Source: UNIVERSITY OF CALIFORNIA, RIVERSIDE submitted to NRP
IPM OF PLANT PARASITIC NEMATODES BY BIOLOGICAL AND CHEMICAL MEANS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1018989
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Apr 12, 2019
Project End Date
Sep 30, 2023
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UNIVERSITY OF CALIFORNIA, RIVERSIDE
(N/A)
RIVERSIDE,CA 92521
Performing Department
Nematology, Riverside
Non Technical Summary
In crop production, root diseases and root rot are frequently significant constraints. They are the result of complex interrelationships with plant-parasitic nematodes, other soilborne pathogens, harmful microorganisms, and abiotic stress. Economic losses due to plant-parasitic nematodes were estimated to approximately US$130 billion worldwide and US$11 billion for the US (Becker, 2014). A realistic estimate also needs to consider additive and synergistic crop damage caused by interactions between plant-parasitic nematodes and other soilborne pathogens. In the past, soil fumigants offered effective solutions, but their future is questionable because of regulatory, environmental and economic considerations. Some nematicides have been removed from the market because of real or perceived problems with worker safety, groundwater contamination, and air pollution. There is an urgent need for effective, environmentally safe, and affordable management tools and strategies to protect crops from plant-parasitic nematodes. One goal of this project is to foster the development and use of a beneficial soil fungus that can potentially suppress two significant groups of nematodes. Root-knot and cyst nematodes that are responsible for ¾ of worldwide nematode-caused economic crop damage. They are a potential food source for several soil fungi, but we lack the knowledge to employ them effectively. While we try to gather crucial information about the ecology and efficacy of one of the more promising candidate fungi, recently three new nematicides have been developed. They constitute a much lower environmental risk than previous generations of nematicides. Preliminary data suggest that at least one or two of these compounds may be not harmful to non-target nematodes and microorganisms. That would allow a combination of biological and chemical strategies to manage plant-parasitic nematodes sustainably.
Animal Health Component
20%
Research Effort Categories
Basic
60%
Applied
20%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
21224101120100%
Knowledge Area
212 - Pathogens and Nematodes Affecting Plants;

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

Field Of Science
1120 - Nematology;
Goals / Objectives
The major goal of this project is to provide useful, fact-based information that allows my clientele to replace currently used, highly toxic soil fumigants and nematicides with novel, environmentally more benign crop management strategies.Significant constraints in California's crop production are root diseases and root rot that are frequently the result of complex interrelationships with plant-parasitic nematodes, other soilborne pathogens, harmful microorganisms, and abiotic stress. Economic losses due to soilborne pathogens and pests including plant-parasitic nematodes are typically underestimated as the attainable yield for many crops is unknown. In the past, broad-spectrum soil fumigants (incl. fumigant nematicides) offered very effective solutions for the suppression of plant-parasitic nematodes and soil-borne pathogens. The future of soil fumigants appears questionable because of regulatory, environmental and economic considerations. Many pesticides have been banned or taken off the market because of real or perceived problems with groundwater contamination, air pollution, and worker safety. Still, many growers rely on highly toxic soil fumigants and organophosphate or carbamate nematicides. US agriculture is in urgent need of reliable, safe and economic methods to mitigate plant-parasitic nematode and associated soilborne disease problems. This project addresses the goals of the University of California's mission of AES and CE by obtaining fundamental knowledge for the development and extension of agricultural practices that will ensure abundant and nutritious food supply, as well as economic and ecological sustainability for the future of California, the nation, and the world.OBJECTIVES:1. Investigate the fungal hyperparasite Hyalorbilia oviparasitica for its ability to protect root health by biological control of sedentary plant-parasitic nematodes.1.1 Analyze mode-of-action of H. oviparasitica in its ability to protect root health by interference with the life cycle of sedentary plant-parasitic nematodes.1.2 Determine the ecological parameter that influences survival, activity, and mode-of-action of H. oviparasitica.1.3 Utilize H. oviparasitica as one of several IPM modules for a holistic approach to disease control.2. Determine the utility of novel nematicides to suppress plant-parasitic nematodes and their influence on non-target microorganisms and mesofauna.• Investigate the efficacy of the three novel nematicides on various crops and plant-parasitic nematodes in laboratory, greenhouse and field trials.• Determine optimal application methodology for various annual crops (e.g., carrot, tomato)• Evaluate the effects of novel nematicides on non-target beneficial nematodes and microorganisms.
Project Methods
Objective 1.• Analyze mode-of-action of H. oviparasitica in its ability to protect root health by interference with the life cycle of sedentary plant parasitic nematodes- Novel strains of the hyperparasite will be obtained by baiting with females of H. schachtii. Biolog plates will be utilized to detect enzymes produced by H. oviparasitica grown on mature H. schachtii females and water agar.• Determine the ecological parameter that influences survival, activity, and mode-of-action of H. oviparasitica- Greenhouse trials with cabbage, H. oviparasitica, and H. schachtii will be conducted at various soil physical parameters.• Utilize H. oviparasitica as one of several IPM modules for a holistic approach to disease control.- Laboratory and greenhouse trials will determine H. oviparasitica's compatibility with novel nematicides and effect on cyst nematode control.Objective 2.• Investigate the efficacy of the three novel nematicides on various crops and plant-parasitic nematodes in laboratory, greenhouse and field trials.- In laboratory studies, the nematodes will be exposed to the nematicides at various rates. After various time intervals, the nematodes will be rinsed in deionized water and examined for activity. In greenhouse tests, the nematicides will be applied at field rates to soil infested with various plant-parasitic nematodes (e.g., beet cyst nematodes, several species of root-knot and lesion nematodes) and planted to susceptible host crops. After the appropriate incubation time, soil and/or roots will be extracted, and recovered nematodes will be enumerated. Roots will be rated for disease symptoms and plant growth data will be taken.• Determine optimal application methodology for various vegetables (e.g., carrot, tomato)- Field applications will be varied according to crop and formulation availability (e.g., mechanical incorporation, low volume (drip) chemigation, liquid or granular formulations)• Evaluate the effects of novel nematicides on non-target beneficials.- Expose free-living and entomopathogenic nematodes to various concentrations of the test nematicides. Rinse after various incubation times with deionized, sterile water. Determine LD50, ability to feed or infect.All trials will be performed according to statistical design and sample methods, and evaluated after statistical analysis (e.g., randomized complete block design, ANOVA). Results and conclusions will be delivered to audiences through my extension and outreach efforts

