DEVELOPMENT OF FIELD CROP FUNGICIDE MANAGEMENT GUIDELINES FOR ILLINOIS AND MONITORING FOR FUNGICIDE RESISTANCE

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0213367
• Project Start Date: Oct 1, 2007
• Project End Date: Sep 30, 2012
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIVERSITY OF ILLINOIS
2001 S. Lincoln Ave.
URBANA,IL 61801

Performing Department
CROP SCIENCES

Non Technical Summary
Illinois recently experienced an increase in corn acreage and an increase in conservation tillage practices (Illinois Agricultural Statistics Office, Springfield, IL; Conservation Technology Information Center, West Lafayette, IN). Much of the increased corn acreage was achieved by producing corn on non-rotated fields (corn-on-corn). With increased corn-on-corn and increased conservation tillage practices, the risk for foliar diseases on corn increases. This increased risk for diseases, combined with higher market prices recently observed for corn, may contribute to the profitable use of foliar fungicides on corn, but more research is needed to determine under what circumstances and disease levels this potential profitability can be achieved. Similar to corn, the circumstances and disease levels under which fungicides can be profitable on soybean and winter wheat in Illinois also needs to be determined. Winter wheat growers in Illinois have access to a Fusarium head blight risk assessment tool, which can help them make fungicide application decisions (De Wolf et al., 2003), but more research is needed to determine the accuracy of this disease forecasting model in Illinois.

Animal Health Component

80%

Research Effort Categories

Basic

20%

Applied

80%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
212	2410	1160	100%

Knowledge Area
212 - Pathogens and Nematodes Affecting Plants;

Subject Of Investigation
2410 - Cross-commodity research--multiple crops;

Field Of Science
1160 - Pathology;

Keywords

fungicide management

fungicide resistance

Goals / Objectives
1. Develop fungicide management guidelines for corn, soybean, and winter wheat in Illinois that are based on data from research trials conducted over multiple years and locations throughout the state. 2. Develop strobilurin fungicide baseline sensitivity levels for Cercospora zeae-maydis and C. sojina using isolates that have never been exposed to strobilurin fungicides. 3. Develop a fungicide resistance monitoring program for C. zeae-maydis and C. sojina.

Project Methods
Objective 1. Field trials will be established at university research farms and grower fields in multiple locations throughout the state. Trials will be designed to achieve moderate to high disease pressure. This can be achieved by inoculating plants with specific pathogens, by planting into pathogen-infested crop residue, and by using sprinkler irrigation systems. Multiple cultivars that vary in their resistance to specific diseases will be used in the trials. Disease ratings prior to and after fungicide applications will be collected. Yield and grain quality will also be measured. Standard experimental designs will be used in all of the trials (i.e. randomized complete block) with a minimum of 4 replications. These trials will be repeated over multiple years. Objective 2. Isolates of Cercospora zeae-maydis and C. sojina that have never been exposed to strobilurin fungicides will be collected. This will be done by collecting diseased leaves from fields in which strobilurin fungicides have never been applied. Additionally, isolates will be obtained from other U.S. researchers who have been maintaining historical collections of C. zeae-maydis and C. sojina. In-vitro assays will be conducted to determine the effective concentrations of the fungicides that inhibit 50% of the spores from germinating (EC50 value). Briefly, this involves spreading spore suspensions of each fungal isolate onto media that is amended with different concentrations of the fungicides and determining the percent spores that germinate using a microscope. The fungicides azoxystrobin, pyraclastrobin, and trifloxystrobin will be used in these studies. Objective 3. Isolates of C. zeae-maydis and C. sojina will be collected from fields that have been applied with strobilurin fungicides (i.e. from fungicide research trials and commercial fields that were applied). Using the methods briefly described above, EC50 levels of the fungicides will be determined with these fungal isolates that have been previously exposed. The EC50 levels of these isolates will be compared to the EC50 levels of the baseline isolates to determine if any shifts in sensitivity have occurred. If shifts in sensitivity have been found to occur, then genetic methods will be used to determine which mutations are involved in the shift in fungicide sensitivity.

