Source: UNIVERSITY OF CALIFORNIA, RIVERSIDE submitted to
MANAGING PLANT MICROBE INTERACTIONS IN SOIL TO PROMOTE SUSTAINABLE AGRICULTURE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1003854
Grant No.
(N/A)
Project No.
CA-R-NEM-6082-RR
Proposal No.
(N/A)
Multistate No.
W-3147
Program Code
(N/A)
Project Start Date
Aug 29, 2014
Project End Date
Sep 30, 2018
Grant Year
(N/A)
Project Director
Becker, OL.
Recipient Organization
UNIVERSITY OF CALIFORNIA, RIVERSIDE
(N/A)
RIVERSIDE,CA 92521
Performing Department
Nematology, Riverside
Non Technical Summary
Root diseases are important constraints in crop production in warmer climates such as California. The problems are often the consequence of intricate interrelationships among soilborne pathogens (incl. plant parasitic nematodes), other deleterious microorganisms and predisposing abiotic stress. Economic damage caused by these factors are notoriously underestimated, as attainable yield for many crops is not known. In the US financial losses due to parasitic nematodes are conservatively estimated at $12 billion per year; for California nematode-caused crop damage exceeds $1.5 billion annually. Both conventional and organic crop production have considerable nematode problems in California. New methods of nematode management are urgently needed as regulatory restrictions have severely limited the choices in chemical nematode control for conventional production. A particularly important aspect for California's diverse agriculture and abundance of "minor" crops is that registration cost for plant protection compounds is often prohibitive for all but major crops. Organic growers on the other hand have even fewer options available. In addition to the multitude of current nematode problems, a number of invasive nematode pests present a real threat to California's agriculture and horticulture. Cultural practices provide varying protection and are often economically not feasible. Resistant cultivars are available only for a limited number of crops and nematode species. The future of genetically engineered crops is doubtful at best. Consequently, this project seeks to utilize the lessons learned in developing a new set of safe, practical and effective tools for plant protection against nematode pests. Field sites in which plant pathogens, including plant parasitic nematodes occur but fail to thrive, to cause crop diseases and significant losses are valuable resources for the isolation of potential biological control organisms. They also serve as real world laboratories to study organismal interactions between plants, pathogen, antagonists and associated microorganisms. We have discovered and characterized several plant parasitic nematode-suppressive field sites that has lead to the identification of potential biological control agents. Consequently we obtained evidence of their involvement in the suppression of plant parasitic nematodes. These discoveries are significant as they have lead not only to novel models in managing nematode-caused plant diseases but in the development of a commercial biorational/biocontrol product for seedling protection against endoparasitic nematodes.
Animal Health Component
0%
Research Effort Categories
Basic
20%
Applied
70%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
21624101120100%
Knowledge Area
216 - Integrated Pest Management Systems;

