Source: UNIVERSITY OF CALIFORNIA, DAVIS submitted to NRP
EVOLUTION, GENETICS, SPREAD, AND MANAGEMENT OF WEEDS IN CALIFORNIA
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1002110
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Dec 11, 2013
Project End Date
Sep 30, 2018
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UNIVERSITY OF CALIFORNIA, DAVIS
410 MRAK HALL
DAVIS,CA 95616-8671
Performing Department
Plant Sciences
Non Technical Summary
Weeds cause major economic and environmental losses in agricultural and other managed, as well as natural, ecosystems of California and the United States. Moreover, the capacity of weeds for rapid evolution to novel environments and management practices poses constant challenges for farmers and land managers. The overall goal of the proposed project is to investigate the evolutionary, genetic, and demographic processes underlying the introduction, establishment, and spread of agricultural and invasive weeds in California for the purposes of designing effective long-term weed management programs. Multiple approaches will be used to conduct the project, including field surveys, population-level sampling, population genetic and/or population genomic (depending on available funding) analyses, and genetic and phenotypic studies in the lab, greenhouse, and field. Project results will be interpreted in terms of their implications for the evolution, mitigation, and management of weed populations and the prevention or reduction of weed spread. Results and their management implications will be communicated to CE specialists, farm advisors, growers, land managers, pest control advisors, and the general public.
Animal Health Component
(N/A)
Research Effort Categories
Basic
100%
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
21324201140100%
Knowledge Area
213 - Weeds Affecting Plants;

Subject Of Investigation
2420 - Noncrop plant research;

Field Of Science
1140 - Weed science;
Goals / Objectives
To investigate the evolutionary, genetic, and demographic processes underlying the introduction, establishment, and spread of agricultural and invasive weeds in California for the purposes of informing the design of effective, long-term weed management programs.
Project Methods
Multiple approaches will be used to conduct the project, including field surveys, population-level sampling, population genetic and/or population genomic (depending on available funding) analyses, and genetic and phenotypic studies in the lab, greenhouse, and field. Results will be analyzed using standard weed science, population genetic/genomic, ecological, and evolutionary statistical approaches. Dose response analyses will be used to evaluate herbicide resistance phenotypes and levels in weed populations. Project results will be interpreted in terms of their implications for the evolution, mitigation, and management of weed populations and the prevention or reduction of weed spread. Results and their management implications will be communicated to CE specialists, farm advisors, growers, land managers, PCAs, and the general public.