Progress 10/01/19 to 09/30/20

Outputs
Target Audience: The following audiences were reached: Vegetable growers (in particular,cole crop,carrot, tomato, and cucurbit growers), University of Californiafarm and IPM advisors, pest control advisors (private and industry), USDA scientists, California Department of Food and Agriculture and DPR personnel, agro-industrypersonnel, turfgrass(golf and athletic) superintendents, sugar beet and pitahaya commodity representatives, Master Gardeners, and the general public interested in plant-parasitic nematodes. I provide science-based information on integrated nematode managementthat benefits conventional and organic growers, home and master gardeners. Due to the covid-19 pandemic, almost all typical extension and outreach activities such as in-person workshops and grower meetings were canceled. I participated in several zoom meetingsto discuss issues in a broad range of topics incrop production. Furthermore, we produced a webinar on nematode issues in citrus. Other outreach efforts included phone conversations with clientele and cooperators.An invitation by the Plant Pathology Department at the Guangxi University, Nanning, China, gave me the opportunity to present a graduate student seminar entitled "Management of Plant-Parasitic Nematodes in California: Research & Extension". Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?The dissemination of the survey results had just started with the scientific publications,when all in-person meetings were shut down because of the covid-19 pandemic. Still, the two publications together were downloaded more than 2000 times and our press release was picked up by five news outlets. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? My program is focused on replacing highly toxic soil fumigants and contact nematicides with less problematic products or crop management strategies. These rely initially on newer synthetic or biologically-derived compounds, which have a much more benign mammalian and ecological toxicology profile. In the long run, they will perhaps be replaced by biological or biorational control solutions. In this project, we investigated two major cropping systems that are affected by cyst nematode parasitism. In the Imperial Valley, California's only remaining sugar beet production area, the nematodes are managed by rotation cropping with non-hosts until the pathogen's population is sufficiently reduced to return to growing sugar beets. While the system has workedwell for nearly 60 years, it denies the growers to produce the profitable sugar beets more frequently. We analyzed the occurrence of nematode-destroying fungi responsible for the cyst nematode decline and detected a clade of fungi, Hyalorbilia spp., previously shown to cause cyst nematode suppression. The second area we investigated was the intensive vegetable production between Monterey and Santa Barbara County. Despite frequent cropping to Brassica spp and other cyst nematode hosts, today, we rarely find areas with high cystnematode counts. It was different in the 1970s and 80s when the nematode disease pressure was high and soil fumigants became the tools of choice. Since 1990, California's Department of Pesticide Regulation has an extensive reporting system to track pesticide use state-wide. Three decades ago, approximately 20% of broccoli production fields along the Central California coast were treated with soil fumigants and contact nematicides to protect against cyst nematodes. Although broccoli yield has steadily continued to increase, pesticide use for nematode control has dramatically declined. By 2014, none of the coastal CA broccoli fields were treated with soil fumigants or contact nematicides.Preliminary data suggest that growers reduced their nematicide usage because of a natural decline in the cyst nematode population. Our