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

Field Of Science
1120 - Nematology;
Goals / Objectives
To identify and characterize new biological agents, microbial community structure and function, naturally suppressive soils, cultural practices, and organic amendments that provide management of diseases caused by soilborne plant pathogens. To understand how microbial populations and microbial gene expression are regulated by the biological (plants and microbes) and physical environment and how they influence disease. Provide outreach, education, extension and technology transfer to our clients and stakeholders- growers, biocontrol industry, graduate and undergraduate students, K-12 students and other scientists. Implement sustainable management strategies for soilborne pathogens that are biologically based and are compatible with soil health management practices.
Project Methods
We have detected nematode-suppressive sites based on various bioassays that compare the population development of the target nematode population in a heat-treated, re-infested soil to a non-treated soil (Westphal and Becker, 1999, 2000, Pyrowolakis et al., 2002, Borneman and Becker, 2007). Soil samples will be collected from various geographic areas in California where the plant-parasitic nematodes occur. Each soil sample will be divided and one half will be exposed to a biocidal treatment (Becker et al., 1998). Each subsample will be infested with freshly hatched 2nd stage juveniles of the nematode and planted to a susceptible host. Significant population differences after approximately 1000-degree days will be an expression of the presence of one or more nematode population-suppressive agent/s. Identification of potential biocontrol microorganisms will be based on traditional media-based culture techniques as well as on methods of nucleic acid-based detection. In collaboration with J. Borneman's lab that developed an oligonucleotide fingerprinting of ribosomal RNA genes, we will map the total community of rhizosphere and/or nematode-parasitizing microorganisms. This array-based, culture-independent method allows analysis of microbial community composition by sorting rDNA clones into taxonomic clusters (Valinsky, 2002a,b). Microorganisms of interest will be isolated, stored and evaluated for their efficacy against plant parasitic nematodes. For sugar beet cyst nematodes we will continue to target California's Imperial Valley where the sugar beet factory Holly Sugar has offered cooperation in sampling the grower's fields. During harvest, the factory is routinely collecting beet dump samples that each represents an area of approximately 5 acres. These samples are processed to determine the cyst density on which planting decisions are made for the following seasons. We will obtain duplicate samples to probe for nematophagous fungi such as Dactylella oviparasitica (Yang et al., 2012). We will follow three strategies with respect to the suppressive microorganisms. The first is to utilize the natural suppressive soil and inflict changes that affect the suppressiveness of the soil. By following the population development of the nematodes and the population dynamics of the identified beneficial microorganisms we expect to gain a better understanding in the factors that govern the interaction of those organisms. We will focus on soil physical factors such as soil matric potential, pH and structure/organic matter content. In the second approach we will re-introduce the identified beneficial organisms into conducive and undisturbed soils to follow their population dynamics in relation to the nematode population dynamics. For this purpose, we have developed a carrier for Dactylella that will allow the soil amendment of the fungus without introducing excess nutrients (Smith Becker et al., 2014). In addition we will explore whether the suppressiveness is limited to the original target nematode pest or if the inhospitality of the soils affect other nematode species. This is of special interest in view of the threat of invasive species, especially those that are capable of surviving long periods without hosts or desiccation (e.g. cyst nematodes). We are planning to obtain USDA/CDFA permits to test suppressive soils and their potential biocontrol agents against cyst nematodes that are currently not present in California such as soybean and potato cyst nematodes. Differences in the response to different pests should provide further insights into the mode-of-action of the beneficial organisms. Our third strategy will explore combinations of biocontrol organisms with biorational or synthetic nematicides, in particular applied as seed treatments. Preliminary data have shown that the combination of both components lead to additive or even synergistic effects that increase the efficacy of the protection (Becker 2013, 2014). Similar additive benefits are expected when combining resistant or tolerant cultivars with biologicals and/or biorationals.ReferencesBecker, J.O., H.D. Ohr, N.M. Grech, M.E. McGiffen, Jr., and J.J. Sims. 1998. Evaluations of methyl iodide as a soil fumigant in container and small field plot studies. Pesticide Science 52:58-62.Becker, J.O. 2013. Disease protection against sedentary plant parasitic nematodes through combination products with agrochemical and biological control agents. J. Nematology 45:282.Becker, J.O. 2014. Plant health management: Crop Protection with Nematicides. In: Encyclopedia of Agriculture and Food Systems (ed. N. van Alfen), Elsevier (in press).Borneman, J., and J.O. Becker 2007. Identifying microorganisms involved in specific pathogen suppression in soil. Annual Review of Phytopathology 45:153-72.Smith Becker, J., H. Witte, and J.O. Becker 2014. Peat as a suitable growth media and carrier for Dactylella oviparasitica. Proceedings 6th International Congress of Nematology, p. 240.Pyrowolakis, A., A. Westphal, R.A. Sikora, and J.O. Becker 2002. Identification of root-knot nematode suppressive soils. Applied Soil Ecology 19:51-56.Valinsky, L., G. Della Vedova, T. Jiang, and J. Borneman 2002. Oligonucleotide fingerprinting of ribosomal RNA genes for analysis of fungal community composition. Appl. Environ. Microbiol. 68:5999-6004.Valinsky, L., Della Vedova, G., Scupham, A. J., Alvey, S., Figueroa, A., Yin, B., Hartin, J., Chrobak, M., Crowley, D. E., Jiang, T., and Borneman, J. 2002. Analysis of bacterial community composition by oligonucleotide fingerprinting of rRNA genes. Appl. Environ. Microbiol. 68:3243-3250.Yang, J., S. Benecke, D.R. Jeske, F. Rocha, J. Smith-Becker, P. Timper, J.O. Becker, and J. Borneman 2012. Population dynamics of Dactylella oviparasitica and Heterodera schachtii: toward a decision model for sugar beet planting. Journal of Nematology 44:237-244.Westphal, A., and J.O. Becker. 1999. Biological suppression and natural population decline of Heterodera schachtii in a California field. Phytopathology 89:434-440.Westphal, A., and J.O. Becker. 2000. Transfer of biological soil suppressiveness against Heterodera schachtii. Phytopathology 90:401-406.

