Progress 09/01/20 to 08/31/21
Outputs Target Audience:The target audiences reached by our efforts during thisreporting period were farmers, breeders, germplasm curators, extension specialists and agents, university collaborators, USDA collaborators, and our advisory board. Changes/Problems:Progress in some objectives has been delayed due to coronavirus-related restrictions but we are making good progress towards objective completion, and we do not expect any issues in performing project activities as proposed. Survey efforts, training programs and grower awareness meetings have been curtailed by travel and meeting restrictions. What opportunities for training and professional development has the project provided?Multiple Extension meetings, Field Days, and workshops throughput North Carolina, South Carolina, Georgia, and Florida. NCSU: Faculty, technicians, postdocs, graduate students, and undergraduate students have received training in nematode biology and management through this project. Some personnel in our groups that are not directly supported by the project have also benefited and learned from the activities performed in our programs. Early-career scientists from underrepresented backgrounds have been effectively engaged in the project. USDA-ARS: A post-doc (Dr. Benjamin Waldo) was hired to perform the M. e. screening experiments at the USVL and had the opportunity to begin screening watermelon and sweetpotato. A master's student (Julianna Culbreath) helped to set up the screening experiments for both pepper and sweetpotato, and is working to develop the new storage root survey method for M.e. Clemson: One-on-one training sessions were held with Zack Snipes (Charleston area Hort. agent), Justin Ballew (Lexington Commercial Hort. Agent), Rob Last (Savannah Valley Hort. agent), and Phillip Carnley (Orangeburg Area Commercial Hort. Agent). Did one-on-one in-field trainings with Agronomic row crop agents Jonathan Croft (Orangeburg & Dorchester Counties), Jay Crouch (Newberry & Saluda Counties), Steven Crowder (Allendale & Hampton Counties), and Hannah Mikel (Clarendon & Sumter Counties), One-on-one training sessions in-the-field were held with Crop Consultants Jerry Adams (Lee County area) and Fleming McMaster (Upper Savannah Valley area). UF: The bioscientist on this project learned to identify root-knot nematode species using PCR-based molecular techniques. Gaining experience with molecular techniques is something they identified as an important part of their professional training. Student training and postdoc professional development was also provided. New MS student was trained in molecular id of M.e. UGA: A MSc student (Gema Nugraha) and a Postdoc (Banani Mondal) were hired to work on molecular detection of root-knot nematodes. How have the results been disseminated to communities of interest?Scientific Meetings, Extension publications, Extension meetings and events, Web-based materials. NCSU: We have presented results from this project to stakeholders at several extension venues such as the annual North Carolina Sweetpotato field day, the Organic Commodities and Livestock Conference, field days, and regional crop production meetings. We have also presented at scientific conferences such as the Annual Southern Division American Phytopathological Society Meeting, the American Phytopathological Society Annual Meeting, and the Society of Nematologists Annual Meeting. Clemson: Survey results and the damage potential of M.e. were presented to growers, agents, and industry personnel at the S.C. State Cotton meeting (125+ attendees), the Savannah Valley Cotton Production Meeting (75 attendees), Edisto REC Fall Field Day (50 attendees), the 2019 Certified Crop Advisors training meeting (30 attendees) and to meetings of the S.C. Cotton and Soybean Boards (25 attendees). We have also presented at scientific conferences such as the National Sweetpotato Collaborators Group Annual Meeting and the Annual Southern Division American Phytopathological Society Meeting. UF: Results have been distributed through direct contact with growers and Extension Agents, publication of trade articles and Extension documents (in progress), presentations at regular extension events, and social media updates. Results were presented at Society of Nematology 2021 meeting in Alabama by Hung Bui (postdoc, Asian vegetables)), David Moreira (grad student, nematicide effects) and Gabrieli Riva (grad student, M.e. survey results). Updates on M.e. work was also given at grower's meetings (FL Ag expo, Strawberry grower's meeting, tomato grower's meeting and several county extension meetings). UGA: Outreach activities were done at multiple county grower meetings and Extension agent workshops in Georgia as well as at the Southeast Regional Fruit and Vegetable Conference (Savannah, GA) on the importance of M. enterolobii as a potential threat to agricultural crops. USDA-ARS: We disseminated information on the threat posed by M.e. and project results through two seminars presented to the departments of Plant Pathology at Louisiana State University and the University of Georgia, as well as through a virtual sweetpotato stakeholder symposium which had over 125 attendees. Examples: Production Guides 1. Southeastern Vegetable Extension Workers. Kemble J., Meadows I., Jennings K. M., and Walgenbach J. F., Eds. (2022) Southeastern US 2022 Vegetable Crop Handbook. Basil, cucurbits, hop, lettuce, endive, sweetpotato, and fungicide resistance tables (Quesada Contributed 11 tables total). 2. Quesada-Ocampo L. M., Meadows I., and Gorny A. (2022) Disease control for commercial vegetables. North Carolina Agricultural and Chemicals Manual. Basil, cucurbits, hop, lettuce, endive, sweetpotato, and fungicide resistance tables (Quesada Contributed 11 tables total). 