Source: CORNELL UNIVERSITY submitted to NRP
BIOLOGY AND MANAGEMENT OF FIELD CROP DISEASES IN NEW YORK
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0198481
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Oct 1, 2009
Project End Date
Sep 30, 2012
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
CORNELL UNIVERSITY
(N/A)
ITHACA,NY 14853
Performing Department
Plant Pathology
Non Technical Summary
Field crops (including corn, soybean, wheat, alfalfa and other hay crops, perennial grasses) play an integral role in the New York economy by providing feed for animal industries, principal ingredients for food products produced in the state, and feedstocks for biofuels. Both chronic and currently undermanaged, and emerging plant diseases are a continual threat to New York field crops and can reduce the already narrow profit margin for producers. This project addresses the most critical and timely crop disease management issues and directly supports several extension education initiatives. The project provides basal support for the plant pathology research component of an integrated field crops management program. It offers both fundamental contributions to disease epidemiology and management, and short-term research results on disease management tactics that can be recommended to extension educators, agribusiness, and growers. Methods employed include farm survey; experimental field plot assessment of cultivars, fungicides, biological control agents and cultural practices; controlled environment experiments; molecular genetic evaluation of pathogen populations; and aerobiology methods for studying fungal spore dispersal. Research efforts in the next 3 years will be focused on the biology and management of mycotoxin producing fungi in corn and wheat; viruses and foliar fungal diseases of wheat; brown root rot of forage legumes; disease management with resistant culitvars and clean seed programs in biofuel feedstock grasses; and optimized use of fungicides in the protection of corn, soybean and wheat. Intended outcomes include guidelines for disease management tactics that have been validated under New York conditions. Field crop producers will benefit financially from more efficient production of their crops (less disease-induced losses and savings from unnecessary application of control measures). Animal producers; feed, food, and biofuel processors; farm service providers; rural communities; and all consumers will benefit from the contributions of disease management to sustainable field crops production. Project directions are influenced through contact of the project leader with individual stakeholders as well as with the New York Corn Growers Association, New York State Agribusiness Association, New York Biomass Energy Alliance, New York Small Grain Seed Producers Committee, Northeast Certified Crop Advisors Program, New York Farm Viability Institute, and the Integrated Field Crop, Soil, and Pest Management Program Work Team (project leader is the co-chair). The project leader delivers extension education programs on field crop disease management that are based, in large part, on results from this research project.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2121510116010%
2121542116040%
2121629116030%
2121640116010%
2121820116010%
Knowledge Area
212 - Pathogens and Nematodes Affecting Plants;

Subject Of Investigation
1510 - Corn; 1542 - Soft red wheat; 1629 - Perennial grasses, other; 1640 - Alfalfa; 1820 - Soybean;

Field Of Science
1160 - Pathology;
Goals / Objectives
This project will assess potential disease threats before they become widespread economic problems in New York as well as reduce the impact of already occurring and undermanaged, chronic diseases. Research on disease cycles will allow identification of points of intervention that should lead to effective strategies for avoiding and managing diseases. Intended outcomes include recommendations for disease management tactics that are valid for New York conditions. In particular, we will discern the relative efficacy of resistant crop cultivars, chemical and biological seed treatments, crop sequences and other cultural practices on disease control and crop production efficiency. Specific research objectives are: 1. Study aspects of the biology and epidemiology of emerging field crop diseases that will contribute to an understanding of disease potential and methods of control; assess resistance of crop cultivars and efficacy of fungicides for disease management. 2. Assess the etiology and occurrence of diseases affecting switchgrass and other biofuel feedstock grasses, and begin to develop best management practices that will limit their impact. 3. Further characterize the epidemiology and integrated management of Gibberella zeae, incitant of wheat scab and Gibberella ear rot of corn. 4. Elucidate the biology, epidemiology, and integrated management of diseases in winter wheat, especially fungal leaf blotches and soilborne viruses. 5. Assess alfalfa genotypes for susceptibility to variants of the Phoma sclerotioides species complex recently found to occur widely in New York soils. 6. Develop best management practices for the appropriate use of fungicides in the production of corn and soybean. The impact of this research project and resulting educational programs will be a more profitable and sustainable field crops production sector in New York as well as more profitable animal, food processing, and biofuel production industries in the state. Targeted beneficiaries of this project are the cash grain and forage producers of New York who should benefit financially from more efficient production of their crops (less disease-induced losses). Animal producers, rural communities, farm service suppliers, and all consumers and citizens of the state should also receive benefits from better disease management in the form of higher quality commodities for animal feed and human food and the general economic benefits of a more competitive field crops sector in the state.
Project Methods
Methods employed include farm survey; laboratory diagnosis; experimental field plot assessment of cultivars, chemicals, biological control agents and cultural practices; controlled environment experiments; molecular genetic evaluation of pathogen populations; and aerobiology methods for studying fungal spore dispersal. Research efforts in the immediate future will be focused on the biology and management of mycotoxin-producing fungi in corn and wheat, brown root rot in forage legumes, Stagonospora nodorum blotch of wheat, and soilborne viruses of wheat, and fungal diseases of switchgrass and other biofuel feedstock grasses. Research is conducted in replicated and repeated experiments with appropriate design and the data are analyzed by statistical analyses that are well accepted by the plant pathology and crop science research communities. Outlets for the research findings include peer reviewed scientific journals as well as extension publications and internet listserves. The project leader (0.7 FTE Extension) delivers extension education programs on field crop disease management in New York that are based, in large part, on results from this research project. Interactions with Extension audiences also inform needs identification for the research effort. Extension clientele and extension educators are also direct cooperators in the applied research program and play a large role in project evaluation and redirection of efforts.

Progress 10/01/09 to 09/30/12

Outputs
OUTPUTS: The most significant outputs over the 3-year course of this project include disease surveys and assessments of disease management practices in corn, soybean, wheat, alfalfa, and perennial grasses. Management practices have included crop varieties varying in resistance, fungicide application, cultural practices including crop rotation sequence and tillage. We have also continued collection and characterization of field crop pathogens for genetic and pathogenic diversity. We have documented several new pathogen occurrences in New York. We have made major strides toward assessing the sensitivity of fungal pathogens to fungicides, especially of Fusarium graminearum isolates to triazole fungicides. Results have been shared on an annual basis with New York stakeholders and cooperators through field days, meetings, workshops, extension publications, listserves, and through the cornell field crops website, fieldcrops.org. Results have also been shared with regional and national stakeholders and peers through refereed and trade journals, and professional committees and conferences. PARTICIPANTS: Worked on project: Gary Bergstrom CU - Plant Pathology - project PI; Katrina Waxman and Jaime Cummings CU - Plant Pathology Research Support Specialists - contributed to all aspects of project; Stanley Kawamoto CU - Plant Pathology Research Support Specialist - biological control studies; Julia Crane CU - Plant Pathology Graduate Research Assistant - biological control of Fusarium; Christine Layton CU - Plant Pathology Graduate Research Assistant - switchgrass smut; Marshall Hayes CU - Plant Pathology Research Associate - molecular and population ecology studies; Hannah Baughmann CU - undergraduate student research assistant; Elizabeth Burrichter CU - undergraduate student research assistant; Cooperated on project: Field Crop Extension Educators Cornell Cooperative Extension collaborators in on-farm trials and disease surveys across New York; Don Viands CU - Plant Breeding forage breeding and variety evaluation; Donna Gibson USDA-ARS at CU natural product chemistry and biological control; Hilary Mayton CU - Plant Breeding coordinate grass biofuel field trials; Karyn Bischoff CU - Veterinary Medicine mycotoxin evaluation; Larry Walker CU - Biol. Environ. Engineering biofuel technology; Mark Sorrells CU - Plant Breeding wheat breeding and cultivar evaluation; Martin Van der Grinten USDA-NRCS-Plant Materials Center at Big Flats, NY field assessment of bioenergy crops; Paul Stachowski CUAES - Farm Operations coordinate field operations at Musgrave Farm; Russ Hahn CU - Crop and Soil Science pesticide applications at Musgrave Farm; William Cox CU - Crop and Soil Science management of corn, soybean, and wheat crops TARGET AUDIENCES: Targeted beneficiaries of this project are the cash grain, forage, and perennial grass producers of New York who benefit financially from more efficient production of their crops (less disease-induced losses and savings from unnecessary application of control measures). Animal producers; feed, food, and biofuel processors; rural communities; farm service suppliers; and all consumers and citizens of the state also receive benefits from better disease management in the form of higher quality commodities for animal feed and human food and the general economic benefits of a more competitive field crops sector in the state. Research results generated through this project are transmitted in a timely manner to crop advisers and cooperative extension educators who are in turn better able to advise their clients on disease management issues. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The most significant outcomes over the 3 year period of this project include the identification and dissemination of the best integrated methods, including resistant varieties and effective fungicides, for management of Fusarium head blight and foliar diseases of wheat. We identified three new switchgrass diseases, anthracnose, Bipolaris leaf spot and smut, that threaten the future productivity of this biomass/biofuel crop and we identified varieties of the crop that were more resistant than other varieties and therefore a starting point for crop genetic improvement. We began long-term work in cooperation with alfalfa breeders to identify alfalfa genotypes that will survive and yield best in the presence of the brown root rot fungus, Phoma sclerotioides. In concert with New York corn growers, consultants, and extension educators, we began collaborative efforts to assess the economic benefits of fungicide application to field corn under low and high disease pressure. We documented disease problems in New York's expanding acreage of soybean. The most recent outcome was the documentation of a new virus disease caused by Soybean vein necrosis-associated virus in 14 New York counties in 2012.