Progress 10/01/07 to 09/30/12

Outputs
OUTPUTS: Foliar Fungicide Field Trials: A total of seven foliar fungicide trials were conducted on soft red winter wheat in Illinois in 2012. Wheat trials were conducted at Brownstown, Dixon Springs, Monmouth, and Urbana, IL. A total of six foliar fungicide trials were conducted on hybrid corn in Illinois in 2012. The corn trials were conducted at Auburn, Dixon Springs, Monmouth, Perry, Shabbona, and Urbana, IL. A total of three foliar fungicide trials were conducted on soybean in Illinois in 2012. The soybean trials were conducted at Dixon Springs, Monmouth, and Urbana, IL. Fungicide Resistance Studies: Isolates of Cercospora sojina (causal agent of frogeye leaf spot of soybean) were collected from soybean fields in different states that had been sprayed with a quinone outside inhibitor (QoI) fungicide. These isolates were tested for their sensitivity to QoI fungicides using an in vitro laboratory assay, and their sensitivities were compared to the sensitivities of 'baseline' C. sojina isolates. Isolates of Cercospora zeae-maydis and Exserohilum turcicum (causal agents of gray leaf spot and northern leaf blight of corn, respectively) were collected from corn fields that had been applied with a QoI fungicide. These isolates were compared to the sensitivities of baseline isolates. Dissemination of Results: In 2012, results of fungicide trials have been disseminated through oral and poster presentations and written communications (see publications list for written communications). Thirty oral presentations were given in total in several states, including Illinois, Iowa, Indiana, Florida, Kansas, Missouri, Ohio, and Tennessee. Topics in the presentations included foliar and seed-applied fungicides for corn, soybean, and wheat, and fungicide resistance monitoring for soybean and corn pathogens. These meetings included Extension education meetings and scientific meetings. A total of 5 poster presentations were given at scientific meetings. These posters presented information about corn, soybean, and wheat fungicides at the American Phytopathological Society Meeting in Providence, RI and the National Fusarium Head Blight Forum in Orlando, FL. PARTICIPANTS: Individuals that participated in this research were Carl Bradley (Project Director) and Keith Ames (Technical Support). Collaborators with the University of Illinois include staff at the Northwestern Illinois Agronomy Research Center and the Northern Illinois Agronomy Research Center, Mike Vose (Orr Research Center), Stephen Ebelhar (Dixon Springs Agricultural Center), Venkat Chapara (campus), Dianne Pedersen (campus), Fred Kolb (campus), and Guirong Zhang (campus). TARGET AUDIENCES: The target audience includes corn, soybean, and wheat growers in the Midwestern U.S., crop consultants, Extension personnel, state agencies, industry personnel, and university and governmental scientists. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Foliar Fungicide Field Trials: Foliar fungicide trials conducted on winter wheat identified the most efficacious fungicide products for control of Fusarium head blight, the associated mycotoxin deoxynivalenol, stripe rust, leaf rust, and Stagonospora leaf blight. In addition, best management practices for control of Fusarium head blight were identified, and include planting resistant varieties and spraying an efficacious fungicide. Foliar fungicide trials on hybrid corn identified the most efficacious fungicide products for control of gray leaf spot and northern leaf blight. Foliar fungicide trials on soybean identified the most efficacious fungicide products for control of Septoria brown spot, Sclerotinia stem rot, and frogeye leaf spot. Results of these trials were used to develop fungicide guidelines for growers, crop consultants, Extension personnel, and industry personnel. These guidelines will help with fungicide application decision-making, which will help growers be more profitable and will reduce the number of unwarranted fungicide applications. Fungicide Resistance Studies: Isolates of Cercospora sojina were identified in Illinois, Kentucky, Louisiana, Missouri, Tennessee, Alabama, Mississippi, and Arkansas that were resistant to QoI fungicides. Isolates of Cercospora zeae-maydis and Exserohilum turcicum were found to be similar to baseline isolates in their sensitivities to QoI fungicides.

Publications

• Zhang, G.R., Pedersen, D.K., Phillips, D.V. and Bradley, C.A. 2012. Sensitivity of Cercospora sojina isolates to quinone outside inhibitor fungicides. Crop Protection 40:63-68.
• Peltier, A.J., Bradley, C.A., Chilvers, M.I., Malvick, D.K., Mueller, D.S., Wise, K.A. and Esker, P.D. 2012. Biology, yield loss and control of Sclerotinia stem rot of soybean. Online. Journal of Integrated Pest Management doi: http://dx.doi.org/10.1603/IPM11033.
• Weems, J.D., Ames, K.A. and Bradley, C.A. 2012. Field evaluation of foliar fungicides for control of northern corn leaf blight. American Phytopathological Society Annual Meeting Abstracts (www.apsnet.org).
• Chapara, V., Pedersen, D.K., Balint-Kurti, P., Esker, P.D., Robertson, A.E., Paul, P.A. and Bradley, C.A. 2012. Baseline sensitivity of Exserohilum turcicum to the quinone outside inhibitor pyraclostrobin. American Phytopathological Society Annual Meeting Abstracts (www.apsnet.org).
• Ahonsi, M.O., Ames, K.A., Gray, M.E. and Bradley, C.A. 2012. Biomass reduction potentials of a new leaf blight of Miscanthus x giganteus caused by Pithomyces chartarum and screening for effective fungicide control. American Phytopathological Society Annual Meeting Abstracts (www.apsnet.org).
• Willyerd, K.T., Bradley, C.A., Conley, S.P., Esker, P.D., Madden, L.V., Wise, K.A. and Paul, P.A. 2012. Effects of different foliar fungicides and application timings on Stagonospora nodorum leaf blotch in soft red winter wheat: Amultistate study. American Phytopathological Society Annual Meeting Abstracts (www.apsnet.org).
• Ahonsi, M.O., Ames, K.A., Gray, M.E. and Bradley, C.A. 2012. Biomass reducing potential and prospective fungicide control of a new leaf blight of Miscanthus x giganteus caused by Leptosphaerulina chartarum. BioEnergy Research (In Press).
• Zhang, G.R. and Bradley, C.A. 2012. Comparison of quinone outside inhibitor fungicide resistant and sensitive isolates of Cercospora sojina. American Phytopathological Society Annual Meeting Abstracts (www.apsnet.org).
• Frohning, J.R., Ames, K.A., Niblack, T.L. Bond, J.P. and Bradley, C.A. 2012. Evaluation of Rhizoctonia solani and Heterodera glycines interactions on soybean. Phytopathology 102:S5.4.
• Mallowa, S.O., Esker, P., Paul, Bradley, C. and Robertson, A. 2012. Studies on the effect of corn hybrid and foliar fungicide on disease severity and yield in corn in the U.S. Corn Belt. Phytopathology 102:S5.7.
• Bradley, C.A., Zhang, G.R., Ming, R., Zeng, F. Ebelhar, S., Ames, K., Olaya, G., Sierotzki, H., Wullschleger, J., Hershman, D., Kennedy, B., Padgett, B. and Newman, M. 2012. Fungicide resistance in Cercospora sojina: Chapter 2. Proceedings of the Southern Soybean Disease Workers Meeting, March 7-8, 2012, Pensacola Beach, FL.
• Bradley, C.A. 2012. Stripe rust of wheat update. Illinois Pest Management and Crop Development Bulletin, Issue no. 3.
• Bradley, C.A. 2012. Fusarium head blight (scab) of wheat: Risk assessment and management. Illinois Pest Management and Crop Development Bulletin, Issue no. 3.
• Bradley, C.A. 2012. Corn and soybean diseases: Update and outlook. Illinois Pest Management and Crop Development Bulletin, Issue no. 10.
• Bradley, C.A. 2012. Target diseases when considering foliar fungicides for corn. Illinois Pest Management and Crop Development Bulletin, Issue no. 12.
• Bradley, C.A. 2012. Do dry-weather crops still need fungicides Illinois Pest Management and Crop Development Bulletin, Issue no. 16.
• Bradley, C.A. 2012. Influence of management practices on Fusarium mycotoxins in wheat straw. Pages 8-9, Proceedings of the National Fusarium Head Blight Forum, December 4-6, 2012, Orlando, FL.
• McMullen, M., Friskop, A., Jordahl, J., Meyer, S., Bergstrom, G., Bradley, C.A., Dill-Macky, R., Smith, M., Wiersma, J., Halley, S., Arens, A., Milus, G., Ruden, K. and Schatz, B. 2012. Uniform fungicide trial results for management of FHB and DON, 2012. Pages 19-20, Proceedings of the National Fusarium Head Blight Forum, December 4-6, 2012, Orlando, FL.
• Willyerd, K., Ames, K., Bergstrom, G., Bradley, C., Cummings, J., Gross, P., Madden, L., Ransom, J., Ruden, K., Salgado, J.D., Sweets, L., Wise, K. and Paul, P. 2012. Uniform FHB integrated management trials: A summary from 2012. Pages 29-33, Proceedings of the National Fusarium Head Blight Forum, December 4-6, 2012, Orlando, FL.
• Bradley, C.A. 2012. Factors considered when making corn foliar fungicide application decisions in Illinois. Online. Journal of Extension 50(3) Article 3RIB7, http://www.joe.org/joe/2012june/rb7.php.
• Bradley, C.A., Wood, A., Zhang, G.R., Murray, J.E., Phillips, D.V. and Ming, R. 2012. Genetic diversity of Cercospora sojina revealed by amplified fragment length polymorphism markers. Canadian Journal of Plant Pathology 34:410-416.
• Willyerd, K.T., Li, C., Madden, L.V., Bradley, C.A., Bergstrom, G.C., Sweets, L.E., McMullen, M., Ransom, J.K., Grybauskas, A., Osborne, L., Wegulo, S.N., Hershman, D.E., Wise, K., Bockus, W.W., Groth, D., Dill-Mackey, R., Milus, E., Esker, P.D., Waxman, K.D., Adee, E.A., Ebelhar, S.E., Young, B.G. and 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.
• Zhang, G.R., Newman, M.A., and Bradley, C.A. 2012. First report of the soybean frogeye leaf spot fungus (Cercospora sojina) resistant to quinone outside inhibitor fungicides in North America. Plant Disease 96:767.