3. Southeastern Vegetable Extension Workers. Kemble J., Meadows I., Jennings K. M., and Walgenbach J. F., Eds. (2021) Southeastern US 2021 Vegetable Crop Handbook. Basil, cucurbits, hop, lettuce, endive, sweetpotato, and fungicide resistance tables (Quesada Contributed 11 tables total). Extension Fact Sheets 1. Quesada-Ocampo L. M. (2017, updated in 2020 and 2021) Sweetpotato root knot nematode. Vegetable Pathology Factsheets. NC State Extension Publications. URL: https://content.ces.ncsu.edu/sweetpotato-root-knot-nematode 2. Schwarz, T. and Gorny, A. 2020. Root-Knot Nematode of Tomato. NC State Extension Publication. URL: https://content.ces.ncsu.edu/root-knot-nematode-of-tomato 3. Agudelo, P. and Day, J. 2020. Factsheets for management of M. enterolobiii, for commercial growers and for homeowners.The latest nematode invasion in the southeast US -- FINDMe (findmenematode.org) Extension websites for stakeholder training 1. Extension Plant Pathology Portal: http://plantpathology.ces.ncsu.edu/. 2. Vegetable Pathology lab website: http://go.ncsu.edu/veggiepathology/. 3. Grabau Z. J. and Liu C. (2020) What Florida growers need to know about the invasive guava root-knot nematode. Panhandle Ag e-News. URL: https://nwdistrict.ifas.ufl.edu/phag/2020/10/30/what-florida-growers-need-to-know-about-the-invasive-guava-root-knot-nematode/ What do you plan to do during the next reporting period to accomplish the goals?We will continue sampling efforts and will intensify greenhouse and field evaluations. We will analyze datafrom previously completed experiments and will continue to refine the economic models. New educational materials will be produced. NCSU: Quesada will generate publications to report findings of vegetable crops at risk of M. enterolobii infection and weeds that could serve as a green bridge for this nematode. Gorny will generate publications and extension deliverables of host resistance in sweetpotato to M. enterolobii. Quesada and Gorny will also continue field experiments to evaluate chemical control options for management of M. enterolobii. Quesada and Gorny will continue efforts to disseminate findings of this project to stakeholders. USDA-ARS: USDA-ARS: We will begin screening a core set of 384 genetically diverse sweetpotato clones for resistance to M.e. We will test additional advanced sweetpotato clones for resistance to M.e. We will confirm any M.e. resistance identified in the ongoing wild watermelon screens. We will begin developing biparental populations by crossing the M.e. tolerant pepper line, PMER-2, to susceptible pepper lines. Additional sweetpotato storage root samples will be collected and screened using our new survey method. Clemson:Continue to solicit samples from Horticulture and Agronomic agents throughout the Midlands and the Coastal Plain of SC will be solicited in person to submit nematode samples from cotton, soybean, sweetpotato and vegetable fields with a history of root-knot nematode problems. When possible, Dr. Mueller will personally visit the fields to collect samples and give one-on-one training to growers and consultants involved with the fields. If samples contain root-knot nematodes, females will be collected and speciated. If COVID 19 restrictions on travel and indoor group meetings are relaxed, Dr. Mueller will give presentations at county and regional crop production meetings that include information on distribution and management of M. enterolobii. Otherwise, he will work to increase the number of within state Zoom meetings he participates in.
Impacts What was accomplished under these goals?
IMPACT.We have increased our knowledge of incidence, distribution, and genetic variability of the invasive M.e. in the southeastern US.We identified sources of resistance for germplasm development. Promising materials will be made available for breeders to incorporate into elite varieties.We evaluated non-host rotation options and other management tactics including the use of nematicides. NCSU and UF assessed the efficacy of nematicides, cover crops, and rotational crops. Findings will be critical to improve integrated pest management strategies. Objective 1. CU: We collectedsamples for 93 vegetable and 67 row crops. Many did not testas M. incognita;none of them wereM. enterolobii. These samples came from Bamberg, Barnwell, Charleston, Clarendon, Colleton, Hampton, Lexington, Newberry, Saluda, and Sumter counties. USDA: We developed a method for testing batches of sweetpotato. Fifteen batches were tested using our new survey methodology, including 8 samples collected from grocery stores and grower fields in South Carolina. We have detected and/or recovered live root-knot nematodes from 5 of these sweetpotato samples, and are in the process of confirming our species identification. UF: Total of 223 root or soil samples were collectedfrom commercial agronomic and row crops in North Florida. Of samples collected, Meloidogyne spp. were detected in 100 samples. Molecular identification revealed M. incognita (15), M. arenaria (8), M. javanica (1), and M. enterolobii (9). UGA: 187 soil samples were received fromcotton, peanut, tobacco, and several vegetable crops in 35 counties. Most fields were infested with only Meloidogyne incognita (82%) followed by a mixed population of M. incognita and M. arenaria (9%); M. arenaria (5%); M. javanica (1%); M. incognita and M. javanica (1%); M. arenaria and M. javanica (1%), and a mixed population of the three species (1%). Objective 2. NCSU: Quesada evaluated the susceptibility of 18 hosts to a North Carolina population ofM. enterolobii.Trials