Progress 09/01/22 to 08/31/23
Outputs
Target Audience:The target audience during this fourth year of the project has largely been students and postdoctoral associates working on the project studies. We have also increased outreach to the scientific community through abstracts and scientific presentations, to grower, extension, and NRCS communities through outreach activities and presentations, and to undergraduate and graduate students through development of class lecture and lab activities. Changes/Problems:We remain behind on our targeted timeline due to the severe impacts of COVID-19 on research activities during the first and second reporting period, but we expect to complete the project (outside of some manuscript revisions, etc.) by the end of the coming reporting period. What opportunities for training and professional development has the project provided?Multiple undergraduate and graduate students, andpostdoctoral researchers participated in the project during the reporting period, providing numerous opportunities for professional development and training in research methods related to soil disinfestation in organic strawberry systems, and plant defense responses. How have the results been disseminated to communities of interest?During the reporting period multiple activites were conducted to disseminate results to communities of interest. First, multiple scientific presentations(see abstracts in reported publications) were presented to disseminate results to the broader scientific community. Second, one workshopwas conducted to train farmers on soil disinfestation systems at UT Extensions New Farmer's Academy (a training program for early career farmers) at the field research site. Lastly, prototype lab modules were further evaluated with undergraduate and graduate students at the University of Tennessee, who gained exposure to research methods and current understanding of soil disinfestation in organic horticultural systems. What do you plan to do during the next reporting period to accomplish the goals?In the coming reporting period, we plan to complete manuscript preparation as part of Obj. 1, continue manuscript/dissertation preparation as part of Obj. 2, complete RNAseq analysis and a manuscript as part of Obj. 3, and finalize development of educational materials associated with Obj. 4. We expect to continue outreach to the scientific community, grower groups, extension personnel, NRCS personnel, and undergraduate/graduate students through multiple venues.
Impacts
What was accomplished under these goals?
Although we remain behind our anticipated time line due to COVID-19limitations shortly after our project was funded, we are grateful for the no-cost extensions that will allow us to complete this work by the end of the next reporting period. We have completed all studies under Obj. 1 and Obj. 2, and are currently analyzing data and drafting and revising manuscripts. For Obj. 3, RNA seq analysis is in progress. Data from Obj. 1-3 was presented at multiple scientific meetings (and the NIFA-OREI/ORG project director's meeting) during the reporting period (see publications reported). For Obj. 4, we further developed and evaluated lab activity modules and are workingto complete lecture modules and short videos on ASD techniques and will post for public access once completed at the end of reporting period.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
First Report of Strawberry Black Root Rot Caused by Globisporangium sylvaticum in Tennessee, U.S.A. U. Shrestha, M.E. Dee, B.H. Ownley, and D.M. Butler. 2023.
Plant Disease 107:9, 2890. https://doi.org/10.1094/PDIS-01-23-0007-PDN
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Soil Texture, Soil pH, and Amendment Protein: Carbohydrate Ratio Affect Suppression of Fusarium Oxysporum under Anaerobic Soil Conditions By Volatile Fatty Acids and Reduced Metal Cations. 2022. J. Littrell, U. Shrestha, B.H. Ownley and D.M. Butler. 2022 ASA-CSSA-SSSA International Annual Meeting, 6-9 November 2022, Baltimore, MD.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Cover Crop Residue Lignin to Nitrogen Ratio Is an Important Determinant of Strawberry Black Root Rot Pathogen Inoculum Survival When Cover Crops
Are Used As Substrates for ASD Treatment. U. Shrestha, J.J. Littrell, J. Hollis Rice, C. Dalton, B.H. Ownley, and D.M. Butler. 2023. HortScience 58:S162. https://doi.org/10.21273/HORTSCI.58.9S.S1
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Sorghum-Sudangrass As An Organic Amendment In Anaerobic Soil Disinfestation Decreases Disease Severity And Promotes Plant Vigor. W. Ouma, M. Dee, D.M. Butler, U. Shrestha, J.H. Rice, J.J. Littrell, and B.H. Ownley. 2023. 12th International Congress of Plant Pathology, 20-25 Aug 2023, Lyon, France.