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: Foliar Fungicide Field Trials: A total of seven foliar fungicide trials were conducted on soft red winter wheat in Illinois in 2011. Wheat trials were conducted at Brownstown, Dixon Springs, Monmouth, and Urbana, IL. A total of six foliar fungicide trials were conducted on hybrid corn in Illinois in 2011. The corn trials were conducted at Auburn, Dixon Springs, Monmouth, Perry, Shabbona, and Urbana, IL. A total of seven foliar fungicide trials were conducted on soybean in Illinois in 2011. The soybean trials were conducted at Belleville, Dixon Springs, Monmouth, Perry, Ridgway, Shabbona, and Urbana, IL. Fungicide Resistance Studies: Isolates of Cercospora sojina (causal agent of frogeye leaf spot of soybean) were collected from soybean fields in different states that had been sprayed with a quinone outside inhibitor (QoI) fungicide. These isolates were tested for their sensitivity to QoI fungicides using an in vitro laboratory assay, and their sensitivities were compared to the sensitivities of "baseline" C. sojina isolates. Isolates of Cercospora zeae-maydis and Exserohilum turcicum (causal agents of gray leaf spot and northern leaf blight of corn, respectively) were collected from corn fields that had been applied with a QoI fungicide. These isolates were compared to the sensitivities of baseline isolates. PARTICIPANTS: Individuals that participated in this research were Carl Bradley (Project Director) and Keith Ames (Technical Support). Collaborators with the University of Illinois include Eric Adee (Northwestern Illinois Agronomy Research Center), Lyle Paul (Northern Illinois Agronomy Research Center), Mike Vose (Orr Research Center), Stephen Ebelhar (Dixon Springs Agricultural Center), Venkat Chapara (campus), Dianne Pedersen (campus), Fred Kolb (campus), and Guirong Zhang (campus). TARGET AUDIENCES: The target audience includes corn, soybean, and wheat growers in the Midwestern U.S., crop consultants, Extension personnel, state agencies, industry personnel, and university and governmental scientists. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Foliar Fungicide Field Trials: Foliar fungicide trials conducted on winter wheat identified the most efficacious fungicide products for control of Fusarium head blight, the associated mycotoxin deoxynivalenol, leaf rust, and Stagonospora leaf blight. In addition, best management practices for control of Fusarium head blight were identified, and include planting resistant varieties and spraying an efficacious fungicide. Foliar fungicide trials on hybrid corn identified the most efficacious fungicide products for control of gray leaf spot, northern leaf blight and southern rust. Foliar fungicide trials on soybean identified the most efficacious fungicide products for control of Septoria brown spot, Sclerotinia stem rot, and frogeye leaf spot. Results of these trials were used to develop fungicide guidelines for growers, crop consultants, Extension personnel, and industry personnel. These guidelines will help with fungicide application decision-making, which will help growers be more profitable and will reduce the number of unwarranted fungicide applications. Fungicide Resistance Studies: Isolates of Cercospora sojina were identified in Illinois, Kentucky, Louisiana, Missouri, and Tennessee that were resistant to QoI fungicides. Isolates of Cercospora zeae-maydis and Exserohilum turcicum were found to be similar to baseline isolates in their sensitivities to QoI fungicides. Dissemination of Results: In 2011, results of fungicide trials have been disseminated through oral and poster presentations and written communications (see publications list for written communications). Twenty-three oral presentations were given in total in several states, including Illinois, Indiana, Florida, South Dakota, Iowa, and Missouri. Topics in the presentations included foliar fungicides for corn, soybean, and wheat and fungicide resistance monitoring for soybean and corn pathogens. These meetings included Extension education meetings and scientific meetings. A total of fifteen poster presentations were given at scientific meetings. These posters presented information about corn, soybean and wheat fungicides at the American Phytopathological Society Meeting in Honolulu, HI, the North Central Division of APS Meeting in Omaha, NE, and the National Fusarium Head Blight Forum in St. Louis, MO.