were performed in the greenhouse to determine the level of galling and the eggs per gram of fresh root (ER) after 45 days. Hosts evaluated included cucumber 'Arabian', watermelon 'Fascination' and 'Charleston gray', cabbage 'Stonehead', pepper 'Red Bull', hemp 'Felina', peanut 'Sulivan' and 'Tifguard', corn 'Early sunglow', tobacco 'K326', cotton 'Deltapine 1646', soybean '7310RY' and 'P5018RX', winter wheat 'Kaskia', sudangrass 'Piper', and the weeds palmer amaranth, yellow nutsedge, and broadleaf signalgrass. Two watermelon varieties, cabbage, pepper, one soybean variety, and tobacco were significantly infected withM. enterolobii. Broadleaf signalgrass, corn, one peanut variety, sudangrass, and nutsedge were less susceptible toM. enterolobiiand considered poor hosts. Gorny began evaluating the durability of resistance in sweetpotato by screening diverse sweetpotato genotypes against two distinct populations ofM. enterolobiifrom North Carolina. In the greenhouse, replicate trials are ongoing to determine the severity of root galling and eggs per gram of fresh root for nine sweetpotato genotypes ('Beauregard', 'Covington', 'Centennial', 'Jewel', 'Murasaki-29', 'Tanzania', 'Dimbuka-Bukulula', 'Bwanjule', and Tib-11 [genotype from an experimental cross]). Of these, 'Murasaki-29', 'Tanzania', 'Dimbuka-Bukulula', 'Bwanjule', and Tib-11, were determined to be resistant in prior experiments, but durability of the resistance was unknown. USDA-ARS:Sixty-nine first year seedlings were selected from breeding nurseries that had M.e. resistant parents. Two advanced breeding sweetpotato clones were confirmed to be resistant to M.e. and intermediately resistant to other soil dwelling pests. The newly identified clones will be used in sweetpotato breeding nurseries in FY22. An M.e. tolerant pepper line was selected, PMER-2, which displayed less galling and nematode egg production compared to susceptible control lines and produced a 70% larger root system under infected conditions. Crosses have been initiated in the greenhouse to determine if this resistance trait will be useful for breeding new resistant pepper varieties. Screens are underway to evaluate the susceptibility of 126 diverse wild watermelon lines to M.e. Objective 3. NCSU: One trial was conducted in 2020 to evaluate chemical and host resistance control options for M. enterolobii in sweetpotato. The site had variable nematode counts with the non-treated control showing very low nematode pressure. Two trials were established in 2021 to evaluate chemical control options for M. enterolobii in sweetpotato. Both sites were confirmed to be infested with the nematode. UF: We analyzed the 2019 and 2020 tomatoes' yield data provided by UF GCREC Dr. Desaeger's team to evaluate the economic feasibilities of different nematode treatments. Preliminary results show that the most widely adopted treatment, fumigation, may not be the most economically profitable option for the Florida tomato growers. Efficacy of four chemical nematicides (oxamyl, fluensulfone, fluopyram, fluazaindolizine) and six biological nematicides) was evaluated in vitro (on M.e. juveniles) and in the greenhouse on cucumber inoculated with M.e. eggs. All chemical nematicides reduced M.e. activity in vitro and M. e. infection on cucumber in the greenhouse. Biological nematicides showed no or minor effects. Velum, Vydate and Melocon are also being evaluated in a commercial pepper and Asian vegetable field naturally infested with M.e. Four common cover crops (sunn hemp, cowpea, sorghum-sudangrass and sunflower) were evaluated in the greenhouse for their host potential towards four root-knot species. M.e. did not reproduce on Sunn hemp and sorghum sudan, but reproduced well on sunflower and cowpea. Objective 4. UF: The US sweetpotato industry supply and price data model was used to quantify the US sweetpotato price responses to the supply shocks. The analysis shows the US sweet potato prices are highly sensitive to supply quantity and further highlight the importance and dominance of North Carolina sweet potatoes to the US market. The result suggests preventing supply disruptions like an outbreak of M.e. in North Carolina will affect not only the production and market supply of sweetpotatoes but also the market prices. ?Objective 5. USDA: Dr. Rutter and Dr. Wadlproduced a videodescribing the threat posed by M.e. and the research our group is working on to manage and mitigate the spread of this nematode in the field. NCSU:Quesada provided diagnostics and disease management recommendations for 97 vegetable crop samples submitted in 2020 to the NC State Plant Disease and Insect Clinic. Gorny has been involved with providing nematode biology and management information through direct recommendations to growers and agents, and oral presentations. Quesada and Gorny have generated disease management publications such as the NC Agricultural and Chemicals Manual and the Southeastern US Vegetable Crop Handbook. Gorny has created three extension videos from project initiation to date onM. enterolobiiin sweetpotato. Clemson: We increased project awareness through popular press and new materials on website (https://www.findmenematode.org/) and social media (https://twitter.com/FINDMeNematode). The team developed blogs and factsheetsforhomeownersand commercial growers to increase awareness ofM.e. The factsheetswere translated into Vietnamese and Spanish. All investigators have presented results as oral talks or posters at scientific conferences such as the Annual Southern Division American Phytopathological Society Meeting, American Phytopathological Society Annual Meeting, and the Society of Nematologists Annual Meeting.