Progress 08/29/14 to 09/30/18

Outputs
Target Audience:My target audiences included growers, University of California farm, horticultural and integrated pest management advisors, private pest control advisors, California Department of Food and Agriculture personnel, USDA scientists, agribusiness personnel, commodity representatives and others that were affected by or interested in plant-parasitic nematodes and associated microorganisms. I conducted research and provided useful information on biological, biorational, and chemical suppression of plant-parasitic nematodes that benefits conventional and organic growers, turf superintendents, landscapers, home and master gardeners. Many of my audiences are from various ethnic and educational backgrounds. The topic of biological control is especially relevant for small farm and home growers who typically are not allowed to use nematicides or do not have the financial resources. This project is aimed at reducing the use of potentially hazardous materials that require strict safety standards during handling and application. These regulations are often compromised due to language and/or education challenges. Many small farmsare operated in Southern California by minorities and underrepresented groups. My extension and outreach efforts include presentations at grower meetings such as commodity type gatherings, PCA educational programs (e.g., PAPA, CAPCA), and our Annual California Statewide Nematology Workshop. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?All my field trials were attended by my technician, students, postdocs and visiting scientists; sometimes even personnelfrom other labs joined my group. These are great opportunities to learn about setting up scientific trials according to specific designs. Furthermore, I provide information about the diseases, the treatments we apply, and the potential issues we must be aware of during the trial season. We also invite farm advisors, pest control advisors, and industry personnel to field days. How have the results been disseminated to communities of interest?The results have been disseminated in publications (journals, newsletters) or during presentations in commodity and grower meetings, the Annual California Statewide Nematology Workshop and Workgroup meetings, and the Annual Conference on Soilborne Plant Pathogens. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Financial losses related to plant-parasitic nematode's activities are conservatively estimated at $12 billion per year in the US and $1.9 billion in California. New techniques of nematode management are urgently needed as regulatory restrictions have severely limited the choices in chemical nematode control. Organic growers have even fewer options available. Cultural practices such as crop rotation or fallowing provide little protection when faced with root-knot nematodes that have a huge host range. Resistant cultivars are available only for a limited number of crops and nematode species. The near future of genetically engineered crops is doubtful at best. Consequently, this project's goal was to develop a new set of safe, practical and effective tools for plant protection against nematode pests. We identified field sites in which plant-parasitic nematodes occurred but failed to thrive, caused only minor crop diseases and little yield or produce quality losses. Some of these locations turned out to be valuable resources for the isolation of potential biological control organisms. They also serve as real-world laboratories to study organismal interactions between plants, fungal pathogen, plant-parasitic nematodes, and harmful as well as beneficial microorganisms. We discovered and characterized several nematode-suppressive agricultural field sites that led to the identification of biological control agents. We studied their mode-of-actions and the environmental parameters that supported or negated the suppression of cyst and root-knot nematodes. These discoveries will have a significant impact as they add to our knowledge about natural nematode population control. It will contribute to novel models in managing nematode-caused plant diseases and eventually in the development of effective commercial biocontrol products for crop protection against plant-parasitic nematodes. Accomplishments (1) To identify and characterize new biological agents, microbial community structure and function, naturally suppressive soils, cultural practices, and organic amendments that provide management of diseases caused by soilborne plant pathogens. We collected approximately 80 soil dump samples derived from sugarbeet fields in the Imperial Valley, CA. The samples were dividedand one half was pasteurized while the other remained untreated. After infestation of both soils with sugar beet cyst nematodes, a sugarbeet cyst nematode-susceptible host (cabbage) was grown in each soil. After 1300 degree days incubation in a greenhouse, females, cysts, and eggs were enumerated. A similar experimental approach was conducted with soil samples from 152 Brassica fields obtainedfrom the California coastal vegetable growing areas. In 6 soils from the Imperial Valley, the cyst nematode population density in the pasteurized, H. schachtii-infested soil exceeded by several times the one in the nontreated, infested part. In the Brassica samples, 57 tested positive for the presence of H. schachtiifemales/cysts. After treatment application, H. schachtii-infestation, and cropping for 1300 degree days, in 15 pasteurized soils the nematode population more than doubled compared to the one in the non-treated, infested