Publications

  • Willyerd, K. T., C. Li, L.V. Madden, C.A. Bradley, G.C. Bergstrom, L.E. Sweets, M. McMullen, J.K. Ransom, A. Grybauskas, L. Osborne, S.N. Wegulo, D.E. Hershman, K. Wise, W.W. Bockus, D. Groth, R. Dill-Macky, E. Milus, P.D. Esker, K.D. Waxman, E.A. Adee, S.E. Ebelhar, B.G. Young, and P.A. Paul, P. A. 2012. Efficacy and stability of integrating fungicide and cultivar resistance to manage Fusarium head blight and deoxynivalenol in wheat. Plant Disease 96:957-967.
  • Bergstrom, G.C. 2012. New insights on cereal debris management for the reduction of head blight and mycotoxins. Page 39 in Proceedings of the 7th International IPM Symposium, Memphis, TN [www.ipmcenters.com/ipmsymposium12]
  • Waxman, K.D., G.C. Bergstrom, R.J. Richtmyer III, and R.R. Hahn. 2012. Evaluation of foliar fungicides for control of Fusarium head blight of winter wheat in New York, 2011. Plant Disease Management Reports 6: CF009.
  • Waxman, K.D., G.C. Bergstrom, R.J. Richtmyer III, and R.R. Hahn. 2012. Evaluation of foliar fungicides for control of foliar diseases and Fusarium head blight of winter wheat in New York, 2011. Plant Disease Management Reports 6: CF007.
  • Waxman, K.D., G.C. Bergstrom, R.J. Richtmyer III, and R.R. Hahn. 2012. Evaluation of integrated methods for management of Fusarium head blight and foliar diseases of winter wheat in New York, 2011. Plant Disease Management Reports 6: CF010.
  • Waxman, K.D., G.C. Bergstrom, R.J. Richtmyer III, and R.R. Hahn. 2012. Evaluation of a biological control agent and an isoparaffin oil for management of Fusarium head blight of winter wheat in New York, 2011. Plant Disease Management Reports 6: CF008.


Progress 10/01/10 to 09/30/11

Outputs
OUTPUTS: A new virus disease, incited by soybean vein necrosis virus, was identified in soybean production fields in Herkimer and Ontario Counties of New York late in the growing season. It is hypothesized that this virus is transmitted by thrips. Considerable research is needed to categorize the threat and to identify appropriate control strategies. We initiated an agricultural-scale, multi-year study of the local effect of corn debris on the development of Fusarium head blight and mycotoxin in wheat (plowed vs. no-till following corn harvest). Foliar fungicides and wheat varieties partially resistant (to Fusarium head blight, FHB) were evaluated in 2011 with and without inoculation with Fusarium graminearum, and planted into corn stubble or soybean stubble; only moderate severities were observed. The greatest reductions in FHB and DON were observed in partially resistant varieties sprayed at flowering with the triazole fungicide Prosaro. Geographically diverse collections of wheat heads and corn ears were made in 2011 for isolation of Fusarium graminearum and characterization of trichothecene genotypes occurring in New York State. Pre-commercial corn hybrids were evaluated for resistance to Gibberella ear rot; moderately resistant phenotypes (i.e., reduced colonization of the ear) were observed over a broad range of maturity groups. Foliar fungicide (Headline) applied in treated strips in a commercial field of grain corn in Cayuga Co. exhibited no significant effect on yield in the absence of significant foliar disease in August. First confirmations (with proof of pathogenicity) in New York were reported for three new diseases of switchgrass: anthracnose (Colletotrichum navitas), Bipolaris leaf spot (Bipolaris oryzae), and smut (Tilletia maclaganii). PARTICIPANTS: Worked on project: Gary Bergstrom CU - Plant Pathology - project PI; Katrina Waxman CU - Plant Pathology Research Support Specialist - contributed to all aspects of project; Stanley Kawamoto CU - Plant Pathology Research Support Specialist - biological control studies; Julia Crane CU - Plant Pathology Graduate Research Assistant - biological control of Fusarium; Christine Layton CU - Plant Pathology Graduate Research Assistant - switchgrass smut; Marshall Hayes CU - Plant Pathology Research Associate - molecular and population ecology studies; Hannah Baughmann CU - undergraduate student research assistant; Elizabeth Burrichter CU - undergraduate student research assistant; Cooperated on project: Field Crop Extension Educators Cornell Cooperative Extension collaborators in on-farm trials and disease surveys across New York; Don Viands CU - Plant Breeding forage breeding and variety evaluation; Donna Gibson USDA-ARS at CU natural product chemistry and biological control; Hilary Mayton CU - Plant Breeding coordinate grass biofuel field trials; Karyn Bischoff CU - Veterinary Medicine mycotoxin evaluation; Larry Walker CU - Biol. Environ. Engineering biofuel technology; Mark Sorrells CU - Plant Breeding wheat breeding and cultivar evaluation; Martin Van der Grinten USDA-NRCS-Plant Materials Center at Big Flats, NY field assessment of bioenergy crops; Paul Stachowski CUAES - Farm Operations coordinate field operations at Musgrave Farm; Russ Hahn CU - Crop and Soil Science pesticide applications at Musgrave Farm; William Cox CU - Crop and Soil Science management of corn, soybean, and wheat crops TARGET AUDIENCES: Targeted beneficiaries of this project are the cash grain, forage, and perennial grass producers of New York who benefit financially from more efficient production of their crops (less disease-induced losses and savings from unnecessary application of control measures). Animal producers; feed, food, and biofuel processors; rural communities; farm service suppliers; and all consumers and citizens of the state also receive benefits from better disease management in the form of higher quality commodities for animal feed and human food and the general economic benefits of a more competitive field crops sector in the state. Research results generated through this project are transmitted in a timely manner to crop advisers and cooperative extension educators who are in turn better able to advise their clients on disease management issues. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The finding of soybean vein necrosis virus in two widely separated counties (Ontario and Herkimer) in 2011 suggests that this virus may be more widely distributed in New York and could represent a significant threat to soybean yield. Plans are being developed for statewide survey in 2012. The confirmation in New York of three new diseases (i.e., anthracnose, Bipolaris leaf spot, and smut) of switchgrass, a promising biofuel feedstock, has spawned new research efforts to characterize available switchgrass varieties for potential resistance to these diseases. Relevant research data on useful methods (varieties, cultural practices, and fungicides) for integrated management of Fusarium head blight and mycotoxins of wheat are influencing management choices by New York wheat producers.