investigations found that those soils harbor a diverse population of nematode-parasitic fungi, including Hyalorbilia spp. that might be suppressing cyst nematodes below a damaging threshold. The impact of these findings is two-fold. First, it underlines the importance of soil sampling analysis to determine cyst nematodes' density before using expensive and potentially harmful soil pesticides. We found very few fields with cyst nematodes that might cause significantyield reductions. Second, population dynamics of nematodes and associated microorganisms should not be considered static but frequently changing in response to management changes. Goal 1.1We analyzed the mode-of-action of three different Hyalorbilia strains that originated from other nematode hosts. Although each strain attacked and parasitized white (young) sugar beet cyst females, only one killed the non-differentiated eggs inside their bodies. That strain was isolated from a parasitized egg of sugar beet cyst nematodes. Furthermore, the younger the eggs, the higher was the destruction efficacy(Smith Becker et al., 2020). Goal 1.2 In both surveys, Hyalorbilia spp. were the most dominant clade (Witte et al., 2020;Chen et al., 2020). Goal 2.1 We investigated the efficacy of the novel nematicide fluazaindolizine against several important plant-parasitic nematodes. In our previous trials, it was an excellent nematicide against root-knot nematodes but its spectrum of activity was not furtherexplored. Our current research showed that sublethal concentrations sufficiently inhibited movement and possibly feeding of the infective stages to prevent or reduce root penetration and reproduction (Wu et al., 2020). Fluopyram solved a geographically limited but economically significant disease problem in Poa annua turfgrass. Since the 1970, several of California's most famost golf courses suffered from severe damage by the Pacific stem gall nematode. Our research showed that a single application of the novelnematicideprevented season-long the induction of stem galls by the nematode (Petelewicz et al., 2020).

Publications

  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Wu, H.Y., De Oliveira Silva, J., Smith Becker, J., and Becker, J.O. 2020. Fluazaindolizine mitigates plant-parasitic nematode activity at sublethal dosages. Journal of Pest Science 94:573583. Doi:10.1007/s10340-020-01262-2.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Witte, H., Jiue-in Yang, J.-I., Logan, G.D., Colindres, N.B., Peacock, B.B., Smith Becker, J., Ruegger, P.M., Becker, J.O., and Borneman, J. 2020. Hyalorbilia oviparasitica clade detected in field soils cropped to sugar beets and enriched in the presence of Heterodera schachtii and a host crop. PhytoFrontiers 1: 13-20. DOI:10.1094/PHYTOFR-07-20-0005-R.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Smith Becker, J., J. Borneman, and J.O. Becker 2020. Effect of Heterodera schachtii female age on susceptibility to three fungal hyperparasites in the genus Hyalorbilia. Journal of Nematology 52: 1-12. DOI: 10.21307/jofnem-2020-093.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Chen, Y.-Y., Koike, S.T., Logan, G.D., Drozd, C., De Oliveira Silva, J., Smith Becker, J., Loffredo, A., Wu, H., Ruegger, P.M., Becker, J.O., and Borneman, J. 2020. Detection of nematophagous fungi from Heterodera schachtii females using a baiting experiment with soils cropped to Brassica species from Californias central coast. PhytoFrontiers 1: 4-12. DOI:10.1094/PHYTOFR-07-20-0009-R.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Petelewicz, Pawel, Orlinski, Pawel M., Schiavon, Marco, Mundo-Ocampo, Manuel, Becker, J. Ole, and Baird, James H. 2020. Fluopyram controls shoot-galling caused by Anguina pacificae and improves turf quality in annual bluegrass putting greens. HortTechnology 30: DOI:10.21273/HORTTECH04680-20.