part. In soils with highly significant population differences, pasteurization eliminated one or more biological factors that suppressed the nematode population in the natural soil. The suppressive soils have been frozen (-80) for further molecular analysis. We have preliminary molecular data that indicate an abundant presenceof fungi belonging to the Orbiliales. (2) To understand how microbial populations and microbial gene expression are regulated by the biological (plants and microbes) and physical environment and how they influence disease. Weutilize the naturally suppressive soil and caused disturbances that affected the suppressiveness of the soil. The second approach was to infest pasteurized soil with a particular biocontrol strain and repeat the disturbance procedure. By following the population development of the nematodes and the population dynamics of the identified beneficial microorganisms, we gained a better understanding of the factors that governed the interaction of those organisms. We primarily focused on soil physical factors such as soil temperature and pH. Our model strain was the fungus Pochonia chlamydosporia, isolated from fieldsoil at our UC Kearney Research and Extension Center at Reedley, CA. We exposed the natural and infested soil to various temperatures in water baths that were kept for 30 minutes at 25, 30, 35, 40, 45, 50, 55, 60 C. Soil samples were dilution-plated on semi-selective agar. In the second set of trials, the soil pH was adjusted to approximately 4.5, 5.5, 6.5, 7.5, 8.5 and infested with chlamydospores of P. chlamydosporia. After incubation at room temperature for 5 days, soil samplesweredilution-plated on semi-selective agar media. The fungus grew well up to 50 C and from pH 4.5 to 7.5. At pH 8.5 the radial growth was less vigorous although not completely inhibited. This is in line with various other nematode-destroying fungi. P. chlamydosporia is of special interest because it is relatively easy to grow in culture. Its wide range of growing conditions is of advantage for successful introduction as a biocontrol agent. (3) Provide outreach, education, extension and technology transfer to our clients and stakeholders- growers, biocontrol industry, graduate and undergraduate students, K-12 students and other scientists. Progress in the project was reported each year at the annual Nematology Workgroup meeting. In addition, results were presented at various grower and PCA meetings around the State. One of my graduate students participated in some of our studies. The perception of biological control has changed over the years. Particularly many California growers have a strong desire to utilize novel pest control techniques that are not based on synthetic chemicals. Unfortunately, there are few commercial biocontrol products against plant-parasitic nematodes on the market. Most of them are not very effective. However, educational events about the nature of the beneficial organisms will stimulate the demand for more efficacious products. Outreach stimulates interest and demand for increasing efforts in biological control. (4) Implement sustainable management strategies for soilborne pathogens that are biologically based and are compatible with soil health management practices. We conducted a number of carrot experiments with the seed coating abamectin. This is biologically derived nematicideis registered in various crops as a seed treatment but so far it is not available in California.Syngenta provided carrot-coated seed that contained abamectin. The carrots were seeded in plastic cups that contained a sand loam infested with Southern root-knot nematodes (Meloidogyne incognita). The cups were incubated in the greenhouse for about 8 weeks. Harvested carrots were rated for root galling on a scale 0-10. The abamectin treatment reduced galling by about 2 rating classes compared to the untreated control. This demonstrated the utilityof a nematicidal seed treatment. Typically only a small part of a grower's field requires a soil-applied nematicide. Seed treatments are effective for about 3 weeks which should be sufficient to mitigate root-knot nematode attack ofthe taproot.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Koch, E., J.O. Becker, G. Berg, R. Hauschild, J. Jehle, J. K�hl, K. Smalla 2018. Biocontrol of plant diseases is not an unsafe technology! Journal of Plant Diseases and Protection 125(2):121125. https://doi.org/10.1007/s41348-018-0158-4
  • Type: Other Status: Published Year Published: 2017 Citation: Becker, J.O., and J. Smith Becker 2017. 25 Years After the Discovery of Sting Nematodes in California: Summary of Research and Extension Efforts. 2017 UCR Turfgrass and Landscape Research Field Day Proceedings, p. 9. http://turfgrass.ucr.edu/reports/pest_management/discovery_sting_nematodes_2017.pdf
  • Type: Other Status: Published Year Published: 2018 Citation: Becker, J.O. and J. Smith Becker 2018. Important plant-parasitic nematodes in California turf grasses. 2018 UCR Turfgrass and Landscape Research Field Day Proceedings, p. 8.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Chen, Y. Y., H. Wu, A. Loffredo, R. Lobo, G. Tanizaki and J. O. Becker 2017. Susceptibility of Pitahaya Species to the Southern Root-knot Nematode. American Society for Horticultural Science National Meeting. Supplement to HortScience Volume 52(9):S435-S436.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Loffredo, A., de Oliveira Silva, J., and Becker, J. O. 2018 Fluopyram-treated carrot seed reduces seedling damage by the Southern root-knot nematode. Journal of Nematology 50: 645-646.


