaluating several seed treatments. We continue to follow the control of powdery mildew in cucurbits in the face of continued loss of fungicides due to fungal resistance.

Outreach and Extension Focus

My extension program consists of developing and reporting disease management strategies that are both economically and environmentally sound for fresh market vegetable production. We hope that some of this testing will result in practices adaptable for organic production. I developed the Vegetable MD online Web Site to serve as a modern vehicle for delivering vegetable disease information in a highly appealing format for use by interested parties throughout the world. During 2007 the site received over 1.9 million hits. I have made available countless number of disease images for use in agent/grower education via the web. I am responsible for writing and coordinating vegetable disease sections in Pest Management Guidelines for Commercial Vegetable and Potato Production. I make frequent recommendations. I am a frequent speaker at vegetable conferences thorough the northeast US and beyond.

Instruction Focus

PlPath 650 - Diseases of Vegetable Crops PlPath 661 - Diagnostic Lab Experience

Additional Links

• Department of Plant Pathology and Plant-Microbe Biology Vegetable MD Online
• Link to Cornell University Outreach Po
• Vegetable MD Online
• Zitter lab and field program
• Zitter Lab Page
• Link to CALS Research portal
• Link to CALS Impact statements

Honors, Awards and Appointments

• 2008 APS Fellow Award, The American Phytopathological annual meeting - 2008
• 2005 CALS Research and Extension Award in Career Accomplishments - 2005
• 2002 APS Excellence in Extension, The American Phytopathological annual meeting - 2002
• 2001 Excellence in IPM, New York State IPM program - 2001