Publications
- Type:
Book Chapters
Status:
Published
Year Published:
2021
Citation:
Parada-Rojas C. H., Quesada-Ocampo L. M. (2021) Uncovering the NLR family of disease resistance genes in cultivated sweetpotato and wild relatives. Chapter 3. In: Postharvest Pathology: Next Generation Solutions to Reducing Losses and Enhancing Safety. Editors: Spadaro D., Droby S., and Gullino M.L. Springer.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
Rutter, W. B., Wadl, P. A., Mueller, J. D. and P. Agudelo. 2020. Identification of Sweetpotato Germplasm Resistant to Pathotypically Distinct Isolates of Meloidogyne enterolobii from the Carolinas. Plant Disease (in press)
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2021
Citation:
Parada-Rojas C. H. and Quesada-Ocampo L. M. Revealing the NLRome of cultivated hexaploid sweetpotato. Phytopathology: in press.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Wong T. S. and Quesada-Ocampo L. M. (2020) Evaluation of SDHIs for control of southern root-knot nematode and fungal pathogens in watermelon. Phytopathology 110: S1.20.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
Ye W, Schwarz T., Davis E. L., Thiessen L. D., Quesada-Ocampo, L. M., and Gorny A. M. (2020) Occurence of the root-knot nematode Meloidogyne enterolobii infecting sweetpotato in North Carolina, United States. Phytopathology 110: S1.2.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Philbrick, A., Adhikari, T. B., Louws, F. J., and Gorny, A. M. 2020 . Meloidogyne enterolobii, a major threat to tomato production: Current status and future prospects for its management. Frontiers in Plant Science. 11:article 606395 DOI:10.3389/fpls.2020.606395
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2021
Citation:
Collins H., Adams M. L., Quesada-Ocampo L.M. (2021) Evaluation of nematicides for control of Southern and Guava Root Knot Nematode in sweetpotato, 2019. Plant Disease Management Reports: in press.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2021
Citation:
Collins H., Adams M. L., Quesada-Ocampo L.M. (2021) Evaluation of nematicides for control of Southern and Guava Root Knot Nematode in sweetpotato, 2019. Plant Disease Management Reports: submitted.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Sandoval-Ruiz R., Jones M. A. and Grabau Z. J. (2021) Efficacy of fumigant nematicides for managing southern root-knot nematode in Florida cucumber, 2020. Plant Disease Management Reports 15:N047
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Liu C., Jones M. A., and Grabau Z. G. (2021) Impact of nematicide application on root-knot nematode management in Florida fall watermelon, 2019. Plant Disease Management Reports 15:N50.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Wolday Tsegay M., Jones M. A., and Grabau Z. G. (2021) Root-knot nematode management by nematicide application in Florida watermelon, 2020. Plant Disease Management Reports 15:N51.
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Progress 09/01/19 to 08/31/20
Outputs Target Audience:The target audiences reached by our efforts during thie reporting period werefarmers, breeders, germplasm curators, extension specialists andagents,university collaborators,USDA collaborators, and our advisory board. Changes/Problems:CHANGES OR PROBLEMS North Carolina State University: Progress in some objectives has been delayed due to coronavirus-related restrictions but we are making good progress towards objective completion and we do not expect any issues in performing project activities as proposed. USDA-ARS: The USVL and USDA-ARS as a whole was shut down due to the COVID 19 pandemic on March 31st, 2020. This has been a serious setback for the project and the completion of all milestones and goals at the USVL has been delayed for the past 6 months. Clemson University: Survey efforts, training programs and grower awareness meetings have been severely curtailed by travel and meeting restrictions due to COVID 19. University of Florida: UF shutdown due to COVID 19 delayed progress with this project. Sweetpotato acreage was projected to be down this year in Florida, so we will likely shift some planned sweetpotato samples to other crops such as Irish potatoes.? What opportunities for training and professional development has the project provided?NCSU: Faculty, technicians, postdocs, graduate students, and undergraduate students have received training in nematode biology and management through this project. Some personnel in our groups that are not directly supported by the project have also benefited and learned from the activities performed in our programs. Early-career scientists from underrepresented backgrounds have been effectively engaged in the project. USDA-ARS: A post-doc (Dr. Lesley Schumacher) was hired to perform the M. e. screening experiments at the USVL and had the opportunity to help select germplasm for future screening before she received a permanent appointment at another USDA-ARS Unit in August. A master's student (Julianna Culbreath) helped to set up the screening experiments for both pepper and sweetpotato. CU: A field day was held at the Orangeburg County Test site with 12 growers, consultants, and agents attending. One-on-one visits were made with a total of 20 growers and agents in Aiken, Bamberg, Barnwell, Calhoun, Newberry, and Orangeburg Counties. Agudelo conducted the Plant Parasitic Nematode Identification course in December of 2019 with 23 participants from across the country. UF: The bioscientist on this project learned to identify root-knot nematode species using PCR-based molecular techniques. Gaining experience with molecular techniques is something they identified as an important part of their professional training. Student training and postdoc professional development was also provided. UGA: A Postdoctoral Associate (Dr. Fereidoun Forghani) was able to assist in molecular detection of root-knot nematodes How have the results been disseminated to communities of interest?NCSU: We have presented results from this project to stakeholders at several extension venues such as the annual NC Sweetpotato field day, the NC Vegetable Growers Association Ag Expo, and the greenhouse vegetable production agent training. We