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Progress 09/01/21 to 08/31/22
Outputs
Target Audience:The target audience during this third year of the project has largely been students and postdoctoral associates working on the project studies. We have also begun outreach to the scientific community through abstracts and scientific presentations, to grower, extension, and NRCS communities through outreach activities and presentations, and to undergraduate and graduate students through development of class lecture and lab activities. Changes/Problems:We remain behind on our targeted timeline due to the severe impacts of COVID-19 on research activities during the first reporting period. We hope to be able to at least near project completion by the end of thecoming reporting period. What opportunities for training and professional development has the project provided?Multiple undergraduate and graduate students, and a postdoctoral researcher participated in the project during the reporting period, providing numerous opportunities for professional development and training in research methods related to soil disinfestation in organic strawberry systems. How have the results been disseminated to communities of interest?During the reporting period multiple activites were conducted to disseminate results to communities of interest. First, multiple scientific presentations and a workshop (see abstracts in publications) were presented to disseminate results to the broader scientific community. Second, two workshops (a total of fivepresentations) were conducted to train farmers, extension personnel, and NRCS personnel on soil disinfestation systems. This included two presentations to UT Extensions New Farmer's Academy (a training program for early career farmers) at the field research site, two presentations to participants (primarily growers, extension personnel, and students) at the Organic Farming and Gardening Field Day held at the UT Organic Crops Unit (field site for Obj. 2), and one presentation to southern region extension agents on mechanisms of anaerobic soil disinfestation in small fruit production systems as part of the annual training provided by the Southern Region Small Fruits Consoritum. Lastly, prototype lab modules were further evaluated with undergraduate and graduate students at the University of Tennessee, who gained exposure to research methods and current understanding of soil disinfestation in organic horticultural systems. What do you plan to do during the next reporting period to accomplish the goals?In the coming reporting period, we plan to complete manuscript preparation as part of Obj. 1, complete greenhouse/growth chamber studies associated with Obj. 2 and begin manuscript/dissertation preparation, complete the repeated field trial as part of Obj. 2, complete growth chamber and laboratory trials as part of Obj. 3, and finalizedevelopment of educational materials associated with Obj. 4. We expect to continue outreach to the scientific community, grower groups, extension personnel, NRCS personnel, and undergraduate/graduate students through multiple venues.
Impacts
What was accomplished under these goals?
The research limitations imposed by the COVID-19 pandemic greatly eased during this reporting period, although we remain behind our anticipated time line due to those limitations shortly after our project was funded.We have completed all studies underObj. 1 and are preparing a manuscript to submit to a refereedjournal in early 2023. We completed the first set of growth chamber/greenhouse studies under Obj. 2, and will be completing the second set in winter 2023. The first data from Obj. 2 was reported in a presentation at the APS meeting in 2022.The first year of field trials was completed under Obj. 2, and the second year began in late summer/early fall 2022.For Obj. 3, multiple growth chamber trials of strawberryplant defense response to anaerobic soil disinfestation were completed and RNA extraction for RNA seq analysis is in progress. The first data from Obj. 3 was presented at the ASHS meeting in 2022.For Obj. 4, we further developed and evaluated lab activity modules from the last reporting period. We will be completing lecture modules and short videos on ASD techniquesand will post for public access once completedat the end of reporting period.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Shrestha, U., J. Littrell, S. Piya, J.H. Rice, B.H. Ownley, T. Hewezi, D.M. Butler. 2022. Expression Profiling of Pathogenesis-Related Protein-10 (PR10) Genes in Strawberry in Response to Anaerobic Soil Disinfestation. 2022 ASHS Annual Conference, Chicago, Illinois. HortScience S169.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2022
Citation:
W. Ouma, M. Dee, D. Butler, U. Shrestha, H. Rice, J. Littrell, B. Ownley. 2022. Control of Fusarium Root Rot in Strawberries through optimization of Anaerobic Soil Disinfestation with Biostimulants. 2022 American Phytopathology Society Annual Meeting, Plant Health, Pittsburgh, Pennsylvania.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Butler, D.M. 2022. Anaerobic Soil Disinfestation. ASHS Annual Meeting Workshop, Doing More with Less: Reducing Fumigant Use with Alternative Production Systems. HortScience S34.