Publications

  • Bradley, C.A., E.A. Adee, S.A. Ebelhar, G.C. Bergstrom, R. Dill-Macky, J.J. Wiersma, A.P. Grybauskas, W.W. Kirk, M.P. McMullen, S. Halley, E.A. Milus, L.E. Osborne, K.R. Ruden, and K.A. Wise. 2011. Effects of triazole, strobilurin, and triazole & strobilurin fungicides on Fusarium head blight and associated mycotoxins. Pages 119-121 in Proc. 2011 National Fusarium Head Blight Forum, Hyatt Regency St. Louis at the Arch, St. Louis, MO, Dec 4-6, 2011.
  • Crane, J.M., D.M. Gibson, and G.C. Bergstrom. 2011. Ecology of Bacillus amyloliquifaciens on wheat florets in relation to biological control of FHB/DON. Page 131 in Proc. 2011 National Fusarium Head Blight Forum, Hyatt Regency St. Louis at the Arch, St. Louis, MO, Dec 4-6, 2011.
  • Layton, C.N. and G.C. Bergstrom. 2011. Evaluation of seed treatment fungicides for effect on emergence of switchgrass seedlings in New York, 2010. Plant Disease Management Reports 5:ST011.
  • Waxman, K.D. and G.C. Bergstrom. 2011. Effects of fungicide and insecticide seed treaments on agronomic performance of winter wheat in New York, 2010. Plant Disease Management Reports 5:ST004.
  • Waxman, K.D., G.C. Bergstrom, R.J. Richtmyer III, and R.R. Hahn. 2011. Evaluation of foliar fungicides for control of foliar diseases and Fusarium head blight of winter wheat in New York, 2010. Plant Disease Management Reports 5:CF018.
  • Halley, S., G. Yuen, C. Jochum, B.H. Bleakley, N.K.S. Murthy, K.R. Ruden, K.D. Waxman, G.C. Bergstrom, and L.E. Sweets. 2011. Uniform biological fungicide evaluations for control of Fusarium head blight and deoxynivalenol in wheat. Pages 140-141 in Proc. 2011 National Fusarium Head Blight Forum, Hyatt Regency St. Louis at the Arch, St. Louis, MO, Dec 4-6, 2011.
  • Waxman, K.D. and G.C. Bergstrom. 2011. Evaluation of integrated methods for managing FHB and DON in winter wheat in New York in 2011. Pages 154-158 in Proc. 2011 National Fusarium Head Blight Forum, Hyatt Regency St. Louis at the Arch, St. Louis, MO, Dec 4-6, 2011.
  • Willyerd, K., G. Bergstrom, C. Bradley, R. Dill-Macky, P. Gross, A. Grybauskas, S. Halley, D. Hershman, L. Madden, M. McMullen, G. Milus, L. Osborne, K. Ruden, J.D. Salgado, L. Sweets, S. Wegulo, K. Waxman, K. Wise, and P. Paul. 2011. Pages 161-166 in Proc. 2011 National Fusarium Head Blight Forum, Hyatt Regency St. Louis at the Arch, St. Louis, MO, Dec 4-6, 2011.
  • Waxman, K.D., G.C. Bergstrom, R.J. Richtmyer III, and R.R. Hahn. 2011. Evaluation of integrated methods for management of Fusarium head blight and foliar diseases of winter wheat in New York, 2010. Plant Disease Management Reports 5:CF019.
  • Gibson, D.M., B.C. King, M.L. Hayes, and G.C. Bergstrom. 2011. Plant pathogens as a source of diverse enzymes for lignocellulose digestion. Current Opinion in Microbiology 14:1-7. DOI 10.1016/j.mib.2011.04.002.
  • King, B.C., K.D. Waxman, N.V. Nenni, L.P. Walker, G.C. Bergstrom, and D.M. Gibson. 2011. Arsenal of plant cell wall degrading enzymes reflects host preferences among plant pathogenic fungi. Biotechnology for Biofuels 4:4. doi:10.1186/1754-6834-4-4.
  • Layton, C.N. and G.C. Bergstrom. 2011. Outbreaks of smut caused by Tilletia maclaganii on switchgrass in New York and Pennsylvania. Plant Disease 95:1587. DOI: 10.1094/PDIS-05-11-0401.
  • Miller-Garvin, J.E., Hansen, J.L., Ehlke, N.J., Papadopoulos, Y.A., Smith, R.R., Bergstrom, G.C., Wunsch, M.J., Kalb, D.W., Tillapaugh, B.P., Crawford, J.L., and Viands, D.R. 2011. Improving birdsfoot trefoil for resistance to Fusarium wilt. Crop Science 51: 585-591. doi: 10.2135/cropsci2010.04.0232.
  • Muimba-Kankolongo, A. and G.C. Bergstrom. 2011. Reduced stalk rot development in resistant maize is associated with restricted development of Colletotrichum graminicola in pith tissues. Journal of Phytopathology 159:329-341. DOI: 10.1111/j.1439-0434.2010.01766.x.
  • Schmale, D.G. III, A.K. Wood-Jones, C. Cowger, G.C. Bergstrom, and C. Arellano. 2011. Trichotechene genotypes of Gibberella zeae from winter wheat fields in the Eastern United States. Plant Pathology: (4 March 2011) DOI: 10.1111/j.1365-3059.2011.02443.x.
  • Waxman, K.D. and G.C. Bergstrom. 2011. First report of a leaf spot caused by Bipolaris oryzae on switchgrass in New York. Plant Disease 95:1192. DOI: 10.1094/PDIS-03-11-0231.
  • Waxman, K.D. and G.C. Bergstrom. 2011. First report of anthracnose caused by Colletotrichum caudatum on indiangrass in New York. Plant Disease 95:1189. DOI: 10.1094/PDIS-03-11-0163.
  • Waxman, K.D. and G.C. Bergstrom. 2011. First report of anthracnose caused by Colletotrichum navitas on switchgrass in New York. Plant Disease 95:1032. DOI: 10.1094/PDIS-03-11-0164.
  • Wunsch, M.J. and G.C. Bergstrom. 2011. Genetic and morphological evidence that Phoma sclerotioides, causal agent of brown root rot of alfalfa, is composed of a species complex. Phytopathology 101: 594-610.
  • Bergstrom, G.C., K.D. Waxman, C.A. Bradley, A.L. Hazelrigg, D.E. Hershman, M. Nagelkirk, L.E. Sweets, and S.N. Wegulo. 2011. Effects of local corn debris management on FHB and DON levels in seven U.S. wheat environments in 2011. Page 125-126 in Proc. 2011 National Fusarium Head Blight Forum, Hyatt Regency St. Louis at the Arch, St. Louis, MO, Dec 4-6, 2011.