Progress 10/01/16 to 09/30/17

Outputs
Target Audience:The target audience reached during this reporting year included University of California CE advisors, especially those with farm, environmental horticulture and integrated pest management assignments, private pest control advisors and CA Department of Pesticide Registration-certified applicators, Master Gardeners, Federal, State and County ag officials and scientists as well as other representatives from agribusinesses including chemical and biological control industries, crop commodity boards, and growers. The strong communication among W3147 participants further expands our research and extension reach. Examples of my extension efforts include invited participation to several commodity research and pest control advisor meetings, the annual organization of the combined Conference on Soilborne Plant Pathogens/Statewide CA Nematology Workshop, field days for growers, advisors and industry representatives and interactions via phone and social media. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided training for University of California farm advisors, private pest control advisors and industry personnel who attended my presentations and our field days. I mentored one Brazilian Ph.D. student who conducted some of her thesis research in my lab. Furthermore, I advised one postdoctoral researcher from Taiwan and one visiting scientist from P.R. China. How have the results been disseminated to communities of interest?I presented our results at various grower's and workgroup meetings as well as workshops (see Other Products). Frequently, I have been asked to update the Nematode sections of the UC IPM websites (http://ipm.ucanr.edu/PMG/selectnewpest.citrus.html). Phone calls and email inquiries provided me with further opportunities to disseminate information to my clientele. I'm also the webmaster for the California Nematology Workgroup (http://ucanr.edu/sites/CA_Nematology/). What do you plan to do during the next reporting period to accomplish the goals?We will continue to investigate the cyst nematode-suppressive soils, isolate candidate microorganisms and utilize them in greenhouse tests to confirm their nematode population-suppressive activity.

Impacts
What was accomplished under these goals? California's regulatory restrictions on the use of soil fumigants have made the management of plant-parasitic nematodes extremely difficult. The continued trend to narrowly crop rotations or even monoculture and the climate change are likely to further favor the development and disease-causing activity of various plant-parasitic nematode species. We hypothesize that naturally occurring disease-suppressive soils harbor nematode-antagonistic microbes. We will analyze their mode of action as well as their ecological requirements as these are prerequisites to utilize them successfully as biocontrol agents to mitigate crop diseases. On the other hand, novel nematicides with much more favorable toxicological profiles than previous generations are clove to market introduction. We evaluate their efficacy and compatibility with integrated disease management strategies. Goal (1): Previously we had identified soils that can be classified as cyst nematode-suppressive. These soils were discovered by comparing nematode population development over time in a soil that was a) heat-sterilized or b) left untreated. The two variants were then infested with sugar beet cyst nematodes (Heterodera schachtii) and cropped for two nematode generations to a host plant. If the nematode populations remained similar in both soils, we postulate that the untreated soil did not contain nematode-suppressive microorganisms. However, if we find a significantly higher cyst nematode population in the sterilized, re-infested soil sample than in the untreated, infested sample, we suspect one or more biological organisms to be present in that latter sample. The sugar beet cyst nematodeis found in California in many Cole crop-growing areas and in the Imperial Valley in sugar beet fields. Since the temporary ban of Telone II in 1992, nematicide use in the Cole crop-producing areas has dramatically dropped. A survey of 152 randomly selected Brassica fields in the Salinas Valley and Santa Barbara County found only 1/3 of fields infested with this nematode despite typically narrow crop rotations with susceptible crops. Moreover, very few soils had H. schachtii population densities that would predict an economic crop impact. When these soil samples were tested for biological cyst nematode population-suppression, at least 15 soils tested positive. The results illustrate to growers the potential benefits of quantifying nematode populations at least every few years to avoid crop management decisions based on outdated information, hearsay or industry salesmanship. Furthermore, we found very strong evidence for widespread natural suppression that needs to be further investigated. These results which we have already presented at various meetings have served as preliminary results for a NIFA research proposal. Goal (3): During this reportingperiod I gave 13 presentations to clients and stakeholders that touched on the results of this project. Details are listed under "Other Products". Goal (4): We continued to evaluateseveral novel nematicides and biocontrol products with improved mammalian toxicity and eco-toxprofiles in various vegetable and turfgrass field trials. The commercial biological products did not show any significant activity against root-knot nematodes (M. incognita) and the Pacific shoot-gall nematode (Anguina pacificae). In contrast, amending theroot-knot nematode-infested soil with mustard seed resulted in a reduction in nematode-disease symptoms and an increase in marketable carrot yield. Similar results were obtained with 3 novel synthetic nematicides. In addition, seed-delivered nematicides mitigated the early attack of root-knot nematodes and significantly improved protection against carrot root galling and forking. Fluopyramreduced the A. pacificae population and associated shoot galls. It improved the turf quality, turfgrass biomass, and thenumber of grass shoots compared tothe non- treated control or a botanical neem product.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Baird, J., M. Schiavon, M. Mundo, and J.O. Becker 2017. Breakthrough in Managing the Pacific Shoot Gall Disease in Annual Bluegrass. 2017 UCR Turfgrass and Landscape Research Field Day Proceedings p. 8
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Baird, J.H., M. Schiavon, M. Mundo-Ocampo, and J.O. Becker 2017. Fluopyram provides effective control against Anguina pacificae in annual bluegrass. APS Pacific, Riverside, June 2017, Proceedings p. 18.
  • Type: Other Status: Published Year Published: 2016 Citation: Baird, J., and J.O. Becker 2016. Effective control of the Pacific shoot-gall nematode in annual bluegrass putting greens with IndemnifyTM (fluopyram), a new turf nematicide. Thru the Green, July-September 2016:12-15.
  • Type: Other Status: Published Year Published: 2017 Citation: Crow, W., J.O. Becker, and J.H. Baird 2017. New Golf Course Nematicides. Golf Course Management. July 2017: 66-71.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Ploeg, A., and J.O. Becker 2016. Abamectin as a microbial-derived nematicidal seed coating. 32nd Symposium European Society of Nematologists, abstract booklet p. 73
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Ploeg, A., J.O. Becker, and J. Nunez 2017. Managing root-knot nematodes in organic carrot production  an overview of California studies. International Carrot Conference, Bakersfield, CA. Abstract booklet PM-107.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Loffredo, A., J. Smith Becker, R. Fukui, and J.O. Becker 2017. Combination of microbial antagonists and a seed-delivered nematicide mitigated root-knot nematode-caused disease in tomato greenhouse and microplot trials. Journal of Nematology 49, 513
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Qiong, He, H.Y. Wu, J.S. Becker, and J.O. Becker 2017. Aspergillus japonicus strain ZW1 and its toxicity against root-knot nematodes. SON 56th Annual meeting, Williamsburg, Virginia. Abstract booklet p. 103-104