have also presented at scientific conferences such as the National Sweetpotato Collaborators Group Annual Meeting, the Annual Southern Division American Phytopathological Society Meeting, and the American Phytopathological Society Annual Meeting. Quesada provided diagnostics and disease management recommendations for 95 in 2019 and 60 in 2020 vegetable crop samples submitted to the NC State Plant Disease and Insect Clinic. Quesada has also been involved in providing disease management recommendations through oral presentations, social media (Twitter: 2,962 (lab) + 1,369 (Quesada) followers, Facebook: 847 followers, LinkedIn: 2,176 followers). Quesada was also involved in an agent training about diagnostics and control of vegetable diseases in greenhouse production. Quesada, Thiessen, and Gorny have presented results as oral talks or posters at scientific conferences such as the National Sweetpotato Collaborators Group Annual Meeting, the Annual Southern Division American Phytopathological Society Meeting, and the American Phytopathological Society Annual Meeting. Gorny was involved with and provided content for agent training in biology and management of nematodes in vegetable production. Thiessen was also involved in providing content for agent and stakeholder trainings for rotational crop nematode management. Quesada has generated disease management publications such as the NC Agricultural and Chemicals Manual, the Southeastern US Vegetable Crop Handbook, and the Sweetpotato root knot nematode fact sheet. Quesada supported three demonstration field experiments in 2019 and one in 2020 to train growers and agents in the use of chemical control and tolerant varieties for management of M. e.. Quesada has presented results from this project to stakeholders at several extension venues such as the annual NC Sweetpotato field day, the NC Vegetable Growers Association Ag Expo, and the greenhouse vegetable production agent training. Gorny has contributed to relevant sections of the NC Agricultural and Chemicals Manual and the Southeastern US Vegetable Crop Handbook. Gorny has presented results and instruction in nematode management to stakeholders at extension venues including the NC Sweetpotato field day, Organic Commodities and Livestock Conference, and regional production meetings. Gorny has created two extension videos on M. e. in sweetpotato that have been posted to the NC State Extension website and YouTube channel. Thiessen has generated disease management publication materials including the NC Agricultural and Chemical Manual, NC Cotton Production Guide, NC Soybean Production Guide, the cotton root knot nematode fact sheet, and the soybean root knot nematode fact sheet. Thiessen has also presented results from this project to stakeholders at county extension meetings in January and February of 2020 to train stakeholders on chemical and management of rotational crops. CU: Survey results and the damage potential of M.e. were presented to growers, agents, and industry personnel at the S.C. State Cotton meeting (125+ attendees), the Savannah Valley Cotton Production Meeting (75 attendees), Edisto REC Fall Field Day (50 attendees), the 2019 Certified Crop Advisors training meeting (30 attendees) and to meetings of the S.C. Cotton and Soybean Boards (25 attendees). We have also presented at scientific conferences such as the National Sweetpotato Collaborators Group Annual Meeting and the Annual Southern Division American Phytopathological Society Meeting. UF: Most outreach has occurred with extension agents by direct contact or participating in regular agriculture update weeks. UGA: The results of the project have not yet been communicated with growers and the agricultural community. However, outreach activities have been done at multiple county grower meetings in GA and at the Southeast Regional Fruit and Vegetable Conference (Savannah, GA) on the importance of Meloidogyne e. as a potential threat to agricultural crops. What do you plan to do during the next reporting period to accomplish the goals?NCSU: Quesada will continue greenhouse experiments to determine vegetable crops at risk of M.e. infection and weeds that could serve as a green bridge for this nematode. Quesada, in collaboration with Gorny, will also continue field experiments to evaluate chemical control options for management of M.e. Thiessen will continue with rotational crop experiments. Quesada, Gorny, and Thiessen will continue efforts to disseminate findings of this project to stakeholders. USDA-ARS: Another post-doc will be hired to perform the M.e. screening experiments at the USVL. Split-root screening experiments will be used to continue the evaluation of the putatively resistant pepper lines until at least one line with true-breeding resistance is generated. Selected cucurbit germplasm will be obtained from GRIN and high throughput screens for resistance will be initiated. CU: County agents in the Coastal Plain of SC will be solicited in person to submit nematode samples from cotton, soybean, sweetpotato and vegetable fields with a history of root-knot nematode problems. Drs. Mueller and Ahmed will conduct in-person surveys of sweetpotato production fields in Bamberg, Darlington, Florence and Orangeburg Counties. Between the two efforts 75 to 100 samples from problem fields should be processed. Nematodes will be extracted and speciation will be performed at the newly created Edisto Nematode Laboratory at the Edisto REC. Regarding objective 5, efforts to educate and disseminate knowledge to target audiences will be increased via web and print resources. UF: We will analyze data from the experimental trials in NC and other states to identify cost-effective treatments in controlling M.e. We will also propose a supply and demand model to evaluate the potential impact of M.e. on the specialty crop industry. We plan to continue surveying for M.e. In particular, we are looking for suitable M.e.-positive sites to conduct field trials on M.e. management. We will also set up a greenhouse nematicide trial with M.e., and evaluate cover crops for host status. UGA: Soil and root samples will be obtained from other counties in the state and processed for potential detection of M.e.