Publications

• Esker, P., Bradley, C., Paul, P. and Robertson, A. 2011. How do we assess crop loss Phytopathology 101:S223.
• Esker, P., Bradley, C., Paul, P. and Robertson, A. 2011. Perception by growers and consultants of the importance of corn diseases. Phytopathology 101:S50.
• Esker, P., Bradley, C., Paul, P. and Robertson, A. 2011. Does one size fit all for delivering corn disease-related information Phytopathology 101:S50.
• Weems, J.D., Ames, K.A. and Bradley, C.A. 2011. Making foliar fungicide applications to corn consistently profitable in Illinois. Phytopathology 101:S189.
• Willyerd, K.T., Bradley, C., Conley, S., Esker, P., Madden, L., Wise, K. and Paul, P. 2011. Efficacy of pre-flag leaf emergence foliar fungicide applications for Stagonospora nodorum blotch management in soft red winter wheat. Phytopathology 101:S191.
• Willyerd, K.T., Bradley, C., Conley, S., Esker, P., Madden, L., Wise, K. and Paul, P. 2011. Revisiting flag leaf-based foliar fungicide application thresholds for Stagonospora nodorum blotch management in soft red winter wheat. Phytopathology 101:S191.
• Chapara, V., Pedersen, D.K., Esker, P., Paul, P.A., Robertson, A.E. Bradley, C.A. 2011. Monitoring Cercospora zeae-maydis sensitivity levels to quinone outside inhibitor fungicides across multiple years. Phytopathology 101:S31.
• Schisler, D.A., Paul, P.A., Boehm, M.J., Bradley, C.A. and Dunlap, C.A. 2011. Antagonist Cryptococcus flavescens OH 182.9 3C colonization of wheat heads when applied with triazole fungicides and the effect on scab. Phytopathology 101:S160.
• Frohning, J.R., Niblack, T.L., Ames, K.A., Bond, J.P. and Bradley, C.A. 2011. Field evaluation of Rhizoctonia solani - Heterodera glycines interactions on soybean. Phytopathology 101:S2.3
• Shelby, R.J., Ames, K.A. and Bradley, C.A. 2011. Effects of pyraclostrobin foliar fungicide and harvest timing on corn stalk health. Phytopathology 101:S2.8
• Bergstrom, G.C., Waxman, K.D., Bradley, C.A., Hazelrigg, A.L., Hershman, D.E., Nagelkirk, M., Sweets, L.E. and Wegulo, S.N. 2011. Effects of local corn debris management on FHB and DON levels in seven U.S. wheat environments in 2011. Proceedings of the 2011 National Fusarium Head Blight Forum, page 119.
• Bradley, C.A. 2011. Assessing the best fungicide application timing for Fusarium head blight and mycotoxin management. Proceedings of the 2011 National Fusarium Head Blight Forum, page 124.
• Bradley, C.A., Adee, E.A., Ebelhar, S.A., Bergstrom, G.C., Dill-Macky, R., Wiersma, J.J., Grybauskas, A.P., Kirk, W.W., McMullen, M.P., Halley, S., Milus, E.A., Osborne, L.E., Ruden, K.R., Wise, K.A., Conley, S. and Esker, P.D. 2011. Effects of triazole, strobilurin, and triazole + strobilurin fungicides on Fusarium head blight and associated mycotoxins. Proceedings of the 2011 National Fusarium Head Blight Forum, pages 125-126.
• Bradley, C.A., Ames, K.A., Dong, Y., Brucker, E.A. and Kolb, F.L. 2011. Influence of Fusarium head blight management practices on mycotoxins in wheat straw. Proceedings of the 2011 National Fusarium Head Blight Forum, pages 127-128.
• Bradley, C.A. and Zhang, G.R. 2011. Detection and management of strobilurin fungicide-resistant strains of the frogeye leaf spot pathogen of soybean. Proceedings of the 2011 University of Illinois Agronomy Day, Urbana, IL, p. 18.
• Bradley, C.A. 2011. Paying for fungicides, or making fungicides pay Proceedings of the 2011 Illinois Corn and Soybean Classic Meeting Series, pp. 2-6.
• Olaya, G., Pearsaul, D., Zhang, G. and Bradley, C. 2011. Evaluation of Cercospora sojina isolates sensitive and resistant to azoxystrobin using a mycelial growth inhibition assay. Phytopathology 101:S132.
• Zhang, G.R. and Bradley, C.A. 2011. Survival of Cercospora sojina on soybean leaves in Illinois. Phytopathology 101:S203.
• Brucker, E.A., Karplus, N.H., Bradley, C.A. and Kolb, F.L. 2011. Evaluation of host plant resistance and fungicide treatments for suppression of Fusarium head blight. Proceedings of the 2011 National Fusarium Head Blight Forum, page 129.
• Willyerd, K., Bergstrom, G., Bradley, C., Dill-Macky, R., Gross, P., Grybauskas, A., Halley, S., Hershman, D., Madden, L., McMullen, M., Milus, G., Osborne, L., Ruden, K., Salgado, J.D., Sweets, L., Wegulo, S., Waxman, K., Wise, K. and Paul, P. Uniform Fusarium head blight integrated management trials: A 2011 update. Proceedings of the 2011 National Fusarium Head Blight Forum, page 161.
• Paul, P.A., Madden, L.V., Bradley, C.A., Robertson, A.E., Munkvold, G.P., Shaner, G., Wise, K.A., Malvick, D.K., Allen, T.W., Grybauskas, A., Vincelli, P. and Esker, P. 2011. Meta-analysis of yield response of hybrid field corn to foliar fungicides in the U.S. corn belt. Phytopathology 101:1122-1132.
• Weems, J.D., Ebelhar, S.A., Chapara, V., Pedersen, D.K., Zhang, G.R. and Bradley, C.A. 2011. First report of charcoal rot caused by Macrophomina phaseolina on sunflower in Illinois. Plant Disease 95:1318.
• Khot, S.D., Bilgi, V.N., del Rio, L.E. and Bradley, C.A. 2011. Identification of Brassica napus lines with partial resistance to Sclerotinia sclerotiorum. Online. Plant Health Progress doi:10.1094/PHP-2010-0422-01-RS.
• Bilgi, V.N., Bradley, C.A., Mathew, F.M., Ali, S., and Rasmussen, J.B. 2011. Root rot of dry edible bean caused by Fusarium graminearum. Online. Plant Health Progress doi: 10.1094/PHP-2011-0425-01-RS.
• Qi, M., Wang, D., Bradley, C.A. and Zhao, Y. 2011. Genome sequence analyses of Pseudomonas savastanoi pv. glycinea and subtractive hybridization-based comparative genomics with nine pseudomonads. PLoS One 6:e16541. Doi: 10.1371/journal.pone.0016451.
• Wise, K.A., Bradley, C.A., Markell, S., Pasche, J., Delgado, J.A., Goswami, R.S. and Gudmestad, N.C. 2011. Sensitivity of Ascochyta rabiei populations to prothioconazole and thiabendazole. Crop Protection 30:1000-1005.
• Ahonsi, M.O, Agindotan, B.O., Gray, M.E. and Bradley, C.A. 2011. First report of basal stem rot and foliar blight caused by Pythium sylvaticum on Miscanthus sinensis in Illinois. Plant Disease 95:616.
• Bradley, C.A. and Pedersen, D.K. 2011. Baseline sensitivity of Cercospora zeae-maydis to quinone outside inhibitor fungicides. Plant Disease 95:189-194.
• Esker, P., Peltier, A., Bradley, C., Chilvers, M., Malvick, D., Mueller, D. and Wise, K. 2011. Management of white mold in soybean. National bulletin printed by the North Central Soybean Research Program.
• Peltier, A.J., Esker, P.D., Bradley, C.A., Robertson, A. and Paul, P.A. 2011. Corn foliar diseases: Identification and management field guide. Multi-state Extension publication. Funded by USDA-NIFA.