Progress 10/01/15 to 09/30/16

Outputs
Target Audience:My audience consisted primarily of CA EPA-licensed pest control advisors, both those associated with the University of California and private entities. Other clientele included representatives from agribusinesses, State and FederalInstitutions. Examples of my extension activities include active participation at commodity research meetings and workshops. I organized several field days for growers, advisors and industry representatives. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The research provided training for my postdoc and research associate in detection techniques. Our field trials offer opportunity for farm advisers, students, visiting scientists and industry collaborators to learn trial methodology, monitoring and disease scoring techniques. How have the results been disseminated to communities of interest?Results and conclusions of this project were disseminated during the following events: California EPA licensed pest control advisers (CAPCA) Ventura, Santa Paula, September 9, 2015. "Updates and control practices for nematodes of importance to Ventura County". (invited presentation). University Extension Turf Management Certificate Course, 3 hr Webinar, UC Riverside Extension, Oct 20, 2015, Riverside, CA. "Turf Management: Nematodes in California Turf". (invited presentation) 26th Annual Fall Desert Crops Workshop; El Centro, CA, Oct 29, 2015. "From suppressive soils to biological control of Heterodera schachtii" (invited presentation). First annual "Do No Harm" workshop, UC Riverside Palm Desert Center, November 5, 2015. "The Sting Nematode, a Subterranean Invasive Species in the Coachella Valley" (presentation). Multistate Research Project meeting, W3147, "Managing Plant Microbe Interactions in Soil to Promote Sustainable Agriculture", Mission Inn, Riverside, CA. Dec 6, 2015. "Evaluation of a strain of Purpureocillium lilacinum". UC Vegetable Crops Program Team Meeting, ANR Building, Davis, CA, Dec 8-9, 2015. "New crop protection products against plant parasitic nematodes." (invited presentation) Association of Applied IPM Ecologists Conference, Monterey, CA, Feb 1-2, 2016. "Nematicide revival?" (invited presentation) 62nd Conference on Soilborne Plant Pathogens & 48th Statewide CA Nematology Workshop, Kearney Research & Extension Center, March 22-26, 2016 "Nematicides - past and future" (invited presentation). Environmental Horticulture Program Team meeting, UCCE Ventura, April 18-19, 2016. "Nematodes in California turf". Vegetable Field Day, UC South Coast Research & Extension Center, Tustin, CA, July 6, 2016. "Root-knot management in vegetable crops". 55th Annual Society of Nematologists Meeting/ONTA Annual Meeting, Montreal, Canada, July 17-19, 2016. "Novel nematicides" (invited Symposium presentation) Industry Field Day, UC South Coast Research & Extension Center, Tustin, CA, July 26, 2016. "Root-knot nematode control in carrots, cucumbers and sweet potatoes". Pitahaya/Dragon Fruit Production Seminar, San Diego County Farm Bureau, Escondido, CA, August 19, 2016, "Nematode issues for Pitahaya production" Industry field day; trial results, demonstrations and discussions. UC Riverside, August 24, 2016. Turf & Landscape Day, Agricultural Operations, UC Riverside, September 15, 2016. "Nematicidal protection against the Pacific shoot-gall nematode Anguina pacificae in Poa annua greens." Pitahaya Day, Hansen Agricultural Research and Extension Center, UCCE Ventura County, September 16, 2016, "Nematode Research in Dragon Fruit Production." What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective 1: We identified a new strain of Pochonia chlamydosporiathat was isolated from parasitized eggs of Meloidogyne incognita. In preliminary greenhouse trials it suppressed the population build-up of the nematode by significantly reducing the egg hatch. Objective 3: During this year I gave 15 presentations to clients and stakeholders. Details are listed under "disseminated to communities of interest" and "products". Objective 4: We evaluated implementation of a botanical nematicide based on Neem oil at several golf courses along the California coast. Despite frequent application at high rates the product provided no protection against Anguina pacificae. In contrast, the new turf nematicide Indemnify significantly improved turfgrass growth and reduced disease symptoms.