Impacts What was accomplished under these goals?
We have increased our knowledge of incidence, distribution, and genetic variability of the invasive M.e. in the southeastern US. All states involved have engaged in systematic surveying of symptomatic crops and have identified M.e. in 3 states - FL, SC, and NC. These results help inform state-level quarantine measures.We identified sources of resistance for germplasm development. USDA has done extensive screening of accessions in cucurbit and solanaceous crops. Promising materials will be made available for breeders to incorporate into elite varieties.We also evaluated non-host rotation options and other management tactics including the use of nematicides. NCSU and UF assessed the efficacy of nematicides, cover crops, and rotational crops. Findings will be critical to improve integrated pest management strategies. Obj 1. Study the prevalence and distribution of M.e. and characterize the genetic variability CU: Fifty-six cotton and peanut fields sampled in Bamberg Co. were positive for M. incognita. A second survey in Orangeburg Co. with very high reproduction and galling on SRK resistant soybean varieties tested negative for M.e. and positive for M. incognita. In a third project 14 soybean fields with a history of severe galling and plant mortality, two populations were tested and both came back as M. arenaria. Plots comparing SRK resistant and susceptible soybean cultivars have been established in fields with a history of root-knot problems in Marion and Orangeburg Co. and two fields in Florence Co. Clemson hired a postdoc to process samples and start greenhouse trials. UF: Until we identify suitable field sites to conduct M.e.-specific management trials, we continue to work with other root-knot nematode species which provide preliminary data about tactics that may work for M.e. Samples were collected from 4 counties in central FL from 22 farms comprising 25 different plant species. A total of 122 female individuals were identified to species level. M.e. was found on 6 farms in 14 plant species (basil, garden egg, luffa, malaba spinach, perila, pumpkin, sweet potato, jude plant, bean, hot pepper, squash, eggplant, okra, red beet). Other root-knot nematode species found were M. incognita, M. arenaria. M. javanica, M. hapla and M. haplanaria. UGA: A total of 158 soil and/or root samples were obtained from 31 counties via submissions by UGA extension personnel. Samples were obtained from fields with symptomatic damage. Crops included cotton, peanut, corn, soybean, tobacco, sorghum, lima bean, snap bean, green bean, butter bean, cabbage, collards, cantaloupe, carrot, cucumber, okra, potato, squash, sweet potato, tomato, watermelon and pepper. Root-knot nematodes were present in 128 samples (incidence 81%), with the population density ranging from 1 to 1,640 nematodes per 100 cm3 of soil. M.e. has not been found in GA. NCSU: Susceptibility of 18 hosts to M.e. was evaluated in cucumber 'Arabian', watermelon 'Fascination' and 'Charleston gray', cabbage 'Stonehead', pepper 'Red Bull', hemp 'Felina', peanut 'Sulivan' and 'Tifguard', corn 'Early sunglow', tobacco 'K326', cotton 'Deltapine 1646', soybean '7310RY' and 'P5018RX', winter wheat 'Kaskia', sudangrass 'Piper', and the weeds palmer amaranth, yellow nutsedge, and broadleaf signalgrass. M.e. was able to reproduce on all plants. Two watermelon varieties, cabbage, pepper, one soybean variety, and tobacco were significantly infected with M.e. Broadleaf signalgrass, corn, one peanut variety, sudangrass, and nutsedge were less susceptible to M.e. and considered poor hosts. Gorny screened 9sweetpotato genotypes against two populationsfrom NC: 'Beauregard', 'Covington', 'Centennial', 'Jewel', 'Murasaki-29', 'Tanzania', 'Dimbuka-Bukulula', 'Bwanjule', and Tib-11. Obj 2. Evaluate and develop vegetable germplasm with resistance against M.e. USDA-ARS: Eighty-six wild pepper Plant Introduction (PI) lines were screened for resistance to M.e. No line showed resistance across all 4 replicates, but 7 individual plants showed little to no infection. The stems of these plants were propagated for seed, and inoculated split-root experiments have been initiated to confirm this resistance and generate true-breeding lines that will provide breeding material. Additionally, 384 sweetpotato PIs were selected based on available genotype and phenotype data for screening with M.e. and eventual GWAS analysis. An experiment was initiated to quantify the effect of M. e. resistance on the development of sweetpotato storage roots. Obj 3. Evaluate the efficacy of rotations, cover crops, and nematicides NCSU: Three trials were conducted in 2019 (Meadow, Bailey, and Pinceton) and one in 2020 (Stancil's Chapell) to evaluate chemical and host resistance control options. The sites in Bailey and Princeton had variable nematode counts with the non-treated control showing low nematode pressure. Meadow had more uniform nematode pressure