Progress 05/01/08 to 09/30/10
Outputs
OUTPUTS: The investigators have met bi-weekly to discuss progress and milestones in relation to the project timetable in the original proposal. All planned field experiments have been completed and evaluated according to schedule, and a 2009 experiment was repeated in 2010. Greenhouse experiments also have been completed. Data analyses and summary of the results also have been completed according to schedule, with a few exceptions, particularly related to DNA-based method development for identifying Fusarium isolates from survey samples. Results of this project on soybean Fusarium root rot have been presented and discussed with stakeholder groups on several occasions, including the Iowa Soybean Association, through the Iowa Corn and Soybean Initiative, and at ISU Extension programs held at the ISU Field Extension Education Laboratory. Because seed treatment utilization is an important component of the project, we also discussed the project at Seed Treatment workshops at the ISU Seed Science Center in 2008, 2009, and 2010 and at the 2009 and 2010 Soybean Seed workshops at the Seed Science Center. Information from the project informed two articles in Integrated Crop Management News by ISU Extension in 2009. Results of the project were presented at the 2010 Integrated Crop Management Conference in December 2010, with an accompanying proceedings article that includes more detailed results. To communicate the results to the research community, poster presentations were made at the 2008, 2009, and 2010 Annual Meetings of the American Phytopathological Society. We also anticipate two peer-reviewed journal papers that will be prepared in 2011. We conducted brainstorming sessions in the spring of 2008 with other soybean Fusarium researchers in Iowa, Minnesota, and North Dakota in order to share methods and coordinate activities. PARTICIPANTS: The project is being led by Drs. Munkvold and Leandro with substantial contributions from Dr. Tylka and Dr. Fessehaie. Drs. Munkvold and Leandro are co-advising a graduate student (Ms. Mercedes Diaz) assigned to the project. Dr Alison Robertson coordinated the root sample collection in 2008. ISU Extension Field Specialists are cooperating in the collection of root samples. This project involves two units of the ISU College of Agriculture and Life Sciences: The Department of Plant Pathology (Chair: Dr. Thomas Baum) and the Seed Science Center (Director: Dr. Manjit Misra). Personnel from the ISU research and Demonstration Farms (supervised by Mr. Michael Fiscus) are assisting with field preparation and operations. Iowa Soybean Association and the ISU Corn and Soybean Initiative are an important partners in the research. Training opportunities associated with this project have included ISU Seed Science Center workshops and ISU Extension workshops. TARGET AUDIENCES: Target audiences for this project include soybean producers and other individuals associated with soybean production in any capacity,including seed company and crop protection chemical company agronomists, pathologists, and breeders; crop consultants, field extension personnel, and other soybean researchers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The primary outcomes from this research project on Fusarium root rot of soybean have been changes in knowledge that can be gained from the experimental data. Twelve different Fusarium species have been recovered from soybean roots. Fusarium oxysporum has been the most frequently occurring Fusarium species in soybean roots in Iowa so far, followed by F. acuminatum, F. solani, and F. graminearum. Plants sampled during vegetative growth stages yielded a greater diversity of Fusarium species than did plants sampled during reproductive growth stages. Within each species, there is a range of aggressiveness to soybean roots, but F. graminearum isolates appear to be consistently the most aggressive. The greatest variability occurred within F. oxysporum; some isolates were highly aggressive, causing severe root rot and reductions in shoot and root growth in greenhouse experiments. Other isolates did not cause root rot or reduce plant growth. Soybean yields in field microplots were affected by Fusarium inoculation, but root rot was not severe and yield impacts were inconsistent. For some isolates, there was a significant linear relationship between root rot severity and yield, whereas other isolates caused root rot symptoms without affecting yield. In a location with Iron deficiency chlorosis (IDC) symptoms, there were differences in symptom severity between soybean varieties, and a seed treatment including fungicides, insecticide, and a biological active ingredient alleviated IDC symptoms in one variety in 2009 and 2010. Soybean cyst nematode (SCN) infestation increased the severity of root rot caused by some isolates of Fusarium in greenhouse experiments, but had no measurable interaction with other isolates. In field locations infested with SCN, there was no relationship between SCN resistance and Fusarium root rot symptoms among soybean varieties, although there was a relationship between SCN infestation and root rot severity. There also was a significant positive correlation between soil pH and root rot severity. We anticipate that the project's results will have an impact on soybean management practices in relation to the use of Soybean Cyst Nematode resistant varieties, the use of seed treatments in soybeans, and production practices in high-pH soils.
Publications
- Diaz-Arias, M.M., Leandro, L., and Munkvold, G.P. 2008 (Poster abstract). Frequency of Fusarium species associated with soybean roots in Iowa. Phytopathology 98:S46
- Diaz-Arias, M.M., Munkvold, G.P., and Leandro, L.L. 2009 (Poster abstract). Impacts of Fusarium root inoculation on soybean plants. Phytopathology 99:S29
- Diaz-Arias, M. M., Tylka, G., Leandro, L., and Munkvold, G. 2010 (Poster abstract). Effects of soybean cyst nematode infestation and resistance on Fusarium root rot on soybeans. Phytopathology 100:S30.