Publications

  • Type: Other Status: Published Year Published: 2016 Citation: Baird, J., M. Schiavon, M. Mundo, and J.O. Becker 2016. A new nematicide against the Pacific shoot-gall nematode Anguina pacificae. 2016 UCR Turfgrass and Landscape Research Field Day Proceedings 25-26.
  • Type: Other Status: Published Year Published: 2016 Citation: Baird, J., and J.O. Becker 2016. Effective control of the Pacific shoot-gall nematode in annual bluegrass putting greens with IndemnifyTM (fluopyram), a new turf nematicide. Thru the Green, July-September 2016:12-15.


Progress 10/01/14 to 09/30/15

Outputs
Target Audience:The audience I have reached consisted primarily of pest control advisors, both those associated with the University of California and private entities. Other clientele included representatives from agribusinesses, State and Federal Institutions.Examples of my extention activities include active participation at commodity research meetings and workshops. This year I organized and headed the combined Conference on Soilborne Plant Pathogens/Statewide CA Nematology Workshop, as well as field days for growers, advisors and industry representatives. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The research provided training for my technician in detection techniques. How have the results been disseminated to communities of interest?The research results were disseminated during the following events: CAPCA Ventura, Santa Paula, September 9, 2015. Updates and control practices for nematodes of importance. International Plant Pathology Conference, Berlin, Germany, August 24-27, 2015. Comparative virulence of Dactylella oviparasitica strains for the control of Heterodera schachtii. Desert Horticulture Conference, Tucson, June 5, 2015. What's New With Nematodes? CAPCA Progressive Farmers Meeting, Blythe, CA, March 19, 2015. Crop protection against plant parasitic nematodes: novel approaches and agents. Nem250 Department Seminar, UC Riverside, CA, Feb 11, 2015. Anguina pacificae, a galling problem in some coastal golf courses in Northern California. Sugarbeet Annual Research meeting, Holtville, CA, January 29, 2015. Biological population suppression of sugar beet cyst nematodes. 25th Annual Fall Desert Crops Workshop 2014. El Centro, CA, November 13. Next-Generation Nematicides and Bioagents. Radio Interview with California AgNews 24/7 (http://californiaagnews.com/) (broadcast October 15, 2014) Web report interview with California Ag Today Reporter, October 16, 2014. Processing tomato field day with UCCE advisor Joe Nunez, Shafter, CA (Kern County), Oct 14, 2014."Moving forward in nematode management while avoiding past mistakes" (invited) Hands-on field day with UCCE advisor Gene Miayo, Woodland, CA (Yolo/Sacramento counties), Oct. 2, 2014. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? While Federal and State regulatory restrictions have severely limited use of soil fumigants and nematicide for conventional production, organic food production is even more constraint by the lack of economically effective methods to manage plant parasitic nematodes. Climatic change, in particular the increase of the average temperature, is likely to further favor the establishment, development, and activity of plant parasitic nematode species. Naturally occurring disease suppressive soils offer opportunities to isolate potentially beneficial microbes and to analyze their mode of action as well as their ecological requirements. These are prerequisites to utilize them successfully to mitigate crop diseases. Accomplishments (Goal 1): We have identified soils that can be classified as nematode population suppressive. Such soils were discoveredby comparing nematode population development over time in a soil that was a) pasteurized or b) left untreated. The two variants were then infested with sugar beet cyst nematodes (Heterodera schachtii) and cropped to a host plant. Was the originally soil suppressive, in a) potential nematode-deleterious microorganisms were likely eliminated and the nematode population increased unchecked. In b) the nematode population did not significantly change because of nematode-deleterious microorganisms. We identifiedBrachyphoris oviparasitica(syn.Dactylella oviparasitica) as the primary factor in a suppressive field location. Accomplishments (Goal 2): In an extensive survey of approximately 70 sugar beet fields in the Imperial Valley, 2/3 were found to contain the fungusB. oviparasitica.This fungus preferentially parasitizessedentary juveniles and young females of H. schachtii.The soil samples were divided in replicates, infested withH. schachtiiand planted with a host plant (Swiss chard). Juveniles of the nematode swell during their development in the roots until the posterior end of young females break through the root epidermis and become accessible to microbial parasites. This system served as a soil bioassay to trapB. oviparasitica. Accomplishments (Goal 3): The experiments, results and preliminary conclusions of this project were included in a number of presentations at research and grower meetings, commodity and workgroup events as well as field days (see below under dissemination of results). Accomplishments (Goal 4): During this time period there were no sustainable management strategies for soilborne pathogens implemented.