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: Foliar Fungicide Field Trials: A total of nine foliar fungicide trials were conducted on soft red winter wheat in Illinois in 2009. Wheat trials were conducted at Brownstown, Carbondale, Dixon Springs, Monmouth, and Urbana, Illinois. A total of six foliar fungicide trials were conducted on hybrid corn in Illinois in 2009. The corn trials were conducted at Auburn, Dixon Springs, Monmouth, Perry, Shabbona, and Urbana, Illinois. A total of seven foliar fungicide trials were conducted on soybean in Illinois in 2009. The soybean trials were conducted at Belleville, Dixon Springs, Monmouth, Perry, Ridgway, Shabbona, and Urbana, Illinois. Fungicide Resistance Studies: Laboratory studies were conducted to develop the baseline sensitivity levels of the pathogens Cercospora zeae-maydis (causes gray leaf spot on corn), Cercospora sojina (causes frogeye leaf spot on soybean), and Exserohilum turcicum (causes northern leaf blight on corn) to strobilurin fungicides. Isolates of C. zeae-maydis, C. sojina, and E. turcicum were obtained that had never been exposed to strobilurin fungicides. The determination of baseline sensitivity values for C. zeae-maydis and C. sojina has been completed, and E. turcicum isolates are still being assayed. In addition, over 100 isolates each of C. zeae-maydis and C. sojina were collected from fields and research trials that had been applied with a strobilurin fungicide from 2008 to 2010. These isolates are currently being assayed to determine their sensitivity level to strobilurin fungicides, which will help determine if the pathogens' are becoming less sensitive to strobilurin fungicides over time. Dissemination of Results: In 2010, results of fungicide trials have been disseminated through oral and poster presentations and written communications (see publications list for written communications). Twenty-five oral presentations were given in Illinois, Indiana, and Ontario, Canada. Topics in the presentations included foliar fungicides for corn, soybean, and wheat and fungicide resistance monitoring for soybean and corn pathogens. These meetings included Extension education meetings and scientific meetings. A total of three poster presentations were given at scientific meetings. These posters presented information about soybean and wheat fungicides at the American Phytopathological Society Meeting in Charlotte, NC and the National Fusarium Head Blight Forum in Milwaukee, WI. PARTICIPANTS: Individuals that participated in this research were Carl Bradley (Project Director) and Keith Ames (Technical Support). Collaborators with the University of Illinois include Eric Adee (Northwestern Illinois Agronomy Research Center), Lyle Paul (Northern Illinois Agronomy Research Center), Mike Vose (Orr Research Center), Stephen Ebelhar (Dixon Springs Agricultural Center), Venkat Chapara (campus), Dianne Pedersen (campus), and Guirong Zhang (campus). In addition, Bryan Young, Southern Illinois University, was a collaborator. TARGET AUDIENCES: The target audience includes corn, soybean, and wheat growers in the Midwestern U.S., crop consultants, Extension personnel, state agencies, industry personnel, and university and governmental scientists. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Foliar Fungicide Field Trials: Foliar fungicide trials conducted on winter wheat identified the most efficacious fungicide products for control of Fusarium head blight, the associated mycotoxin deoxynivalenol, leaf rust, and Stagonospora leaf blight. In addition, best management practices for control of Fusarium head blight were identified, and include planting resistant varieties and spraying an efficacious fungicide. Foliar fungicide trials on hybrid corn identified the most efficacious fungicide products for control of gray leaf spot, northern leaf blight and southern rust. Foliar fungicide trials on soybean identified the most efficacious fungicide products for control of Septoria brown spot, Sclerotinia stem rot, and frogeye leaf spot. Results of these trials were used to develop fungicide guidelines for growers, crop consultants, extension personnel, and industry personnel. These guidelines will help with fungicide application decision-making, which will help growers be more profitable and will reduce the number of unwarranted fungicide applications. Fungicide Resistance Studies: Strobilurin fungicide sensitivity of the baseline C. zeae-maydis isolates range from 0.003 to 0.031 ug/ml, 0.0003 to 0.0025 ug/ml, and 0.0004 to 0.0034 ug/ml for azoxystrobin, pyraclostrobin, and trifloxystrobin, respectively. Strobilurin fungicide sensitivity of the baseline C. sojina isolates range from 0.0029 to 0.0323 ug/ml, 0.00014 to 0.00076 ug/ml, and 0.00018 to 0.00311 ug/ml for azoxystrobin, pyraclostrobin, and trifloxystrobin, respectively. The baseline sensitivity for E. turcicum is still under development.