Progress 10/01/09 to 09/30/10

Outputs
OUTPUTS: A multiple year alfalfa variety experiment was established in northern New York in a field infested with five biotypes of Phoma sclerotioides for the purpose of determining whether certain genotypes persist and yield better than others in the presence of the brown root rot pathogen. We completed a three-year microplot study in 15 New York winter wheat fields to assess the effects of within field corn debris on Fusarium head blight and deoxynivalenol toxin (DON). In only five of the 15 fields were FHB and/or DON significantly higher in corn debris-containing microplots than in control microplots. For the majority of fields, background atmospheric spore load and environmental favorability appeared to be more important determinants of mycotoxin contamination than the presence or absence of corn debris. Foliar fungicides were tested on winter wheat in 2010 under inoculation with Fusarium graminearum. Significant reduction of FHB and DON occurred consistently only with the triazole fungicides Caramba and Prosaro. More than 400 pre-commercial corn hybrids were evaluated for silk-channel resistance to Gibberella ear rot and moderately resistant phenotypes (i.e., reduced colonization of the ear) were observed over a broad range of relative maturity groups. Foliar fungicides (Headline and Quilt) were evaluated in treated strips in commercial fields of grain corn in New York under a range of natural disease intensities; fungicide application resulted in an economic return over nontreated only in fields with significant severity of gray leaf spot in the nontreated check plots. PARTICIPANTS: Individuals: P.I.: G.C. Bergstrom (plan, conduct, and analyze) Research Support Specialist: Katrina Waxman (plan conduct and analyze) Graduate Research Assistant: Michael Wunsch (inoculated alfalfa nursery) Collaborations: Cornell Department of Crop and Soil Science (R.R. Hahn and R. J. Richtmyer) Cornell Department of Plant Breeding and Genetics (J. Hansen, M.E. Sorrells, D. Benscher) Cornell Cooperative Extension Educators (especially Alex Wright, Keith Severson, James Kingston, Mike Stanyard, Carl Albers) Industry:Pioneer HiBred Seeds, Syngenta, BASF, Bayer Crop Protection USDA-US Wheat and Barley Scab Research Initiative TARGET AUDIENCES: Field crop producers, crop consultants, extension educators, and agribusiness in New York. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The alfalfa brown root rot nursery established in northern New York, the first nursery of it type in eastern North America, should identify for plant breeders whether some alfalfa genotypes express useful levels of resistance or tolerance to brown root rot in a climatic zone where this disease reduces plant survival and yield. The mycotoxin-reducing advantage of avoiding corn debris in wheat fields was a significant risk factor for increased mycotoxin contamination in only 5 out of 15 wheat fields studied. Planting of partially resistant wheat varieties remains the single most useful tactic for wheat producers to reduce their mycotoxin risk, but the foliar fungicides Caramba and Prosaro present additional tools for integrated management of toxin to acceptable levels. New York data and recommendations for integrated management of Fusarium head blight were updated on the Scab Smart (www.scabsmart.org) in order to make wheat producers aware of their best options. Fungicides are more wisely applied based on results of scouting for early disease or use a weather-driven risk assessment. Gibberella ear rot is one of the most significant corn production and quality problems in New York; the occurrence of moderate resistance in proprietary genotypes suggests that deployment of resistant hybrids might provide a partial solution to the problem in future years. Based on preliminary experiments in commercial fields, routine foliar fungicide application to grain corn does not appear to be economical in the absence of significant disease occurrence; much more testing needs to be done under a range of conditions.

Publications

  • Bergstrom, G.C., K.D. Waxman, D.G. Schmale III, C.A. Bradley, L.E. Sweets, S.N. Wegulo, and M.D. Keller. 2010. Effects of within-field corn debris in microplots on FHB and DON in eleven U.S. wheat environments in 2010. Pages 69-70 in Proc. 2010 National Fusarium head Blight Forum, Hyatt Regency Milwaukee, Milwaukee, WI, Dec 7-9, 2010.
  • Crane, J.M., D.M. Gibson, and G.C. Bergstrom. 2010. Ecology of Bacillus amyloliquifaciens on wheat florets in relation to biological control of FHB/DON. Pages 77-78 in Proc. 2010 National Fusarium head Blight Forum, Hyatt Regency Milwaukee, Milwaukee, WI, Dec 7-9, 2010.
  • Keller, M.D., D.G. Schmale III, K.D. Waxman, and G.C. Bergstrom. 2010. Tracking released clones of Gibberella zeae within wheat and barley fields. Page 51 in Proc. 2010 National Fusarium head Blight Forum, Hyatt Regency Milwaukee, Milwaukee, WI, Dec 7-9, 2010.
  • Waxman, K.D. and G.C. Bergstrom. 2010. Evaluation of integrated methods for managing FHB and DON in winter wheat in New York. Pages 104-107 in Proc. 2010 National Fusarium head Blight Forum, Hyatt Regency Milwaukee, Milwaukee, WI, Dec 7-9, 2010.
  • Willyerd, K., L. Madden, M. McMullen, S. Wegulo, B. Bockus., L. Sweets, C. Bradley, K. Wise, D. Hershman, G. Bergstrom, A. Grybauskas, L. Osborne, P. Esker, and P. Paul. 2010. Pages 109-110 in Proc. 2010 National Fusarium head Blight Forum, Hyatt Regency Milwaukee, Milwaukee, WI, Dec 7-9, 2010.
  • Wunsch, M.J., K.A. Bassendowski, G.C. Bergstrom, and B.D. Gossen. 2010. Incidence of foliar infection of alfalfa by Phoma medicaginis and P. sclerotioides in Saskatchewan, New York, and Vermont in 2008 and 2009. Can. Plant Dis. Surv. 90:116-118. Available at http://www.cps-scp.ca/cpds.shtml
  • Waxman, K.D., G.C. Bergstrom, R.J. Richtmyer III, and R.R. Hahn. 2010. Effects of fungicide and insecticide seed treaments on agronomic performance of winter wheat in New York, 2009. Plant Disease Management Reports 4:ST001.
  • Waxman, K.D., G.C. Bergstrom, R.J. Richtmyer III, and R.R. Hahn. 2010. Evaluationof integrated methods for management of Fusarium head blight and foliar diseases of winter wheat in New York, 2009. Plant Disease Management Reports 4:CF016.
  • Waxman, K.D., G.C. Bergstrom, R.J. Richtmyer III, and R.R. Hahn. 2010. Evaluation of foliar fungicides for control of foliar diseases and Fusarium head blight of winter wheat in New York, 2009. Plant Disease Management Reports 4:CF017.
  • Keller, M.D., K.D. Waxman, G.C. Bergstrom, and D.G. Schmale III. 2010. Local distance of wheat spike infection by released clones of Gibberella zeae disseminated from infested corn residue. Plant Dis. 94:1151-1155.


Progress 01/01/09 to 12/01/09

Outputs
OUTPUTS: Activities included: 1. biological and phylogenetic analysis of isolates of Phoma sclerotioides, 2. field nurseries to evaluate resistance of alfalfa varieties to P. sclerotioides, 3. survey and characterization of fungi causing foliar infection of alfalfa, 4. on-farm microplot experiments to assess role of corn debris in epidemics of Fusarium head blight of wheat, 5. monitoring of soybean plots for rust and other foliar diseases, 6. Field evaluation of wheat varieties, biological controls, and foliar fungicides for management of Fusarium head blight, 7. evaluation of corn hybrids for resistance to Gibberella ear rot, 8. survey of bioenergy feedstock grasses for diseases, 9. field nurseries for evaluation of wheat varieties for resistance to fungal leaf spots and soilborne viruses, and 10. training of three Ph.D. students. Events included:Field Crop Dealer Meetings, Great Lakes Wheat Consortium, Cooperative Extension In-Service, NCERA-184 and -208 meetings, Agronomy Field Day, Small Grains Field Day, Seed Growers Field Day, Bioenergy Crop Field Days, Field Crops Program Work Team meetings, Bioenergy Feedstocks Advisory Committee meetings, Corn Congresses, Soybean and Small Grains Congresses, National Fusarium Head Blight Forum, National Soybean Rust Symposium, Small Grains Seed Advisory Commitee, weekly contributions to peer and extension listserves, featured speaker on research at more than 20 agricultural extension meetings in 2009. Products included several farmer-useful articles in What's Cropping Up, annual update of Cornell Field Crop Guide, as well as a contribution to new Scab Smart website. PARTICIPANTS: Project participants: P.I.: Gary C. Bergstrom; Research Support Specialists: Katrina Waxman, Stanley Kawamoto; Undergraduate research assistants: Liz Burrichter, Wanshu Di; Undergraduate independent study student: Ariel Kwart. Project cooperators: Mary McKellar, Patricia Clement, Sandra Jensen Tracy, Cornell Plant Disease Diagnostic Clinic; Stewart Gray, Donna Gibson, USDA-ARS Robert Holley Center; Larry Walker, Biological and Environmental Engineering, Cornell; Ev Thomas, Miner Research Institute; William Cox, Phil Atkins, Paul Stachowski, Russ Hahn, Crop and Soil Science, Cornell; Mark Sorrells, David Benscher, Don Viands, Julie Hansen, Hilary Mayton, Plant Breeding and Genetics, Cornell; Cornell Cooperative Extension Field Crop Educators (several), and New York farmers (several). Also, Carl Bradley (Univ. of Illinois), Stephen Wegulo (University of Nebraska), Laura Sweets (Univ. of Missouri), David Schmale (Virginia Tech), Albert Tenuta (Ontario Ministry of Agriculture), Pierre Filion (Quebec Ministry of Agriculture), Martin Vandergrinten (USDA-NRCS), Calvin Ernst and Greg Kedzierski (Ernst Conservation Seed Company), Scott Heuchelin (Pioneer DuPont), Ron Willston (GrowMarkFS), and Francois Lachance (Star of the West Milling). This project plays an important role in the training of plant pathology graduate students who conduct thesis research on the biology and management of field crop diseases. Currently this affects four students. TARGET AUDIENCES: Target audiences: Field crop producers, agribusiness representatives, millers and grain buyers, seed producers, certified crop advisers, plant pathologists in other U.S. states and Canadian provinces. Efforts: Training of graduate and undergraduate students in plant pathology research methods. Annual presentation of research results to peers at professional society meetings. Annual curriculum of in-service education, field days, publications and meetings for education of field crops clientele and multipliers about management of crop diseases. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The differentiation of distinct clades of the alfalfa brown root rot fungus and the recent demonstration that alfalfa varieties react differently to at least two of the clades occurring in New York suggest that clades should be identified as part of variety evaluation for brown root rot reaction and this has been shared with alfalfa breeders. Alfalfa producers in areas not affected by brown root rot were urged to avoid importation of hay from regions where brown root rot is common. A low risk of soybean rust infection was communicated to New York producers in 2009, thus eliminating the need to apply rust fungicides to 200,000 acres of soybean in the state. Avoiding corn debris in wheat fields was a significant risk factor for increased mycotoxin contamination in only one out of six wheat fields studied. Therefore I stress in my extension talks and publications that planting of partially resistant wheat varieties remains the single most useful tactic for wheat producers to reduce their mycotoxin risk. New York data and recommendations for integrated management of Fusarium head blight were added to the Scab Smart educational website (www. ag.ndsu.edu/scabsmart/) in order to make wheat producers aware of their best options. We are working closely with seed companies on resistance to Gibberella ear rot in corn; the occurrence of moderate resistance in pre-commercial genotypes suggests that deployment of resistant hybrids might provide a partial solution to the problem in future years.