Publications

  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Yamaura, H., Y. Moriyama, J.O. Becker, and R. Fukui 2016. Soil biological and physiochemical factors limiting the growth potential of tomato seedlings grown in near-saturated soil. Soil Science and Plant Nutrition 62
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Becker, J.O., A. Ploeg, and J. Nunez 2015. Four year Southern California field assessment of new nematicides against root-knot nematodes in processing tomato. Abstract book 47th Annual Meeting of the Organization of Nematologists of Tropical America (ONTA), Varadero, Cuba, May 18-22, 2015. p. 43.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Becker, J.O. 2015. Whats New With Nematicides? Proceedings Desert Horticulture Conference, Tucson, p.6.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Ploeg, A., J.O. Becker, and J. Nunez 2015. Field and micro-plot trials on use of mustard-type crops to manage root-knot nematodes in carrot and tomato in California. Abstract book 47th Annual Meeting of the Organization of Nematologists of Tropical America (ONTA), Varadero, Cuba, May 18-22, 2015. p. 64.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Becker, J.O., A. Ploeg, and J. Nunez 2015. Control of root-knot nematodes in fresh carrot production in California. Abstract Booklet International Carrot Conference, Ontario, Canada, 2015.


Progress 08/29/14 to 09/30/14

Outputs
Target Audience: My target audiences include growers, University of California farm, horticultural and integrated pest management advisors, private pest control advisors, California Department of Food and Agriculture personnel, USDA scientists, agribusiness personnel, commodity representatives and others that are affected by or interested in plant parasitic nematodes and associated microorganisms. I conduct research and provide information on natural, biorational and chemical plant disease suppression that benefits conventional and organic growers, turf superintendents, landscapers, home and master gardener. My research and extension program promotes feasible alternatives to currently used pesticides and is aimed at reducing the use of hazardous materials that require strict safety standards. These regulations are sometimes compromised due to language and/or education challenges. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? One of the field days provided crucial training for industry representatives in getting proficiant in nematode disease ratings. How have the results been disseminated to communities of interest? During the short reporting period (8/29/2014 - 9-30-2014) I presented parts of this project at three major extension events. At a field day on September 9, 2014 at the University of California South Coast Research and Extension Center, Irvine, CA, my audience included about 12 representatives from agribusinesses. The activities included a lecture and hands-on training in assessing root knot nematode damage in melon field plots. Furthermore, we discussed the current management options and future potential for alternative products such as biological or botanical products. At the University of California Riverside Turf & Landscape Field Day on September 11, 2014, I gave 4 times a 15-minute presentation about turf grass nematodes and their management. The audience (approximately 200) was comprised of turf grass and product professionals, superintendents, breeders, landscapers, agrochemical and biocontrol industry representatives. I also participated in a tomato field day with farm advisor Joe Nunez, Shafter, CA, on September 18, 2014. Approximately 25 growers, agrochemical and nursery personnel were present, as well as a local press/radio reporter. I presented data from our field studies and discussed various options for nematode management. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Accomplishments during the reporting period include 3 field days with additional outreach opportunities by giving press/radio interviews.

Publications