Publications

• Brucker, E.A., Karplus, N.H., Bradley, C.A. and Kolb, F.L. 2010. Evaluation of host plant resistance and fungicide treatment for suppression of Fusarium head blight. Proceedings of the National Fusarium Head Blight Forum, Milwaukee, WI, p. 75 (Abstract).
• Schisler, D.A., Paul, P., Boehm, M.J., Bradley, C.A. and Dunlap, C.A. 2010. Colonization of wheat heads by antagonist Cryptococcus flavescens OH 182.9 when applied alone or in combination with different concentrations of Prosaro and the effect of Fusarium head blight development in field-grown wheat. Proceedings of the National Fusarium Head Blight Forum, Milwaukee, WI, pp. 98-102.
• Bradley, C.A. 2010. A scabby start with a moldy finish: A look back at the major field crop diseases of 2009. Proceedings of the Illinois Corn and Soybean Classic Meeting Series, pp. 46-51.
• Bradley, C.A., Adee, E.A., Ebelhar, S.A., Dill-Macky, R., Wiersma, J.J., Grybauskas, A.P., Kirk, W.W., McMullen, M.P., Halley, S., Milus, E.A., Osborne, L.E., Ruden, K.R. and Young, B.G. 2010. Multi-state uniform fungicide evaluations for control of Fusarium head blight and associated mycotoxins. Proceedings of the National Fusarium Head Blight Forum, Milwaukee, WI, p. 74 (Abstract).
• Bradley, C.A. and Ames, K.A. 2010. Effect of foliar fungicides on corn with simulated hail damage. Plant Disease 94:83-86.
• Bradley, C.A., Esker, P.D., Paul, P.A. and Robertson, A.E. 2010. Foliar fungicides for corn: Targeting disease. Outreach publication, available on-line at: http://www.ncipmc.org/fieldcrops/corn_fungicides.pdf.
• Bradley, C.A. and Pedersen, D.K. 2010. Baseline sensitivity of Cercospora zeae-maydis to quinone outside inhibitor fungicides. Plant Disease (In Press).
• Willyerd, K.T., Bradley, C., Grybauskas, A., Hershman, D., Madden, L., McMullen, M., Osborne, L., Sweets, L. and Paul, P. 2010. Multi-state evaluation of integrated management strategies for Fusarium head blight and deoxynivalenol in small grain. Phytopathology 100:S137 (Abstract).
• Willyerd, K., Madden, L., McMullen, M., Wegulo, S., Bockus, B., Sweets, L., Bradley, C., Wise, K., Hershman, D., Bergstrom, G., Grybauskas, A., Osborne, L., Esker, P. and Paul, P. 2010. Inoculated field trials for evaluating FHB/DON integrated management strategies. Proceedings of the National Fusarium Head Blight Forum, Milwaukee, WI, pp. 109-110 (Abstract).
• Zhang, G., Phillips, D.V. and Bradley, C.A. 2010. Baseline sensitivity of Cercospora sojina to azoxystrobin, trifloxystrobin, and pyraclostrobin. Phytopathology 100:S145 (Abstract).

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: Foliar Fungicide Field Trials: A total of twelve foliar fungicide trials were conducted on soft red winter wheat in Illinois in 2009. Wheat trials were conducted at Brownstown, Carbondale, Dixon Springs, Monmouth, Perry, Shabbona, and Urbana, IL. A total of eight foliar fungicide trials were conducted on hybrid corn in Illinois in 2009. The corn trials were conducted at Auburn, Dixon Springs, Monmouth, Perry, Shabbona, and Urbana, IL. A total of seven foliar fungicide trials were conducted on soybean in Illinois in 2009. The soybean trials were conducted at Belleville, Dixon Springs, Monmouth, Perry, Ridgway, Shabbona, and Urbana, IL. Fungicide Resistance Studies: Laboratory studies were initiated to develop the baseline sensitivity levels of the pathogens Cercospora zeae-maydis (causes gray leaf spot on corn) and Cercospora sojina (causes frogeye leaf spot on soybean) to strobilurin fungicides. Isolates of C. zeae-maydis and C. sojina were obtained that had never been exposed to strobilurin fungicides. The determination of baseline sensitivity values for C. zeae-maydis has been completed, and C. sojina isolates have nearly been completed. In addition, over 100 isolates each of C. zeae-maydis and C. sojina were collected from fields and research trials that had been applied with a strobilurin fungicide in 2008 and 2009. These isolates will be used in future studies to determine their sensitivity level to strobilurin fungicides, which will help determine if the pathogens are becoming less sensitive to strobilurin fungicides over time. Dissemination of Results: Results of fungicide trials have been disseminated through oral and poster presentations and written communications (see publications list for written communications). Twenty-two oral presentations were given in Illinois, Texas, and two Canadian provinces (Ontario and Quebec). Topics in the presentations included foliar fungicides for corn, soybean, and wheat and fungicide resistance monitoring for soybean and corn pathogens. These meetings included Extension education meetings and scientific meetings. A total of three poster presentations and one oral presentation were given at scientific meetings. These posters presented information about corn, soybean, and wheat fungicides at the International IPM Symposium in Portland, OR, the American Phytopathological Society Meeting in Portland, OR, and the National Fusarium Head Blight Forum in Orlando, FL. PARTICIPANTS: Individuals that participated in this research were Carl Bradley (Project Director) and Keith Ames (Technical Support). Collaborators with the University of Illinois include Eric Adee (Northwestern Illinois Agronomy Research Center), Lyle Paul (Northern Illinois Agronomy Research Center), Mike Vose (Orr Research Center), Stephen Ebelhar (Dixon Springs Agricultural Center), Dianne Pedersen (campus), and Guirong Zhang (campus). In addition, Bryan Young, Southern Illinois University, was a collaborator. TARGET AUDIENCES: The target audience includes corn, soybean, and wheat growers in the Midwestern U.S., crop consultants, Extension personnel, state agencies, industry personnel, and university and governmental scientists. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Foliar Fungicide Field Trials: Foliar fungicide trials conducted on winter wheat identified the most efficacious fungicide products for control of Fusarium head blight, the associated mycotoxin deoxynivalenol, and leaf rust. In addition, best management practices for control of Fusarium head blight were identified, and include planting resistant varieties and spraying an efficacious fungicide. Foliar fungicide trials on hybrid corn identified the most efficacious fungicide products for control of gray leaf spot and common rust. Foliar fungicide trials on soybean identified the most efficacious fungicide products for control of Septoria brown spot and frogeye leaf spot. Results of these trials are being used to develop fungicide guidelines for growers, crop consultants, extension personnel, and industry personnel. These guidelines will help with fungicide application decision-making, which will help growers be more profitable and will reduce the number of unwarranted fungicide applications. Fungicide Resistance Studies: Strobilurin fungicide sensitivity of the baseline C. zeae-maydis isolates range from 0.003 to 0.031 ug/ml, 0.0003 to 0.0025 ug/ml, and 0.0004 to 0.0034 ug/ml for azoxystrobin, pyraclostrobin, and trifloxystrobin, respectively. Baseline sensitivity levels of C. sojina to strobilurin fungicides are still under development.