- Diaz-Arias, M.M., Tylka, G.L., Robertson, A., Leandro, L., and Munkvold, G.P. 2010. Fusarium root rot of soybean: occurrence, impact, and relationship with soybean cyst nematode. Pp. 115-123 in Proc. 22nd Annual Integrated Crop Management Conf., Ames, IA, Dec 1-2, 2010.
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Progress 05/01/09 to 04/30/10
Outputs
OUTPUTS: The investigators meet bi-weekly to discuss progress and milestones in relation to the project timetable in the original proposal. All planned field experiments have been established and evaluated according to schedule, but we are repeating a 2009 experiment in 2010. Most greenhouse experiments have been completed, but these are behind schedule due to malfunctions of the temperature-control system in the greenhouse. Data analyses and summary of the 2008 and 2009 results also have been completed according to schedule, with a few exceptions, particularly related to DNA-based method development for identifying Fusarium isolates from survey samples. Results of this project on soybean Fusarium root rot have been presented and discussed with stakeholder groups on several occasions, including the Iowa Soybean Association, through the Iowa Corn and Soybean Initiative, and at ISU Extension programs held at the ISU Field Extension Education Laboratory. Because seed treatment utilization is an important component of the project, we also discussed the project at Seed Treatment workshops at the ISU Seed Science Center in 2008, 2009, and 2010 and at the 2009 and 2010 Soybean Seed workshops at the Seed Science Center. Information from the project informed two articles in Integrated Crop Management News by ISU Extension in 2009. Results of the project will be presented at the 2010 Integrated Crop Management Conference in December 2010, with an accompanying proceedings article that includes more detailed results. To communicate the results to the research community, poster presentations were made at the 2008, 2009, and 2010 Annual Meetings of the American Phytopathological Society. We also anticipate two peer-reviewed journal papers that will be prepared in 2011. We conducted brainstorming sessions in the spring of 2008 with other soybean Fusarium researchers in Iowa, Minnesota, and North Dakota in order to share methods and coordinate activities. PARTICIPANTS: The project is being led by Drs. Munkvold and Leandro with substantial contributions from Dr. Tylka and Dr. Fessehaie. Drs. Munkvold and Leandro are co-advising a graduate student (Ms. Mercedes Diaz) assigned to the project. Dr. Alison Robertson coordinated the root sample collection in 2008. ISU Extension Field Specialists are cooperating in the colleciton of root samples. This project involves two units of the ISU College of Agriculture and Life Sciences: The Department of Plant Pathology (Chair: Dr. Thomas Baum) and the Seed Science Center (Director: Dr. Manjit Misra). Personnel from the ISU Research and Demonstration Farms (supervised by Mr. Michael Fiscus) are assisting with field preparation and operations. Iowa Soybean Association and the ISU Corn and Soybean Initiative are an important partners in the research. Training opportunities associated with this project have included ISU Seed Science Center workshops and ISU Extension workshops. TARGET AUDIENCES: Target audiences for this project include soybean producers and other individuals associated with soybean production in any capacity, including seed company and crop protection chemical company agronomists, pathologists, and breeders; crop consultants, field extension personnel, and other soybean researchers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The primary outcomes from this research project on Fusarium root rot of soybean have been changes in knowledge that can be gained from the experimental data. This information continues to be developed is and still subject to verification. At least ten different Fusarium species have been recovered from soybean roots. Fusarium oxysporum has been the most frequently occurring Fusarium species in soybean roots in Iowa so far, followed by F. solani, F. acuminatum, and F. graminearum. Within each species, there is a range of aggressiveness to soybean roots, but F. graminearum isolates appear to be consistently the most aggressive. The greatest variability occurred within F. oxysporum; some isolates were highly aggressive, whereas others did not cause root rot in greenhouse experiments. Soybean yields in field microplots were affected by Fusarium inoculation, but significant yield reductions occurred for only a few isolates in 2008 and 2009. In a location with Iron deficiency chlorosis (IDC) symptoms, there were differences in symptom severity between soybean varieties, but a seed treatment including fungicides, insecticide, and a biological active ingredient did not alleviate IDC symptoms in either variety in 2008 or 2009. In field locations infested with soybean cyst nematode (SCN), there was no relationship between SCN resistance and Fusarium root rot symptoms among soybean varieties, although there was a relationship between SCN infestation and root rot severity. There also was a significant positive correlation between soil pH and root rot severity. We anticipate that the project's results will have an impact on soybean management practices in relation to the use of Soybean Cyst Nematode-resistant varieties, the use of seed treatments in soybeans, and production practices in high-pH soils.
Publications
- Diaz-Arias, M.M., Munkvold, G.P., and Leandro, L.L. 2009. Impacts of Fusarium root inoculation on soybean plants. Phytopathology 99:S29.