and showed significant control of M.e. by Telone II + Velum Prime (current recommendation) and K-PAM. In addition, varieties 'Murasaki 29' and 'Jewel' showed lower nematode damage than 'Covington'. Rotational crop trials were established in Johnston Co. following sweetpotato evaluating two cultivars of soybean (RKN susceptible and resistant) and cotton (RKN susceptible and resistant). Treatments (Propulse foliar broadcast, Velum in furrow, and Velum + Propulse) were applied to each plot and are currently being evaluated. UF: An invitro assay wasconducted evaluating the efficacy of different nematicides (oxamyl, fluensulfone, fluopyram, fluazaindolizine and Burkholderia toxins) on M.e. juveniles. Obj 4. Assess the costs and returns of management tactics UF: A spatial risk analysis across FL has been conducted to evaluate the vulnerability to economic loss due to M.e. Each county is analyzed based on its crop mix to measure its vulnerability to nematode outbreak or establishment. We also analyzed major crops across FL, GA, SC, and NC which will provide macro-level information for nematode management in these states. The results emphasize the importance of interstate cooperation to control and eliminate the impact of M.e. FL is at great risk of large economic losses if M.e. is established because manymainspecialty crops are susceptible. The counties that are more vulnerable are in Northwest and Southeast regions. Obj 5. Develop print and web-based materials A project manager was hired in October 2019 and has led team efforts to accomplish objective 5. To initially elicit input from growers and other audiences as to the resources they would most prefer and likely use, our team distributed surveys at two professional conferences. A total of 41 responses were received from primarily growers (>55%), some researchers (~10%), and other professionals. Most rely on information from extension agents, websites, newsletters (via email), and professional conferences. Most were interested in information regarding management strategies and distribution maps, and preferred that information be in written or audio/visual format. We increased project awareness through the creation of a project name (FINDMe: Focused INvestigations on Distribution and management of Meloidogyne enterolobii), logo, branding guide, slide deck template, and ad in the 2020 Southern Vegetable Handbook. In addition, the team has developed a website (https://www.findmenematode.org/) and twitter account (https://twitter.com/FINDMeNematode) to increase awareness, educate target audiences, stay connected with other researchers, and disseminate knowledge generated. A listserv, email address (findmenematode@gmail.com), and question form on our website will allow growers to connect to the project team and gain insight from experts.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Wong T. S. and Quesada-Ocampo L. M. (2020) Evaluation of SDHIs for control of southern root-knot nematode and fungal pathogens in watermelon. Phytopathology 110:S1.20.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Ye W, Schwarz T., Davis E. L., Thiessen L. D., Quesada-Ocampo, L. M., and Gorny A. M. (2020) Occurrence of the root-knot nematode Meloidogyne enterolobii infecting sweetpotato in North Carolina, United States. Phytopathology 110:S1.2.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Collins H., Adams M. L., Parker B., and Quesada-Ocampo L. M. (2019) Evaluation of nematicides for control of Southern and Guava Root Knot Nematodes in sweetpotato, 2018. Plant Disease Management Reports 13: N030.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Collins H., Adams M. L., Parker B., and Quesada-Ocampo L. M. (2019) Evaluation of nematicides for control of Southern Root Knot Nematodes in sweetpotato, 2018. Plant Disease Management Reports 13: N031.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Keinath, A.P., W. P. Wechter, W. B. Rutter and P. Agudelo. 2019. Cucurbit rootstocks resistant to Fusarium oxysporum f. sp. niveum remain resistant when co-infected by Meloidogyne incognita in the field. Plant Disease 103:1383-1390.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2020
Citation:
Rutter, W. B., Wadl, P. A., Mueller, J. D. and P. Agudelo. 2020. Identification of Sweetpotato Germplasm Resistant to Pathotypically Distinct Isolates of Meloidogyne enterolobii from the Carolinas. Plant Disease (under review).
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Rutter, W., A. Skantar, Z. Handoo, J. Mueller, S. Aultman and P. Agudelo. 2019. Meloidogyne enterolobii found infecting root-knot nematode resistant sweetpotato in South Carolina, United States. Plant Disease 103: 775.
- Type:
Other
Status:
Published
Year Published:
2020
Citation:
Quesada-Ocampo L. M. (2018) Sweetpotato root knot nematode.Vegetable Pathology Factsheets. NC State Extension Publications. URL: https://content.ces.ncsu.edu/sweetpotato-root-knot-nematode. Revised 2020.