Publications

  • Willyerd, K., L. Madden, G. Bergstrom, C. Bradley, A. Grybauskas, D. Hershman, M. McMullen, K. Ruden, L. Sweets, S. Wegulo, K. Wise, and P. Paul. 2009. Integrated management of FHB and DON in small grains: 2009 coordinated trials. Pages 95-99 in Proc. 2009 National Fusarium Head Blight Forum, Wyndham Orlando Resort, Orlando, FL, Dec7-9, 2009.
  • Bergstrom, G.C., K.D. Waxman, D.G. Schmale III, C.A. Bradley, L.E. Sweets, S.N. Wegulo, and M.D. Keller. 2009. Effects of within-field corn debris in microplots on FHB and DON in ten U.S. wheat environments in 2009. Page 22 in Proc. 2009 National Fusarium Head Blight Forum, Wyndham Orlando Resort, Orlando, FL, Dec7-9, 2009.
  • Crane, J.M., D.M. Gibson, and G.C. Bergstrom. 2009. Ecology of Bacillus subtilis on wheat florets in relation to biological control of FHB/DON. Page 39 in Proc. 2009 National Fusarium Head Blight Forum, Wyndham Orlando Resort, Orlando, FL, Dec7-9, 2009.
  • Waxman, K.D. and G.C. Bergstrom. 2009. Evaluation of integrated FHB management methods under moderate and severe epidemics in New York. Pages 90-92 in Proc. 2009 National Fusarium Head Blight Forum, Wyndham Orlando Resort, Orlando, FL, Dec7-9, 2009.
  • Hansen, J.L., J. E. Miller-Garvin, G. C. Bergstrom, M. J. Wunsch, D. W. Kalb, B. P. Tillapaugh, J. Crawford, and D. R. Viands. 2009. Breeding birdsfoot trefoil for resistance to Fusarium wilt in New York. Agronomy Abstracts.
  • Wunsch, M.J., and G.C. Bergstrom. 2009. Evidence that Phoma sclerotioides, causal agent of brown root rot of alfalfa, is composed of a species complex. Phytopathology 99:S143.
  • Gossen, B.D, Bassendowski, K.A., Wunsch, M.J., Bergstrom, G.C., and Otani, J. 2009. Diseases on alfalfa in Saskatchewan and Alberta in 2007 and 2008. Can. Plant Dis. Surv. 89:106-107.
  • Waxman, K.D., G.C. Bergstrom, P.M. Atkins, and W.J. Cox. 2009. Evaluation of fungicide and insecticide seed treatments of winter wheat in New York, 2008. Plant Disease Management Reports 3:CF025.
  • Waxman, K.D., G.C. Bergstrom, P.M. Atkins, and W.J. Cox. 2009. Evaluation of chemical and biological seed treatments of winter wheat in New York, 2008. Plant Disease Management Reports 3:CF027.
  • Wunsch, M.J., Kersbergen, R., Tenuta, A.U., Hall, M.H., and Bergstrom, G.C. 2009. First report of brown root rot of alfalfa, caused by Phoma sclerotioides, in Maine, Ontario, and Pennsylvania. Plant Dis. 93:317. DOI: 10.1094/PDIS-93-3-0317C.
  • Wunsch, M.J., Baker, A.H., Kalb, D.W., and Bergstrom, G.C. 2009. Characterization of Fusarium oxysporum f. sp. loti forma specialis nov., a monophyletic pathogen causing vascular wilt of birdsfoot trefoil. Plant Dis. 93: 58-66.
  • King, B.C., Donnelly, M.K., Bergstrom, G.C., Walker, L.P., and Gibson, D.M. 2009. An optimized microplate assay system for quantitative evaluation of plant cell wall degrading enzyme activity of fungal culture extracts. Biotechnol. Bioeng. 102:1033-1044.
  • Waxman, K.D., G.C. Bergstrom, P.M. Atkins, P.J. Stachowski, and W.J. Cox. 2009. Evaluation of cultural, chemical, and biological control methods of winter wheat in New York, 2007-2008. Plant Disease Management Reports 3:CF026.