Publications

• Bradley, C.A. 2009. Managing corn and soybean diseases with fungicides. Proceedings of the 2009 Illinois Corn and Soybean Classic Meeting Series, pp. 28-30.
• Bradley, C.A., Adee, E.A., Ebelhar, S.A., Grybauskas, A.P., Hollingsworth, C.R., Kirk, W.W., McMullen, M.P., Milus, E.A., Osborne, L.E., Ruden, K.R. and Young, B.G. 2009. Application timings of Caramba and Prosaro foliar fungicides for management of FHB and DON. Proceedings of the 2009 National Fusarium Head Blight Forum, Orlando, FL, pp. 34 (Abstract).
• Bradley, C.A., Adee, E.A., Ebelhar, S.A., Grybauskas, A.P., Hollingsworth, C.R., Kirk, W.W., McMullen, M.P., Milus, E.A., Osborne, L.E., Ruden, K.R. and Young, B.G. 2009. Effect of pyraclostrobin applications to wheat at different growth stages on DON concentrations in grain. Proceedings of the 2009 National Fusarium Head Blight Forum, Orlando, FL, pp. 35 (Abstract).
• Bradley, C.A. and Ames, K.A. 2009. Evaluation of foliar fungicides on soft red winter wheat in Urbana, Illinois, 2008. Plant Disease Management Reports 3:CF020.
• Bradley, C.A. and Ames, K.A. 2009. Evaluation of foliar fungicides on corn in Auburn, Illinois, 2008. Plant Disease Management Reports 3:FC001.
• Bradley, C.A. and Ames, K.A. 2009. Evaluation of foliar fungicides on corn in Perry, Illinois, 2008. Plant Disease Management Reports 3:FC002.
• Bradley, C.A. and Ames, K.A. 2009. Evaluation of foliar fungicides on corn in Urbana, Illinois, 2008. Plant Disease Management Reports 3:FC003.
• Bradley, C.A. and Ames, K.A. 2009. Effect of foliar fungicides on corn with simulated hail damage. Phytopathology 99:S15 (Abstract).
• Bradley, C.A., Esker, P.D., Paul, P.A., Robertson, A.E. and Mueller, D.S. 2009. Corn and soybean disease management: Does IPM play a role Proceedings of the 6th International Pest Management Symposium, Portland, OR, pp. 24-25 (Abstract).
• Karplus, N.H., Brucker, E.A., Bradley, C.A. and Kolb, F.L. 2009. Evaluation of host plant resistance and fungicide treatment for suppression of Fusarium head blight. Proceedings of the 2009 National Fusarium Head Blight Forum, Orlando, FL, pp. 129-130 (Abstract).
• Willyerd, K., Madden, L., Bergstrom, G., Bradley, C., Grybauskas, A., Hershman, D., McMullen, M., Ruden, K., Sweets, K., Wegulo, S., Wise, K. and Paul, P. 2009. Integrated management of FHB and DON in small grains: 2009 coordinated trials. Proceedings of the 2009 National Fusarium Head Blight Forum, Orlando, FL, pp. 95-99.