Progress 04/12/19 to 09/30/19

Outputs
Target Audience:During the reporting period, I gave several presentations and field days thatincluded University of California farm advisors, private pest control advisors (PCAs), Cal State University researchers, students, and representatives from agribusinesses,USDA personnel, crop commodity boards, and growers. Efforts included participation in classroom and field excursion instructions(University of California, Riverside,PLPA 265, May 1;PLPA 240, June 3;September 17, 2020; International Education Programs,UC Riverside Extension Center, August 2, 2019), and conductingfield days for growers and ag-industry(UC South Coast Research & Extension Center,July 29;August 9;September 14, 2019). Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The greenhouse and field trials provided training opportunities for two Assistant Specialists and a Student Assistant. It included trial methodology, pesticide application technology, safety training, and trial evaluation techniques. How have the results been disseminated to communities of interest?The results have been disseminated primarily through presentation and field days. Additional outreach talks were given during the fall of 2019and are scheduled for the following spring. During this review period, I increased my interactions with UCR and other students.Many of them, even those in crop-related disciplines,are blissfully ignorant about applied agricultural research. Other target groups for my outreach activities have been growers of specialty crops who are in our area often represented by first-generation immigrants from Asia and Central America. UC Riverside,PLPA 240 Field Plant Pathology, visit of 9 students and Prof. G.Vidalakis to nematicide trials at SCREC, September 17, 2019. University of CaliforniaCooperative Extension/ANR Pitahaya Festival, SCREC, September 14, 2019. Hands-on presentation: Nematode issues in Pitahaya production. Field day, South Coast Research and Extension Center, Irvine, CA, August 9, 2019. "Novel nematicides: field experiences in California." An undergraduate student group from Southwest University, Chongqing,China. Organized by Nicholas Macias-Williams, International Education Programs,UC Riverside Extension Center, August 2, 2019. "Plant-parasitic nematodes in CA Agriculture" (2 hr presentation with discussion, 20 students). (invited presentation) Presentation and field day, South Coast Research and Extension Center, Irvine, CA, July 29, 2019. "Experiences with novel nematicides." UC Riverside, PLPA 240, Field Plant Pathology Launch Meeting, June 3, 2019. "Nematology in Cooperative Extension" (invited presentation, discussion) UC Riverside, PLPA 265, Spring 2019. Colloquium on the Principles of Plant Pathology. May 1, 2019. "A career in Cooperative Extension." (invited 1 hr lecture w/ discussion). 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. New taxonomic and epidemiological data suggestthat our biocontrol strain UCRDo50 is quite different from the type strain Hyalorbilia oviparasitica (formerly Dactylella oviparasitica). It is most certainly a novel species. 1.1 AllHyalorbilia sp. strains in our collection, some of which were obtained from culture collections (ATCC, CBS, etc.)parasitizeHeterodera schachtii females in vitro, but only UCRDo50 reduces hatch of its second-stage juveniles. Objective 2. 2.1 The three nematicides fluopyram,fluazaindolizine, and fluensulfone were evaluated for their efficacy against root-knot nematodes (Meloidogyne incognita) in greenhouse andfield trials with tomato and fresh market carrots, respectively.All nematicide treatmentsreduced the root galling when compared to the non-treated control.

Publications

  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Silva, Juliana de Oliveira, Angelo Loffredo, Mara R�bia da Rocha, and J. Ole Becker 2019. Efficacy of new nematicides for managing Meloidogyne incognita in tomato crop. Journal of Phytopathology 167: 295-298. DOI:10.1111/jph.12798
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Becker, J.O., A. Ploeg, and J.J. Nu�ez 2019. Multi-year field evaluation of fluorinated nematicides against Meloidogyne incognita in carrots. Plant Disease 103: 2392-2396. DOI:10.1094/PDIS-03-19-0489-RE
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Ploeg, A., S. Stoddard, and J.O. Becker 2019. Control of Meloidogyne incognita in sweetpotato with fluensulfone. Journal of Nematology 51:1-8 DOI:10.21307/jofnem-2019-018
  • Type: Websites Status: Published Year Published: 2019 Citation: Becker, J.O., and B. Westerdahl 2019. Citrus: Nematodes. Pp. 183-185. In: UC IPM Pest Management Guideline: Citrus, UC ANR Publication 3441, Publication URL: http://www.ipm.ucdavis.edu/PMG/selectnewpest.citrus.html (major revision).