Progress 10/01/07 to 09/30/08

Outputs
OUTPUTS: Isolates of Phoma sclerotioides, causal fungus of brown root rot of alfalfa, were collected from across North America, and diagnostic PCR conducted with each isolate resulted in a single amplicon of expected size. Isolates varied in cultural characteristics on laboratory media. Multilocus sequence typing data based on five genes indicated that isolates of the fungus are diverse and fall into five or more distinct clades, with two or more clades being represented in each geographic region sampled. Relative pathogenicity of isolates in different clades is currently being assessed. A weekly monitoring program for detection of soybean rust was implemented in 13 widely-distributed, sentinel soybean plots from June to October 2008. No soybean rust was observed. In a field study in six commercial wheat fields in New York in 2008, placement of naturally overwintered corn stalks into microplots resulted in only small increases in the amount of Fusarium infection of wheat heads and corresponding contamination of grain by deoxynivaenol in comparison to microplots without corn residue. Weather conditions were not conducive for Fusarium, so the experiments will be repeated in 2009. In four experiments over 2 years in New York, the application of foliar fungicide to flowering winter wheat plants resulted in no significant yield increases. More than 400 corn hybrids were evaluated for silk-channel resistance to Gibberella ear rot and several were observed to exhibit moderate levels of resistance with reduced colonization of the ears. Dissemination vehicles included referred journal publications, presentations at professional and grower meetings, extension newsletter articles, and email listserve communications with extension educators, agribusiness, and professional colleagues. PARTICIPANTS: P.I.: Gary C. Bergstrom; Research Support Specialists: Katrina Waxman, Stanley Kawamoto; Temporary Service Employees: Alexandra Baker, Wanshu Di, Helen Bergstrom; Graduate Students: Michael Wunsch, Julia Crane, Christine Layton, Brian King; Cooperators: Mary McKellar, Patricia Clement, Cornell; Stewart Gray, Donna Gibson, USDA-ARS; Larry Walker, Biological and Environmental Engineering, Cornell; Ev Thomas, Miner Research Institute; William Cox, Phil Atkins, Paul Stachowski, Russ Hahn, Crop and Soil Science, Cornell; Mark Sorrells, David Benscher, Don Viands, Julie Hansen, Hilary Mayton, Plant Breeding and Genetics, Cornell; and Cornell Cooperative Extension Field Crop Educators (several). This project plays an important role in the training of plant pathology graduate students who conduct thesis research on the biology and management of field crop diseases. Currently this affects four students. TARGET AUDIENCES: Field crop producers; Agribusiness; Extension field crop educators; Plant pathologists in other states PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The revelation that Phoma sclerotioides is genetically diverse and several distinct clades co-occur across the geographic range in North America suggests that pathogenicity may also be variable. There is therefore some risk that alfalfa varieties identified with resistance to some isolates may not be resistant to other isolates. This question is currently being addressed by field and lab research in New York. A low risk of soybean rust infection was communicated to New York producers in 2008, thus eliminating the need to apply rust fungicides to 200,000 acres of soybean in the state. The mycotoxin-reducing advantage of avoiding the presence of corn debris in wheat fields appears to be negligible as Fusarium spores can also come into a wheat fields on air currents. This advantage continues to be quantified under New York wheat production conditions. Wheat producers were made aware of data showing that routine application of fungicide at flowering often does not result in a return on that investment. Fungicides are more wisely applied based on results of scouting for early disease or use a weather-driven risk assessment. Gibberella ear rot is one of the most significant corn production and quality problems in New York; the occurrence of moderate resistance in proprietary genotypes suggests that deployment of resistant hybrids might provide a partial solution to the problem in future years.

Publications

  • Waxman, K.D., and Bergstrom, G.C. 2008. Evaluation of integrated FHB management methods under low disease environments in New York. Pages in Proc. 2008 National Fusarium Head Blight Forum, Crowne Plaza Hotel at Union Station, Indianapolis, IN, December 2-4, 2008.
  • Kawamoto, S.O., G.C. Bergstrom, P.M. Atkins, and W.J. Cox. 2008. The effects of fungicide and insecticide seed treatments and planting date on winter wheat in New York, 2006. Plant Disease Management Reports 2:CF026.
  • Waxman, K.D., S.O. Kawamoto, G.C. Bergstrom, P.M. Atkins, and W.J. Cox. 2008. Evaluation of chemical and biological seed treatments on winter wheat in New York, 2007. Plant Disease Management Reports 2:CF025.
  • Wunsch, M.J., and G.C. Bergstrom. 2008. Genetic structure of North American populations of Phoma sclerotioides, causal agent of brown root rot of alfalfa. Phytopathology 98:S173.
  • Wunsch, M.J., M.A. Dillon, R. Torres, H.F. Schwartz, and G.C. Bergstrom. 2008. First report of brown root rot of alfalfa, caused by Phoma sclerotioides, in Colorado and New Mexico. Plant Dis. 92: 653. DOI: 10.1094/PDIS-92-4-0653A.
  • Bergstrom, G.C., and K.D. Waxman. 2008. Microplots in commercial wheat fields for quantifying the local contribution of Gibberella zeae from natural corn debris to Fusarium head blight and deoxynivalenol accumulation. Pages in Proc. 2008 National Fusarium Head Blight Forum, Crowne Plaza Hotel at Union Station, Indianapolis, IN, December 2-4, 2008.
  • Kawamoto, S.O., Crane, J.M., Gibson, D.M., and Bergstrom. 2008. Ecology of Bacillus subtilis on wheat florets in relation to biological control of FHB/DON. Pages in Proc. 2008 National Fusarium Head Blight Forum, Crowne Plaza Hotel at Union Station, Indianapolis, IN, December 2-4, 2008.
  • Keller, M.D., Schmale, D.G., Waxman, K.D., and Bergstrom, G.C. 2008. Released clones and background inocula of Gibberella zeae contributed to Fusarium head blight in winter cereals in New York and Virginia. Pages in Proc. 2008 National Fusarium Head Blight Forum, Crowne Plaza Hotel at Union Station, Indianapolis, IN, December 2-4, 2008.


Progress 10/01/06 to 09/30/07

Outputs
OUTPUTS: An aggressive weekly monitoring program for detection of Asian soybean rust was implemented in 20 widely-distributed, sentinel soybean plots from June to October 2007. A low risk of soybean rust infection was communicated to New York producers in 2007 through websites, email, newsletters and field days. A cooperative project with Pioneer was begun to assess corn hybrids for their resistance to Gibberella ear rot. Surveys for brown root rot in alfalfa were expanded with cooperators to Maine, Pennsylvania, and Ontario, Canada. Alfalfa producers in a wide area of the Northeast (New York through New England) were made aware that their fields were at risk from winterkill losses associated with the widespread presence of the pathogen causing brown root rot. A Cornell press release on our brown root rot findings in November 2007 was picked up by the Associated Press and resulted in nationwide media coverage including many newspapers, radio and television coverage, and web news. PARTICIPANTS: P.I.: Gary C. Bergstrom; Research Support Specialists: Katrina Waxman, Stanley Kawamoto; Temporary Service Employees: Alexandra Baker, Lelde Taimina; Graduate Students: Michael Wunsch Cooperators: Mary McKellar, Plant Pathology, Cornell; William Cox, Crop and Soil Science, Cornell; Elson Shields, Entomology, Cornell; Mark Sorrells, Plant Breeding, Cornell; Don Viands, Plant Breeding, Cornell; Ev Thomas, Miner Research Institute; Cornell Cooperative Extension Field Crop Educators (several) TARGET AUDIENCES: Field crop producers; Agribusiness

Impacts
Brown root rot of alfalfa, caused by Phoma sclerotioides, was confirmed for the first time in alfalfa production fields in Colorado, Pennsylvania, Maine, New Mexico, and Ontario, Canada, extending the known range of this pathogen in North America further south in the Rocky Mountains and to a large area of the Northeast/ Great Lakes. No soybean rust was observed in New York but knowledge was increased of the occurrence of other soybean foliar diseases in New York. Bacterial pustule, downy mildew, and Septoria brown spot were widely prevalent though not severe. A low risk of soybean rust infection was communicated to New York producers in 2007, thus eliminating the need to apply rust fungicides to 190,000 acres of soybean in the state. Furthermore, the risk of other foliar diseases was also shown to be low in New York soybean. Approximately 500 corn hybrids were evaluated for silk-channel resistance to Gibberella ear rot and several were observed to exhibit moderate levels of resistance with reduced colonization of the ears. Gibberella ear rot is one of the most significant corn production and quality problems in New York; the occurrence of moderate resistance in proprietary genotypes suggests that deployment of resistant hybrids might provide a partial solution to the problem in future years.