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Progress 09/01/20 to 08/31/21
Outputs
Target Audience:The target audience during this second year of the project has largely been students and postdoctoral associates working on theproject studies. We have also begun outreach to the scientific community through abstracts and scientific presentations, to grower, extension, and NRCS communities through outreach activities and presentations, and to undergraduate and graduate students through development of class lecture and lab activities. Changes/Problems:The impact of the COVID-19 pandemic and its effects on the ability to conduct timely, on-site work was less of a constraint compared to thefirst year of this project, but still hindered progress. We are closer to our targeted timeline than at the end of the first years reporting period, and will make significant efforts to meet our timeline in the coming reporting period. What opportunities for training and professional development has the project provided?Multiple undergraduate and graduate students, and a postdoctoral researcher participated in the project during the reporting period, providing numerous opportunities for professional development and training in research methods related to soil disinfestation in organic strawberry systems. How have the results been disseminated to communities of interest?During the reporting period multiple activites were conducted to disseminate results to communities of interest. First, multiple scientific presentations (see abstracts in publications) were presented to disseminate results to the broader scientific community. Second, three workshops (a total of five presentations) were conducted to train farmers, extension personnel, and NRCS personnel on soil disinfestation systems. This included two presentations to UT Extensions New Farmer's Academy (a training program for early career farmers) at the field research site, two presentations to NRCS agents in Tennessee as part of their "Working with Organic Farmers" training series, and one presentation to southern region extension agents on soil amendment use in small fruit production systems as part of the annual training provided by the Southern Region Small Fruits Consoritum. Lastly, prototype lab modules were developed and evaluated with undergraduate and graduate students at the University of Tennessee, who gained exposure to research methods and current understandingofsoil disinfestation in organic horticultural systems. What do you plan to do during the next reporting period to accomplish the goals?In the coming reporting period, we plan to complete data analysis and manuscript preparation as part of Obj. 1, complete greenhouse/growth chamber studies associated with Obj. 2, implement the repeated field trial as part of Obj. 2, begin growth chamber and laboratory trials as part of Obj. 3, and complete development of educational materials associated with Obj. 4. We expect to continue outreach to the scientific community, grower groups, extension personnel, NRCS personnel, and undergraduate/graduate students through multiple venues.
Impacts
What was accomplished under these goals?
TheCOVID-19 pandemic and its effects on the ability to conduct timely, on-site work remained a constraint into the second year of this project. However, we have largely completed data collection for Obj. 1, implemented field and growth chamber/greenhouse studies under Obj. 2, and developed and tested course laboratory activities under Obj. 4. In Obj. 1, we evaluated wheat cover crop residue as an ASD amendment with varying lignin to N ratio (L:N) on survival of an inoculated isolate of Fusarium oxysporum (Fo) causing root rot of strawberry and indigenous soil fungi following soil treatment by ASD. Treatments included 1) vegetative stage wheat residue,1:1 L:N, 2) reproductive stage wheat residue, 2:1 L:N, and 3) mature wheat residue, 7:1 L:N, 4) a wheat bran control, and 5) a non-amended anaerobic control. The ASD experiment was conducted in pots with sandy soil in a growth chamber at 25-35°C, and repeated. All treated pots showed high anaerobic condition except for the mature wheat stage and the anaerobic control. Wheat residue with low L:N (1:1 and 2:1) substantially reduced recovered Fo inoculum populations compared to other treatments, with no negative impact on indigenous Trichoderma spp. or Aspergillus spp. Our results suggest that low L:N of wheat cover crop residue is needed to suppress the pathogenic Fo during ASD. We expect to complete data analysis and submit a manuscript for review in the next reporting period. In Obj. 2., greenhouse/growth chamber and field (high tunnel) studies were established at the end of the reporting period (late summer/early fall 2021). For Obj. 4, we developed two lab activity modules, evaluated with students, and will be editing based on student and instructor feedback in the next reporting period.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
Shrestha, U., B. H. Ownley, J. H. Rice, R. J. Vichich, and D. M. Butler*. 2020. Susceptibility of Rhizoctonia solani and Fusarium oxysporum to volatile fatty acids. Proceedings of the Annual International Research Conference on Methyl Bromide Alternatives, 8-1 to 8-3.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Shrestha, U., J. Hollis Rice, J. Littrell, B.H. Ownley, D.M. Butler*. 2021. ASD amendment lignin to nitrogen ratio affects mortality of Fusarium oxysporum inoculum. American Phytopathology Society Annual Meeting, Plant Health 2021 (online).