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: Foliar Fungicide Field Trials: A total of six foliar fungicide trials were conducted on soft red winter wheat in Illinois in 2008. Wheat trials were conducted at Brownstown, Carbondale, Dixon Springs, Monmouth, and Urbana, Illinois. A total of ten foliar fungicide trials were conducted on hybrid corn in Illinois in 2008. The corn trials were conducted at Auburn, Belleville, Dixon Springs, Monmouth, Perry, Shabbona, and Urbana, Illinois. A total of ten foliar fungicide trials were conducted on soybean in Illinois in 2008. The soybean trials were conducted at Belleville, Brownstown, Dixon Springs, Monmouth, Perry, Ridgway, Shabbona, and Urbana, Illinois. Fungicide Resistance Studies: Laboratory studies were initiated to develop the baseline sensitivity levels of the pathogens Cercospora zeae-maydis (causes gray leaf spot on corn) and Cercospora sojina (causes frogeye leaf spot on soybean) to strobilurin fungicides. Over 100 isolates each of C. zeae-maydis and C. sojina were obtained that had never been exposed to strobilurin fungicides. These isolates are currently being tested in laboratory trials to determine their sensitivity to strobilurin fungicides. In addition, over 100 isolates each of C. zeae-maydis and C. sojina were collected from fields and research trials that had been applied with a strobilurin fungicide. These isolates will be used in future studies to determine their sensitivity level to strobilurin fungicides, which will help determine if the pathogens' are becoming less sensitive to strobilurin fungicides over time. Dissemination of Results: Results of fungicide trials have been disseminated through oral and poster presentations and written communications (see publications list for written communications). Thirty-nine oral presentations were given in five different states, namely Illinois, Indiana, Iowa, Missouri, and North Dakota, and one Canadian province (Ontario). Topics in the presentations included foliar fungicides for corn, soybean, and wheat and fungicide resistance monitoring for soybean and corn pathogens. These meetings included Extension education meetings and scientific meetings. A total of four poster presentations were given at scientific meetings. These posters presented information about corn and wheat fungicides at the American Phytopathological Society Meeting in Minneapolis, MN and the National Fusarium Head Blight Forum in Indianapolis, IN. PARTICIPANTS: Individuals that participated in this research were Carl Bradley (Project Director) and Keith Ames (Technical Support). Collaborators with the University of Illinois include Eric Adee (Northwestern Illinois Agronomy Research Center), Lyle Paul (Northern Illinois Agronomy Research Center), Mike Vose (Orr Research Center), Stephen Ebelhar (Dixon Springs Agricultural Center), Dianne Pedersen (campus), and Guirong Zhang (campus). In addition, Bryan Young, Southern Illinois University, was a collaborator. TARGET AUDIENCES: The target audience includes corn, soybean, and wheat growers in the Midwestern U.S., crop consultants, Extension personnel, state agencies, industry personnel, and university and governmental scientists. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Foliar Fungicide Field Trials. Foliar fungicide trials conducted on winter wheat identified the most efficacious fungicide products for control of Fusarium head blight, the associated mycotoxin deoxynivalenol, and leaf rust. Foliar fungicide trials on hybrid corn identified the most efficacious fungicide products for control of gray leaf spot and common rust. Foliar fungicide trials on soybean identified the most efficacious fungicide products for control of Septoria brown spot and frogeye leaf spot. Results of these trials are being used to develop fungicide guidelines for growers, crop consultants, extension personnel, and industry personnel. These guidelines will help with fungicide application decision-making, which will help growers be more profitable and will reduce the number of unwarranted fungicide applications. Fungicide Resistance Studies. Baseline sensitivity levels of C. zeae-maydis to strobilurin fungicides have been developed. Specifically, the mean sensitivity level of baseline isolates evaluated was 0.0203, 0.0014, and 0.0024 ug/ml for the strobilurin fungicides azoxystrobin, pyraclostrobin, and trifloxystrobin, respectively. Baseline sensitivity levels of C. sojina to strobilurin fungicides are still under development.

Publications

• Ames, K. and Bradley, C.A. 2008. Evaluation of foliar fungicides on winter wheat in Urbana, Illinois, 2007. Plant Disease Management Reports 2:CF004.
• Ames, K. and Bradley, C.A. 2008. Effect of foliar fungicides on gray leaf spot of corn in Ridgway, Illinois. 2:FC054.
• Bradley, C.A. 2008. Early foliar fungicide applications for wheat. Illinois Pest Management and Crop Development Bulletin, Issue no. 1.
• Bradley, C.A. 2008. Managing Fusarium head blight (scab) of wheat. Illinois Pest Management and Crop Development Bulletin, Issue no. 3.
• Bradley, C.A. 2008. Making profitable fungicide applications in corn. Illinois Pest Management and Crop Development Bulletin, Issue no. 15.
• Bradley, C.A. 2008. Fungicides for Soybean: What important foliar diseases need to be controlled Illinois Pest Management and Crop Development Bulletin, Issue no. 17.
• Bradley, C.A. 2008. Foliar fungicides for corn: Just another management tool or the only tool needed pp. 19-21. In: Proceedings of the 2008 University of Illinois Corn and Soybean Classic, Bloomington, Malta, Moline, Springfield, and Whittington, IL.
• Bradley, C.A., Adee, E., Ebelhar, S. and Young, B. 2008. Fungicide control of Fusarium head blight on soft red winter wheat in Illinois. p. 11. In: Proceedings of the 2008 National Fusarium Head Blight Forum, Indianapolis, IN.
• Bradley, C.A., Adee, E., Ebelhar, S., Young, B., Burrows, M., McMullen, M., Lukach, J., Osborne, L., Ruden, K., Sweets, L. and Wise, K. 2008. Multi-state uniform fungicide trials to control Fusarium head blight and deoxynivalenol. pp. 13-16. In: Proceedings of the 2008 National Fusarium Head Blight Forum, Indianapolis, IN.
• Bradley, C.A. and Ames, K.A. 2008. Foliar fungicides in corn production: A look at local and regional data. pp. 81-85. In: Proceedings of the 2008 Illinois Crop Protection Technology Conference, Urbana, IL.
• Bradley, C.A. and McMullen, M.P. 2008. Fungicides for FHB management: Past, present, and future. p. 12. In: Proceedings of the 2008 National Fusarium Head Blight Forum, Indianapolis, IN.
• Bradley, C.A., White, D.G. and Campbell, K.W. 2008. Effect of pyraclostrobin foliar fungicide on multiple corn hybrids. Phytopathology 98:S24.
• Brucker, E.A., Karplus, N.H., Bradley, C.A. and Kolb. F.L. 2008. Evaluation of host plant resistance and fungicide treatment for suppression of Fusarium head blight and deoxynivalenol. p. 150. In: Proceedings of the 2008 National Fusarium Head Blight Forum, Indianapolis, IN.
• Paul, P.A., Bradley, C.A., Robertson, A.E. and Madden, L.V. 2008. Meta-analysis of hybrid corn yield response to foliar fungicides. Phytopathology 98:S123.