Publications

  • Wunsch, M.J., R.R. Schindelbeck, H.M. van Es, and G.C. Bergstrom. 2007. Distribution, impact, and soil environment of Phoma sclerotioides in Northeastern alfalfa fields. Plant Dis. 91:1293-1304.
  • DelPonte, E.M., J.M.C. Fernandes, and G.C. Bergstrom. 2007. Influence of growth stage on Fusarium head blight and deoxynivalenol production in wheat. J. Phytopathology DOI:10.1111/j.1439-0434.2007.01281.x.
  • Schmale, D. G. III, and G.C. Bergstrom. 2007. The aerobiology and population genetic structure of Gibberella zeae. Plant Health Progress DOI:10.1094/PHP-2007-0726-04-RV.
  • Bennett, R.S., M.G. Milgroom, R. A. Sainudiin, B.M. Cunfer, and G.C. Bergstrom. 2007. Relative contribution of seed-transmitted inoculum to foliar populations of Phaeosphaeria nodorum. Phytopathology 97: 584-591.
  • Pryor, S.W., D.M. Gibson, G.C. Bergstrom, and L.P. Walker. 2007. Minimization of between-well sample variance of antifungal activity using a high throughput screening microplate bioassay. BioTechniques 42:168-172. Doi 10.2144/000112328.
  • Bergstrom, G.C., and D.G. Schmale. 2007. Aerobiology of Gibberella zeae: Whence come the spores for Fusarium head blight? Pages 70-71 in Proc. 2007 National Fusarium Head Blight Forum, The Westin Crown Center, Kansas City, Missouri, December 2-4, 2007.
  • Keller, M.D., K.D. Duttweiler, D.G. Schmale, and G.C. Bergstrom. 2007. Contribution of within-field inoculum sources to Fusarium head blight in wheat. Page 98 in Proc. 2007 National Fusarium Head Blight Forum, The Westin Crown Center, Kansas City, Missouri, December 2-4, 2007.
  • Wunsch, M.J., A.H. Baker, and G.C. Bergstrom. 2007. Characterization of Fusarium oxysporum isolates causing rapid wilt of birdsfoot trefoil by vegetative compatibility and by sequence analysis at three loci. Phytopathology 97: S125 (Abstr.)
  • Dennis, J.S., M.G. Dennis, and G.C. Bergstrom. 2007. Evaluation of foliar fungicides for soybean disease management in New York, 2006. Plant Disease Management Reports 1:FC115.


Progress 01/01/06 to 12/31/06

Outputs
In populations of Gibberella zeae collected from the atmosphere over 3 years as well as from infected wheat spikes collected in 2006, the predominant trichothecene mycotoxin genotype was one that encodes deoxynivalenol (DON) plus the acetylated derivative, 15-ADON. New York populations showed more than 95 percent 15-ADON genotypes as compared to less than 5 percent 3-ADON genotypes; and the nivalenol genotype (NIV) was not found. The random spatial pattern of 3-ADON and 15-ADON genotypes found in infected wheat fields suggested that inoculum was introduced to wheat spikes from a well-mixed population of spores in the atmosphere. An aggressive weekly monitoring program for detection of Asian soybean rust was implemented in 19 widely-distributed, sentinel soybean plots from June to October 2006. No soybean rust was observed but knowledge was increased of the occurrence of other soybean foliar diseases in New York. Bacterial pustule, downy mildew, and Septoria brown spot were widely prevalent while bacterial blight, frogeye leaf spot and Alternaria leaf spot were observed in certain fields. Soybean cyst nematode was not found in any of the 19 sentinel fields, thus its presence in NY has never been confirmed. The complete intergenic spacer region and portions of two other genes were sequenced for 28 isolates of the trefoil-wilt Fusarium oxysporum, and the sequences were compared to corresponding sequences from F. oxysporum nonpathogenic to trefoil, including F. oxysporum pathogenic to other hosts. The results indicate that the trefoil-wilt F. oxysporum populations found in New York and Vermont production fields are very closely related to each other but genetically distinct from other F. oxysporum.

Impacts
Brown stem rot, sudden death syndrome, frogeye leaf spot and Alternaria leaf spot of soybean were each documented in New York for the first time in 2006. Soybean cyst nematode apparently does not yet occur in New York based on a survey of 19 fields in 2006. The more highly toxigenic, nivalenol-producing strains of Gibberella zeae were not found to occur in a survey of New York wheat fields -- good news for the food safety of flour and wheat products from New York grain.

Publications

  • Schmale, D.G. III. 2006. The aerobiology and population genetic structure of Gibberella zeae. Ph.D. Dissertation, Cornell University, Ithaca, NY.
  • Schmale, D.G. III, J.F. Leslie, K.A. Zeller, A.A. Saleh, E.J. Shields and G.C. Bergstrom. 2006. Genetic structure of atmospheric populations of Gibberella zeae. Phytopathology 96:S104 (Abstr.)
  • Wunsch, M.J., A.H. Baker, R.C. Larsen and G.C. Bergstrom. 2006. Distribution and prevalence of brown root rot of forage legumes in the northeastern United States. Phytopathology 96: S125 (Abstr.)
  • Wunsch, M.J. and G.C. Bergstrom. 2006. Characterization of Fusarium oxysporum causing rapid wilt of birdsfoot trefoil in New York and Vermont. Phytopathology 96: S125 (Abstr.)
  • Kawamoto, S.O., G.C. Bergstrom, B.T. Esposito, W.J. Cox, D.J. Otis and P.M. Atkins. 2006. Effects of seed treatments on seed-transmitted Stagonopsora nodorum blotch and agronomic performance of winter wheat, 2004. Fungicide and Nematicide Tests 61:ST028.
  • Schmale, D.G. III, J.F. Leslie, K.A. Zeller, A.A. Saleh, E.J. Shields and G.C. Bergstrom. 2006. Genetic structure of atmospheric populations of Gibberella zeae. Phytopathology 96: 1021-1026.
  • Cadle-Davidson, L., M.E. Sorrells, S.M. Gray and G.C. Bergstrom. 2006. Identification of small grain genotypes resistant to Wheat spindle streak mosaic virus. Plant Dis. 90: 1045-1050.
  • Cadle-Davidson, L., M.E. Sorrells, S.M. Gray and G.C. Bergstrom. 2006. Identification of small grain genotypes resistant to Soilborne wheat mosaic virus. Plant Dis. 90:1039-1044.
  • Schmale, D.G. III, E.J. Shields and G.C. Bergstrom. 2006. Night-time spore deposition of the fusarium head blight pathogen, Gibberella zeae, in rotational wheat fields. Can. J. Plant Pathol. 28:1-9.
  • Schmale, D.G. III., A.K. Wood-Jones, G.C. Bergstrom and C. Cowger. 2006. Spatial patterns of trichothecene genotypes of Gibberella zeae in wheat fields. Page 140 in Proc. 2006 National Fusarium Head Blight Forum, Sheraton Imperial Hotel, Research Triangle Park, North Carolina, December 10-12, 2006.
  • Schmale, D.G. III., A.K. Wood-Jones and G.C. Bergstrom. 2006. Trichothecene genotypes in atmospheric populations of Gibberella zeae. Page 141 in Proc. 2006 National Fusarium Head Blight Forum, Sheraton Imperial Hotel, Research Triangle Park, North Carolina, December 10-12, 2006.


Progress 01/01/05 to 12/31/05

Outputs
Survey of New York State alfalfa fields for brown root rot was intensified in 2005. The causal fungus, Phoma sclerotioides, has now been shown to be widely distributed across the state. Individual fields sampled in early spring had incidences of infected plants as high as 75 percent. An aggressive weekly monitoring program for detection of Asian soybean rust was implemented in 10 widely-distributed, sentinel soybean plots from June to September 2005. This was supplemented by collection and PCR assay of rainwater from several sites in September through November. No soybean rust was observed. We conducted a genetic (AFLP) analysis of atmospheric populations of Gibberella zeae collected above crop canopies over a 4 year period at the Musgrave Farm in Aurora, NY. Genotypic diversity was high and nearly all of the isolates collected were unique AFLP haplotypes. High genotypic diversity was maintained on a temporal scale of collection of isolates over consecutive calender dates, consecutive day and night periods, and during two-hour sampling intervals at night. When the New York populations were compared to those from other U.S. locations, the observed difference in genetic diversity among the populations was quite small, suggesting significant genetic exchange across the continent.

Impacts
Brown root rot of alfalfa is now documented as a widely prevalent disease of alfalfa in the Northeast which raised the unanswered question of whether it is decreasing the health and longevity of forage stands to any significant extent. Our findings on the aerobiology and population structure of Gibberella zeae in the air above crop canopies suggest that atmospheric populations are an abundant, well-mixed, and diverse source of inoculum for regional epidemics of Fusarium head blight in cereals and Gibberella ear rot of corn.