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Shrestha, U.*, B.H. Ownley, D.M. Butler. 2021. Anaerobic/Biological Soil Disinfestation: Effects on Survival of Soilborne Pathogens and Beneficial Organisms. ASHS Annual Meeting Workshop, Strategies and Challenges for Implementing Anaerobic Soil Disinfestation. HortScience 56(9),S150.
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Progress 09/01/19 to 08/31/20
Outputs
Target Audience:The target audience during this first year of the project has largely been students and postdoctoral associates working on the initial project studies. Changes/Problems:The impact of the COVID-19 pandemic and its effects on the ability to conduct timely, on-site work were a major constraint to the first year of this project given that most proposed work at this stage could not be conducted remotely. We were able to make substantial progress on Obj. 1, and hope that we will be able to be closer to our targeted time line in the coming year. What opportunities for training and professional development has the project provided?Multiple undergraduate and graduate students, and a postdoctoral researcher participated in the project during the reporting period, providing numerous opportunities for professional development and training in research methods related to soil disinfestation in organic strawberry systems. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?In the coming reporting period, we plan to complete pot studies in Obj. 1 with an additional pathogen (Pythium spp.), and begin pot and field studies associated with Obj. 2. We expect that we will present our first results at scientific meetings (American Phytopathological Society), begin Obj. 3 lab work, and begin development of educational materials associated with Obj. 4.
Impacts
What was accomplished under these goals?
The impact of the COVID-19 pandemic and its effects on the ability to conduct timely, on-site work were a major constraint to the first year of this project given that most proposed work at this stage could not be conducted remotely. We were able to make substantial progress on Obj. 1, and hope that we will be able to be closer to our targeted time line in the coming year. For Obj. 1,wheat cover crop residue lignin to N ratio at three stages was evaluated for optimizinganaerobic soil disinfestation (ASD) to reduce survival of Fusarium oxysporum (Fo). Fo isolates were collected strawberry inTennessee. Inoculum was produced using presoaked organic oats autoclaved twice at 121°C for 15 min. TheFo isolate was grown on PDA andmycelial plugs (5-10mm) were transferred to autoclaved oats and incubated under fluorescent light for 15 days at room temperature. After gaining full colonization of oats, the Fo inoculum was driedfor 24 hour and stored at 4°C. Packets with 2 g of inoculum were prepared using nylon bags for growth chamber pot studies. The growth chamber study used potsfilled with 1.4 kg soil mixture (soil:sand=1:1) and wheat amendments at 3 lignin:N ratios. Temperatures were 25°C for 10 hour and 35°Cfor 14 hourto simulate a soil temperature regime in the southeastern U.S. during the time of a summer ASD treatment prior to fall strawberry planting. The treatmentamendments included ground wheat residues at three wheat growth stageswith a range of lignin:N ratios (wheat vegetative stage,1:1 lignin:N ratio, reproductive stage, 2:1 ratio, andharvest stage, 7:1 ratio. A positive control with wheat bran as the carbon source was included. The total carbon rate for each treatment was maintained at 4 mg C / of soil. An anaerobic, non-amended & irrigated control and an aerobic, non-amended & irrigated control were also included. The Fo inoculum was introduced at3-5 cm depth, iron oxyhydroxide coated (IRIS) tubes and manganese oxide (MnO) painted stakes were installed at 10 cm depth following amendment incorporation to assess soil anaerobic conditions. Pots were irrigated to saturation, covered with black polyethylene mulch,and incubated in the growth chamber. Pots were arranged in a completely randomized design. Following ASD treatment, IRIS tubes, MnO stakes were removed and percentage of Fe or Mn paint removal by soil reduction was assessed. Fo packets were removed and propagule survival were assessed by serial dilution plating of recovered inoculum onto Nash-Snyder selective media. Soil samples were collected and extractedto evaluate soil concentrations of volatile fatty acids (VFAs). Preliminary results showed high anaerobic condition generated in the wheat treatments with low lignin to N ratios (1 and 2:1), that was comparable with wheat bran treatment (41 to 57% Mn; 35 to 45% Fe paint removal). The high lignin to N ratio (7:1; ~20% paint removal) indicated low anaerobic conditions and was not different from anaerobic control (0% Mn;13% Fe paint removal). Mortality ofFoinoculumwas highestin the low wheat lignin:N ratio (1:1) amended pots compared to all other treatments. When compared to the anaerobiccontrol, wheat at low lignin:N reducedFopopulationby 98%.
Publications
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