Professional Activities

• 2006 Cucurbitaceae. Asheville, NC. Bacterial spot (Xanthomonas campestris pv. cucurbitae) As a Factor in Cucurbit Production and evaluation of Seed Treatments for Control in Naturally-infected Seeds. (150 attendees) - Sept 17-21, 2006
• 2006 Cucurbitaceae 2006; Asheville, NC. Initiating Sudden Wilt Disorder in Muskmelon with low Light Stress. (150 attendees) - Sept 17-21, 2006
• 2007 22nd Tomato Disease Workshop, Williamsburg, VA. Evaluation of Lite Fungicides for Early Blight and Septoria Leaf Spot Control and Pyramiding Fungicides with Genetic Resistance. (100 attendees) - Oct 25, 2007
• 2006 21st Tomato Disease Workshop. Fletcher, NC. Efficacy of Fungicides for Early Blight and Late Blight Control. (75 attendees) - Nov 9-10, 2006
• 2006 21st Tomato Disease Workshop.Fletcher, NC. Effectiveness of Genetic Resistance and Lite Fungicides for Disease Control. (75 attendees) - Nov 9-10, 2006
• 2006 INIA, Las Brujas, Uruguay SA, Tomato and Cucurbit Disease Update. (25 attendees) - Mar 7-8, 2006
• 2006 Hudson Valley Vegetable Growers Meeting. Newburgh, NY. Cucurbit Disease Controls. (45 attendees) - Mar. 16, 2006
• 2006 APS Annual Meeting.Quebec City, Canada. (poster) The Efficacy of Environmentally Friendly Compounds in Controlling Silver Scurf in Naturally Infected Potatoes During Storage. (1600 attendees) - July 29-Aug 2, 2006
• 2007 APS Annual Meeting. San Diego, CA. (poster) Screening Potato Cultivars suitable for Production in Northeast America for Response to Colletotrichum coccodes and Phytophthora erythroseptica. (1600 attendees) - July 28-Aug 1, 2007
• 2006 1st International Congress of Tomato Production and Commercialization.Guadalajara, Mexico. Combining Early Blight and Late Blight Resistance. (550 attendees) - Jul 19-21, 2006
• 2006 1st International Congress of Tomato Production and Commercialization. Guadalajara, Mexico. Late Blight and Early Blight Infections of Tomato. (550 attendees) - Jul 19-21, 2006
• 2007 Finger Lakes Produce Auction Meeting, Penn Yan, NY. Management of Powdery and Downy Mildew in Pumpkins (100 attendees). - Jan 8, 2007
• 2006 Finger Lakes Produce Auction, Penn Yan, NY. Update on Vine Crop Disease Management. (125 attendees) - Jan 6, 2006
• 2006 Long Island Agricultural Forum. Riverhead, NY. Update on pre- and post harvest disease control. (85 attendees) - Jan 19, 2006
• 2006 UAP Potato Workshop.Atlantic City, NJ. Soil borne diseases of potato (125 attendees). - Feb 9-10, 2007
• 2006 Empire State Fruit and Vegetable Expo. Syracuse, NY, (3 talks with proceedings); Update on treatments used for seed piece and post harvest disease control (75 attendees); Learning to recognize and manage virus diseases of cucurbits (90 attendees); An overview of tomato, pepper and eggplant diseases (95 attendees) - Feb 14-16, 2006
• 2007 Empire State Fruit and Vegetable Expo.Syracuse, NY. (2 talks and proceedings) Potato Fungicide Treatments (20 attendees, snow storm); Effectiveness of Genetic Resistance and Lite Fungicides for Control of Early Blight and Late Blight in Tomato (50 attendees). - Feb 14, 2007
• 2007 Mid-Atlantic Fruit and Vegetable Convention.Hershey, PA. An Overview of Tomato Diseases (125 attendees). - Feb 1, 2007
• 2007 INIA, Las Brujas, Uruguay SA. Potato, Tomato and Cucurbit Disease Update. (25 attendees) - Feb. 27-28, 2007
• 2008 APS Centennial Meeting, Minneapolis, MN. (oral) Phytophthora erythroseptica, isolate sensitivity to metalaxyl and disease control in New York and Pennsylvania (1700 attendees) - July 26-30, 2008. - 2008
• 2008 Long Island Agricultural Forum. Riverhead, NY. (oral) Fungicide update and varietal susceptibility to disease. (85 attendees) - Jan 10, 2008. - 2008
• 2008 Mid-Atlantic Vegetable Conference. Hershey, PA. (oral talk and proceedings) Update on fungicides for seed piece, in-furrow and foliage for control of potato diseases. (75 attendees) - Jan 30, 2008. - 2008
• 2008 NYS Vegetable Expo. Syracuse, NY (oral talk and proceedings) Pink rot, problems, propests and Cornell. (50 attendees), Feb 13, 2008. - 2008
• 2008 Capital District Small Fruit and Vegetable Growers Winter Meeting. Albany, NY. (oral) Cucurbit virus update. (100 attendees) - March 13, 2008. - 2008