Publications

  • Maldonado-Ramirez, S.L, D.G. Schmale III, E.J. Shields, and G.C. Bergstrom. 2005. The relative abundance of viable spores of Gibberella zeae in the planetary boundary layer suggests the role of long-distance transport in regional epidemics of Fusarium head blight. Agricultural and Forest Meteorology 132: 20-27.
  • Schmale, D.G. III, Q.A. Arntsen, and G.C. Bergstrom. 2005. The forcible discharge distance of ascospores of Gibberella zeae. Can. J. Plant Pathol. 27: 376-382.
  • Schmale, D.G. III, D. A. Shah, and G.C. Bergstrom. 2005. Spatial patterns of viable spore deposition of Gibberella zeae in rotational wheat fields. Phytopathology 95: 472-479.
  • Schmale, D.G. III, D. A. Shah, and G.C. Bergstrom. 2005. Spatial patterns of viable spore deposition of the ear rot pathogen, Gibberella zeae, in first-year corn fields. Can. J. Plant Pathol. 27: 225-233.
  • Bergstrom, G.C. and D.G. Schmale III. 2005. Aerobiology and regional epidemiology of Gibberella zeae. Page 76 in Proc. 4th Canadian Workshop on Fusarium Head Blight. Ottawa Congress Centre. Ottawa, Canada, November 1-3, 2005.
  • Cadle-Davidson, L., G.C. Bergstrom, and T.S. Cox. 2005. Susceptibility of perennial small grains to Soilborne wheat mosaic virus and Wheat spindle streak mosaic virus. Online. Plant Health Progress doi:10.1094/PHP-2005-1130-01-BR.
  • Schmale, D.G. III, J.F. Leslie, R.L. Bowden, K.A. Zeller, A.A. Saleh, E.J. Shields, and G.C. Bergstrom. 2005. Genetic structure of atmospheric populations of Gibberella zeae. Page 149 in Proc. 2005 National Fusarium Head Blight Forum, Hilton Milwaukee City Center, Milwaukee, Wisconsin, December 11-13, 2005.
  • Schmale, D.G. III, J.F. Leslie, A.A. Saleh, E.J. Shields, and G.C. Bergstrom. 2005. Temporal scales of genetic diversity within New York atmospheric populations of Gibberella zeae. Page 150 in Proc. 2005 National Fusarium Head Blight Forum, Hilton Milwaukee City Center, Milwaukee, Wisconsin, December 11-13, 2005.
  • Bennett, R.S. 2005. Dominant sources of inoculum in the Phaeosphaeria nodorum-wheat pathosystem. Ph.D. Thesis. Cornell University. 111 pp.
  • Muimba-Kankalongo, A. and G.C. Bergstrom. 2005. Restricted early development of Colletotrichum graminicola in maize tissues resistant to anthracnose stalk rot. Phytopathology 95:S72.
  • Schmale, D.G. III and G.C. Bergstrom. 2005. The aerobiology and population genetic structure of Gibberella zeae. Phytopathology 95:S127.


Progress 01/01/04 to 12/31/04

Outputs
As a result of a statewide survey of alfalfa fields in 2004, brown root rot, caused by the fungus Phoma sclerotioides, was confirmed for the first time in individual fields in Steuben and St. Lawrence Counties, as well as in additional fields in Clinton Co. where the disease was first confirmed in 2003. In a foliar fungicide and bioprotectant field trial against wheat scab, only the combined treatment with fungicide JAU6476 and Bacillus subtilis strain TrigoCor 1448 reduced deoxynivalenol contamination of harvested grain below the advisory level of 2 ppm. Using small glass chambers, we determined that ascospores of Gibberella zeae are forcibly discharged an average of 4-5 mm in still air. We estimated spore settling velocities and determined that only a very small percentage of discharged spores are likely to become airborne under night-time atmospheric conditions, but a significant percentage are likely to surpass the laminar boundary layer of air during day-time atmospheric conditions. We completed three years of assessing the deposition of viable spores of Gibberella zeae in commercial wheat and corn fields; we found that deposition occurs predominantly during night-time hours and that the spatial patterns of deposition are predominantly random, as would be expected for gravitational settling from well-mixed atmospheric inoculum.

Impacts
The confirmation of Phoma sclerotioides in forage plants in three New York Counties in 2004 suggests that brown root rot may occur more widely and be contributing to decreased overwintering of alfalfa and other forage stands in the Northeast as it currently does in the Northwestern U.S.

Publications

  • Schmale, D.G. III, and G.C. Bergstrom. 2004. Spore deposition of the ear rot pathogen, Gibberella zeae, inside corn canopies. Can. J. Plant Pathol. 26:591-595. Cadle-Davidson, L., and G.C. Bergstrom. 2004. The effects of postplanting environment on the incidence of soilborne viral diseases in winter cereals. Phytopathology 94: 527-534.
  • Schmale, D.G. III, and G.C. Bergstrom. 2004. Airborne propagules of Gibberella zeae: Techniques for monitoring spore release and viability. Phytopathology 94:S93. Publication no. P-2004-0632-AMA.
  • Cadle-Davison, L. and G.C. Bergstrom. 2004. Chemical seed treatment for control of soilborne viruses in laboratory soil cores and in New York fields, 2002 and 2003. Fungicide and Nematicide Tests 59:ST001. Kawamoto, S.O., G.C. Bergstrom, W.J. Cox, and D.J. Otis. 2004. Evaluation of foliar fungicides and bioprotectants for control of Fusarium head blight of winter wheat in New York, 2003. Fungicide and Nematicide Tests 59:CF007.
  • Kawamoto, S.O., G.C. Bergstrom, W.J. Cox, and D.J. Otis. 2004. Effects of seed treatments on seed-transmitted Stagonospora nodorum blotch and agronomic performance of winter wheat, 2003. Fungicide and Nematicide Tests 59:ST021.
  • Cadle-Davidson, L., T. Nerad, S.M. Gray, and G.C. Bergstrom. 2004. Wheat spindle streak mosaic virus replicates in the saprophytic protozoan Colpoda. Phytopathology 94:S163. Publication no. P-2004-0005-NEA.
  • Davidson, L.E., G.C. Bergstrom,., W. Huth, and M. Bonnefoy. 2004. Virus diseases of Secale cereale: Wheat spindle streak mosaic. Page 542 in: H. Lapierre and P.-A. Signoret ed., Viruses and Virus Diseases of Poaceae, INRA, Paris, France.
  • Davidson, L.E., G.C. Bergstrom,., W. Huth, and M. Bonnefoy. 2004. Virus diseases of Triticosecale: Wheat spindle streak mosaic. Page 616 in: H. Lapierre and P.-A. Signoret ed., Viruses and Virus Diseases of Poaceae, INRA, Paris, France.
  • Rubies-Autonell, C., L.E. Davidson, and G.C. Bergstrom. 2004. Virus diseases of Triticum durum.: Wheat spindle streak mosaic. Pages 613-614 in: H. Lapierre and P.-A. Signoret ed., Viruses and Virus Diseases of Poaceae, INRA, Paris, France.
  • Sohn, A., P.A. Signoret, L.E. Davidson, and G.C. Bergstrom. 2004. Virus diseases of Triticum spp.: Wheat spindle streak mosaic. Pages 597-599 in: H. Lapierre and P.-A. Signoret ed., Viruses and Virus Diseases of Poaceae, INRA, Paris, France. Bergstrom, G.C. 2004. The promise and challenge of employing biological control in the integrated management of Fusarium head blight. Page 291 in: Proc. Second International Symposium on Fusarium Head Blight. Wyndham Orlando Resort, Orlando, FL, December 11-15, 2004.
  • Schmale, D.G. III, Q.A. Arntsen, and G.C. Bergstrom. 2004. The forcible discharge distance of ascospores of Gibberella zeae. Page 515 in: Proc. Second International Symposium on Fusarium Head Blight. Wyndham Orlando Resort, Orlando, FL, December 11-15, 2004.
  • Schmale, D.G. III, D.A. Shah, and G.C. Bergstrom. 2004. Spatial patterns of viable spore deposition of Gibberella zeae in wheat and corn fields. Page 514 in: Proc. Second International Symposium on Fusarium Head Blight. Wyndham Orlando Resort, Orlando, FL, December 11-15, 2004.