- Type:
Other
Status:
Published
Year Published:
2019
Citation:
Joyce, A.L. and Thiessen, L.D. (2019) Root Knot Nematode of Soybean. Soybean Disease Information. NC State Extension Publications. URL: https://content.ces.ncsu.edu/root-knot-nematode-of-soybean?x=18774
- Type:
Other
Status:
Published
Year Published:
2019
Citation:
Rosado Rivera, Y.I. and Thiessen, L.D. (2019) Root Knot Nematode of Cotton. Cotton Disease Information. NC State Extension Publications. URL: https://content.ces.ncsu.edu/cotton-root-knot-nematodes?x=22187
- Type:
Websites
Status:
Published
Year Published:
2020
Citation:
https://www.findmenematode.org/
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2020
Citation:
Quesada-Ocampo L. M. Population genetics and epidemiology approaches for management of re-emerging pathogens of vegetable crops. Department of Plant Pathology, University of Minnesota, St. Paul, MN, September 2020. Oral Presentation.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2020
Citation:
Quesada-Ocampo L. M. Management of re-emerging pathogens of vegetable crops through translational approaches. Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA, March 2020. Oral Presentation.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2020
Citation:
Wong T. S. and Quesada-Ocampo L. M. Evaluation of SDHIs for control of southern root-knot nematode and fungal pathogens in watermelon. Annual Southern Division American Phytopathological Society Meeting, Charleston, SC, February 2020. Oral Presentation.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2020
Citation:
Collins, H., Quesada-Ocampo, L. M. Evaluation of nematicides for control of Guava and Southern root knot nematodes in sweetpotato. National Sweetpotato Collaborators Group Annual Meeting, Nashville, TN, January 2020. Oral Presentation.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Wong T. S. and Quesada-Ocampo L. M. Sensitivity of Meloidogyne incognita, Fusarium oxysporum f.sp. niveum, and Stagonosporopsis citrulli to succinate dehydrogenase inhibitors used for control of watermelon diseases. NC State Plant Pathology Symposium, Raleigh, NC, November 2019. Oral Presentation.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Thiessen, L.D. Emerging Diseases of Cotton & Disease Management Considerations. Cotton Community Meeting, Raleigh, NC. October 2019. Oral Presentation
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Gorny A., Collins, H., and Quesada-Ocampo, L.M. Management of guava root knot nematode. North Carolina Vegetable Growers Association Ag Expo. Wilmington, NC, December 2019. Oral Presentation.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Gorny A. Managing nematodes: From sampling to control options. North Carolina Agricultural Consultants Association Fall Conference. Raleigh, NC, December 2019. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2020
Citation:
Thiessen, L.D. Grains Disease Management. Pasquotank County Grains Meeting. Smithfield, NC. February 2020. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2020
Citation:
Thiessen, L.D. Soybean Disease Management. Johnston County Grains Meeting. Smithfield, NC. February 2020. Oral Presentation.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2020
Citation:
Schwarz T., Collins H., Quesada-Ocampo, L. M. and Gorny A. Current management and control options for the aggressive root knot nematode, Meloidogyne enterolobii. American Phytopathological Society Annual Meeting, Plant Health 2020, Denver, CO, August 2020. Poster Presentation.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2020
Citation:
Ye W, Schwarz T., Davis E. L., Thiessen L. D., Quesada-Ocampo, L. M., and Gorny A. M. Occurence of the root-knot nematode Meloidogyne enterolobii infecting sweetpotato in North Carolina, United States. Annual Meeting of the Southern Division-American Phytopathological Society, Charleston, SC. February, 2020. Poster Presentation.
- Type:
Other
Status:
Other
Year Published:
2020
Citation:
Quesada-Ocampo, L. M. Cucumber diseases in the greenhouse. Greenhouse vegetable production agent training. Raleigh, NC, January 2020. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2020
Citation:
Thiessen, L.D. Soybean Disease Management. Northampton Grains Meeting. Jackson, NC. February 2020. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2020
Citation:
Thiessen, L.D. Soybean Disease Management. Hyde County Grains Meeting. Fairfield, NC. February 2020. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2020
Citation:
Thiessen, L.D. Soybean Disease Management. Beaufort Grain Meeting, Beaufort County. Bath, NC. January 2020. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2019
Citation:
Thiessen, L.D. Soybean Disease Management. Cleveland/Lincoln Grains Meeting, Lincolnton, NC. February 2019. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2019
Citation:
Thiessen, L.D. Soybean Disease Management. Guilford Grains Meeting, Greensboro, NC. February 2019. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2019
Citation:
Thiessen, L.D. Soybean Disease Management. Pasquotank Grains Meeting, Elizabeth City, NC. February 12, 2019. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2019
Citation:
Thiessen, L.D. Soybean Disease Management. Winter Grain Production Meeting, Onslow County. Jacksonville, NC. January 31, 2019. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2019
Citation:
Thiessen, L.D. Soybean Disease Management. Blacklands Road Show Production Meeting, Columbia, NC. January 30, 2019. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2019
Citation:
Thiessen, L.D. Soybean Disease Management. Winter Grain Production Meeting, Martin County. Williamston, NC. January 2019. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2019
Citation:
Thiessen, L.D. Soybean Disease Management. Blacklands Road Show Production Meeting, Chocowinity, NC. January 2019. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2019
Citation:
Gorny A., Collins H. and Quesada-Ocampo L. M. Control of rot knot nematode in sweetpotato. Sweetpotato field day. Kinston, NC, October 2019. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2020
Citation:
Gorny A. Management of the Guava root-knot and other nematodes in tobacco and vegetables. Organic Commodities and Livestock Conference. Raleigh, NC, February 2020. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2019
Citation:
Thiessen, L.D. Soybean disease management. Soybean Agent Training. Raleigh, NC. December 2019. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2020
Citation:
Thiessen, L.D. Cotton Disease Management. Cotton and Peanut Agent Training. Wilson, NC. January 15, 2020. Oral Presentation.
- Type:
Other
Status:
Other
Year Published:
2020
Citation:
Thiessen, L.D. Soybean disease management. Piedmont Soybean Field Day. Piedmont Research Station, Salisbury, NC. October 2019. Oral Presentation.
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