Selected Publications

• Jones, J. B., Jones, J. P., Zitter, T. A., Momol, T. M., and Polston, J. E. 2008. Compendium of Tomato Diseases. 2nd Edition. APS Press. St. Paul, MN (in review).
• Zitter, T. A., and Drennan, J. L. 2008. Using host resistance and lite fungicides to control early blight on tomato, 2006. Report 2:V060. DOI:10.1094/PDMR02. The American Phytopathological Society, St. Paul, MN.
• Zitter, T. A., and Drennan, J. L. 2008. Fungicides for controlling early and late blight in tomato, 2007. Report 2:V058. DOI:10.1094/PDMR02. The American Phytopathological Society, St. Paul, MN.
• Zitter, T. A., and Drennan, J. L. 2008. Comparing fungicides for powdery mildew control in butternut squash, 2007. Plant Disease Management Reports (online). Report 2:V062. DOI:10.1094/PDMR02. The American Phytopathological Society, St. Paul, MN.
• Zitter, T. A., and Drennan, J. L. 2008. Using host resistance and lite fungicides to control early blight and Septoria leaf spot on tomato, 2007. Report 2:V061. DOI:10.1094/PDMR02. The American Phytopathological Society, St. Paul, MN.
• Zitter, T. A., Drennan, J. L., Halseth, D. E., and Sandsted, E. R. 2008. Combination of seed piece and foliar fungicides to improve tuber appearance and early blight control in potato, 2007. Plant Disease Management Reports (online). Report 2:ST011. DOI:10.1094/PDMR02. The American Phytopathological Society, St. Paul, MN.
• Griffiths, H. M., Zitter, T. A., Deahl, K. L., and Halseth, D. E. 2008. Phytophthora erythroseptica, isolate sensitivity to metalaxyl and disease control in New York and Pennsylvania. Phytopathology 98:S62.
• Jones, J. B., Jones, J. P., Zitter, T. A., Momol, T. M., and Polston, J. E. 2008. Compendium of Tomato Diseases. 2nd Edition. APS Press. St. Paul, MN (in preparation).
• Griffiths, H. M., Zitter, T. A., and Halseth, D. E. 2007. Screening potato cultivars suitable for production in Northeast America for response to Colletotrichum coccodes and Phytophthora erythroseptica. Phytopathology 97:S43.
• Zitter, T. A., and Drennan, J. L. 2007. Fungicides for controlling early and late blight in tomato, 2006. Plant Disease Management Reports (online). Report 1:V001. DOI: 10.1094/PDMR01. The American Phytopathological Society, St. Paul, MN.
• Zitter, T. A., and Drennan, J. L. 2007. Comparing fungicides for powdery mildew control in butternut squash, 2006. Plant Disease Management Reports (online). Report 1:V002. DOI: 10.1094/PDMR01. The American Phytopathological Society, St. Paul, MN.
• Zitter, T. A., Drennan, J. L., Halseth, D. E., and Sandsted, E. R. 2007. Biofungicides and sustainable products compared with conventional fungicides for potato production, 2006. Plant Disease Management Reports (online). Report 1:V064. DOI: 10.1094/PDMR01. The American Phytopathological Society, St. Paul, MN.
• Griffiths, H. M., and Zitter, T. A. 2006. The efficacy of environmentally friendly compounds in controlling silver scurf in naturally infected potatoes during storage. Phytopathology 96:S43. (Abstract)
• Mutschler, M., Zitter, T. A., and Bornt, C. 2006. Effectiveness of genetic resistance and lite fungicides for disease control. Proceedings 21st Annual Tomato Disease Workshop, Asheville, NC. (online) http://cherokeereservation.ces.ncsu.edu/fletcher/programs/plantpath/2006-11-tomato-disease/TDW06proceedings.pdf
• Ozdemir, Z., and Zitter, T. A. 2006. Bacterial leaf spot (Xanthomonas campestris pv. cucurbitae as a factor in cucurbit production and evaluation of seed treatments for control in naturally infested seeds. Pages 498-506.Proceedings of Cucurbitaceae 2006. G. J. Holmes, ed. Universal Press, Raleigh, NC.
• Zitter, T A., and Drennan, J. L. 2006. Efficacy of fungicides for early blight and late blight control. Proceedings 21st Annual Tomato Disease Workshop, Asheville, NC (online) http://cherokeereservation.ces.ncsu.edu/fletcher/programs/plantpath/2006-11-tomato-disease/TDW06proceedings.pdf
• Zitter, T. A., Drennan, J. L., Mutschler, M. A., and Kim, M. -J. 2005. Control of early blight of tomato with genetic resistance and conventional and biological sprays. Acta Hort. 695: 181-190.
• Zitter, T. A., Hopkins, D. L., and Thomas, C. E., Eds. 1996. Compendium of Cucurbit Diseases. The American Phytopathological Society. APS Press. St. Paul, MN. 86 pp.
• Jones, J. B., Jones, J. P., Stall, R. E., and Zitter, T. A., Eds. 1991. Compendium of Tomato Diseases. The American Phytopathological Society. APS Press. St. Paul, MN. 73pp.

[top]