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Progress 05/01/08 to 04/30/09
Outputs
OUTPUTS: The investigators meet bi-weekly to discuss progress and milestones in relation to the project timetable in the original proposal. During 2008 and the first two quarters of 2009, all field and experiments have been established and evaluated according to schedule. Greenhouse experiments are underway and some have been completed, but these are behind schedule due to malfunctions of the temperature-control system in the greenhouse. Data analyses and summary of the 2008 results also have been completed according to schedule, with a few exceptions, particularly related to DNA-based method development for identifying Fusarium isolates from survey samples. From a communication standpoint, we had originally anticipated sharing preliminary results in the Integrated Crop Management News and Conference in late 2008, but we decided that the results were not sufficiently well-developed and it would have been premature to engage in those communication efforts at that time. Most of the expected outputs from this research project on Fusarium root rot of soybean are still under development. The project has been presented and discussed with stakeholder groups on several occasions, including the Iowa Soybean Association in July 2008, through the Iowa Corn and Soybean Initiative, and at ISU Extension programs held at the ISU Field Extension Education Laboratory. Because seed treatment utilization is an important component of the project, we also discussed the project at Seed Treatment workshops at the ISU Seed Science Center in June 2008 and June 2009, and it will also be discussed at the July 2009 Soybean Seed workshop at the Seed Science Center. The project background goals, and progress were presented to other researchers in the ISU Dept. of Plant Pathology in 2008. We are preparing a brief article for the ISU Integrated Crop Management News, timed for late summer 2009 when soybean producers may be noticing symptoms of Fusarium root rot. Results of the project should be sufficiently defined in time for presentation at the 2009 Integrated Crop Management Conference in Dec 2009, with an accompanying proceedings article that includes more detailed results. To communicate the results to the research community, a poster presentation was made at the 2008 Annual Meeting of the American Phytopathological Society, and another poster will be presented at that meeting in 2009. We also anticipate two peer-reviewed journal papers that will be prepared in 2010. We conducted brainstorming sessions in the spring of 2008 with other soybean Fusarium researchers in Iowa, Minnesota, and North Dakota in order to share methods and coordinate activities. PARTICIPANTS: The project is being led by Dr. Munkvold and Dr. Leandro with substantial contributions from Dr. Tylka and Dr. Fessehaie. Drs. Munkvold and Leandro are co-advising a graduate student (Ms. Mercedes Diaz) assigned to the project. Dr. Alison Robertson coordinated the root sample collection in 2008. ISU Extension Field Specialists are cooperating in the collection of soybean root samples. This project involves two units of the ISU College of Agriculture and Life Sciences: the Dept. of Plant Pathology (Chair: Dr. Thomas Baum) and the Seed Science Center (Director: Dr. Manjit Misra). Personnel from the ISU Research and Demonstration Farms (supervised by Mr. Mike Fiscus) will assist with field preparation and operations. Iowa Soybean Association is an important partner in the research. Training opportunities associated with this project have included ISU Seed Science Center workshops where the project background and goals have been discussed. TARGET AUDIENCES: Target audiences for this project include soybean producers and other individuals associated with soybean production in any capacity, including seed company and crop protection company agronomists, pathologists, and breeders, crop consultants, field extension personnel, and other soybean researchers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The primary outcomes from this research project on Fusarium root rot of soybean have been changes in knowledge that can be gained from the experimental data. This information is preliminary and still subject to verification. At least ten different Fusarium species were recovered from soybean roots. Fusarium oxysporum has been the most frequently occurring Fusarium species in soybean roots in Iowa so far, followed by F. solani, F. acuminatum, and F. graminearum. Within each species, there is a range of aggressiveness to soybean roots, and no one species was consistently the most aggressive. The greatest variability occurred within F. oxysporum; some isolates were highly aggressive, whereas others did not cause root rot in greenhouse experiments. Soybean yields in field microplots were affected by Fusarium inoculation, but significant yield reductions occurred for only a few isolates in 2008. Yield and root rot data from fumigated plots did not indicate significant differences among treatments. In a location with Iron deficiency chlorosis (IDC) symptoms, there were differences in symptom severity between soybean varieties, but a seed treatment including fungicides, insecticide, and a biological active ingredient did not alleviate IDC symptoms in either variety. In field locations infested with soybean cyst nematode (SCN), there was no relationship between SCN resistance and Fusarium root rot symptoms among soybean varieties. We anticipate that the project's results will have an impact on soybean management practices in relation to the use of Soybean Cyst Nematode-resistant varieties, the use of seed treatments in soybeans, and production practices in high-pH soils, but these impacts will depend primarily on communication efforts conducted in late 2009 and 2010.
Publications
- Diaz-Arias, M.M., Leandro, L., and Munkvold, G.P. 2008. Frequency of Fusarium species associated with soybean roots in Iowa. Phytopathology 98:S46
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