Progress 12/11/13 to 09/30/18

Outputs
Target Audience:Pest control advisors (PCAs), farm advisors, Master Gardeners, farmers, herbicide company personnel, CE specialists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Four undergraduate students, one Masters student, one PhD student, and three postdoctoral fellows were mentored and trained in scientific principles, questions, approaches, methods, and analyses used in weed science. The latter included field sampling, growing plants in greenhouses and growth cabinets for scientific study, testing plant response to herbicides (including dose-response studies), DNA sequencing, data analyses, writing scientific papers, and making outreach presentations. How have the results been disseminated to communities of interest?The results have been disseminated to multiple communities of interest, including Pest Control Advisors (PCAs), growers, farm advisors, Master Gardeners, CE specialists, and herbicide company personnel. The presentations include the following: (1) Presentation at ANR Pest Management Program Team meeting titled "Origins, evolution, and management of invasive and herbicide-resistant weeds" on 6-15-2016 at Davis, CA (2) Presentation at 60th Annual Weed Day meeting titled "Changes in herbicide resistance in Italian ryegrass populations over the last 10 years and their underlying causes" on 7-7-2016 at Davis, CA (3) Presentation at Master Gardeners meeting titled "Weeds, herbicide resistance, and horticultural invasives" on 9-22-2016 at Placerville, CA (4) Presentation at Stanislaus Farm Supply agronomy seminar titled "Multiple herbicide resistance in California Italian ryegrass", 1-26-2PAPA california017 at Modesto, CA (5) Presentation at Weed Science School, UC Weed Research and Information Center, titled "Understanding molecular genetics - a key for weed management decisions" on 8-24-2017 at Davis, CA (6) Presentation at 62nd Annual Weed Day meeting titled "Effect of elevated CO2 levels and increased temperatures on glyphosate efficacy", 7-12-2018. (7) UC Weed Science blog article titled "Multiple independent origins of glyphosate resistance in Italian ryegrass", 3-5-2018. (8) Presentation to the Pesticide Applicators Professional Association (PAPA) titled "Herbicide resistance across California", 9-26-2018, Sacramento, CA. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Changes in Knowledge: (1) New knowledge on the evolution, spread (geographic distribution), levels, genetic bases, and underlying mechanisms of resistance to glyphosate, glufosinate, paraquat, ACCase-inhibiting, and ALS-inhibiting herbicides in Italian ryegrass within perennial and annual crops of the Central Valley, California. (2) New knowledge on the evolution, spread (geographic distribution), levels, genetic basis, and underlying mechanisms of multiple herbicide-resistant Italian ryegrass in California. (3) New knowledge on the herbicides that control herbicide-resistant and multiple-herbicide-resistant Italian ryegrass in California. (4) New knowledge confirming the spread of herbicide resistance in Italian ryegrass through gene flow. (5) New knowledge on the need for resistance management practices that limit seed and pollen dispersal in Italian ryegrass. (6) New knowledge on the reduced sensitivity of weeds to glyphosate under conditions of increased temperatures and elevated CO2 levels as predicted under changing climatic conditions in California.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Ravet, K., E.L. Patterson, H. Krahmer, K. Hamouzova, L. Fan, M. Jasieniuk, A. Lawton-Rauh, J.M. Malone, J.S. McElroy, A. Merotto Jr., P. Westra, C. Preston, M.M. Vila-Aiub, R. Busi, P.J. Tranel, C. Reinhardt, C. Saski, R. Beffa, P. Neve, and T. Gaines. 2018. The power and potential of genomics in weed biology and management. Pest Management Science 74:2216-2225.
  • Type: Journal Articles Status: Under Review Year Published: 2018 Citation: Tehranchian, P., V.K. Nandula, M. Matzrafi, and M. Jasieniuk. Multiple herbicide resistance in California Italian ryegrass (Lolium multiflorum ssp. multiflorum): Characterization of ALS-inhibiting herbicide resistance. Weed Science, In review
  • Type: Journal Articles Status: Under Review Year Published: 2018 Citation: Matzrafi, M., C. Brunharo, P. Tehranchian, B.D. Hanson, and M. Jasieniuk. Increased temperatures and elevated CO2 levels reduce the sensitivity of Conyza canadensis and Chenopodium album to glyphosate. Scientific Reports, In review.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: P. Tehranchian, R. Beffa, and M. Jasieniuk. 2018. Confirmation, characterization and control of glufosinate-resistant Italian ryegrass in California. Proceedings of the Weed Science Society of America Annual Meeting, January 29-February 1, Arlington, VA
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: P. Tehranchian, V. Nandula, C. Fautt, and M. Jasieniuk. 2018. Characterization of ALS-inhibiting herbicide resistance in California multiple resistant Italian ryegrass populations. Proceedings of the Weed Science Society of America Annual Meeting, January 29-February 1, Arlington, VA
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: M. Matzrafi, C. Fautt, and M. Jasieniuk. 2018. Effect of elevated CO2 levels and increased temperatures on glyphosate efficacy. Proceedings of the Weed Science Society of America Annual Meeting, January 29-February 1, Arlington, VA
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: P. Tehranchian, I.M. Heap, T. Deveaud, M. Matzrafi, and M. Jasieniuk. 2018. Distribution and frequency of herbicide resistant Italian ryegrass populations in the Central Valley of California. Proceedings of the Weed Science Society of America Annual Meeting, January 29-February 1, Arlington, VA
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: P. Tehranchian, V. Nandula, M. Jugulam, and M. Jasieniuk. 2018. Multiple resistance to glyphosate, paraquat, ACCase- and ALS-inhibitors in California Italian ryegrass: confirmation, control and resistance mechanisms. Proceedings of the Weed Science Society of America Annual Meeting, January 29-February 1, Arlington, VA
  • Type: Other Status: Published Year Published: 2018 Citation: M. Matzrafi and M. Jasieniuk. Effect of elevated CO2 levels and increased temperatures on glyphosate efficacy. Page 19 in 62nd Annual Weed Day Booklet, UC Davis Weed Science Program and UC Weed Research and Information Center, University of California, Davis


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

Outputs
Target Audience:Growers, farm advisors, Pest Control Advisors (PCAs), herbicide company personnel, CE specialists, weed scientists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Two undergraduate students, one PhD student, and two postdoctoral fellows were mentored and trained in scientific principles, approaches, and methods used in weed science, including field sampling, growing plants in the greenhouse for scientific study, testing plant response to herbicides (including dose-response studies), DNA sequencing, data analyses, writing scientific papers, and making outreach presentations. How have the results been disseminated to communities of interest?(1) Presentation to Cooperative Extension, herbicide company personnel, and weed scientists at the Weed Science Society of America Annual Meeting in Tucson, AZ, February 6-9, 2017 on the confirmation and characterization of glufosinate-resistant Italian ryegrass in a California grain field. (2) Presentation to Cooperative Extension, herbicide company personnel, and weed scientists at the Weed Science Society of America Annual Meeting in Tucson, AZ, February 6-9, 2017 on multiple herbicide resistance in Italian ryegrass from California orchards and roadsides. What do you plan to do during the next reporting period to accomplish the goals?(1) Continue to characterize the evolution, genetic basis, and mechanisms underlying glufosinate resistance in Italian ryegrass in perennial and annual crops of California. (2) Investigate changes in herbicide resistance Italian ryegrass over a decade of weed management in perennial and annual crops of California. (3) Continue to associate crop and weed management practices in California orchards, vineyards, crop fields, and roadsides to the presence/absence of Italian ryegrass and to the frequency of herbicide-resistant ryegrass plants and the levels of resistance to the various herbicides to identify those practices that are most highly correlated with low weed abundance and resistance. (4) Begin to investigate the role of changing climatic and environmental conditions on the evolution and spread of weeds in California agriculture, the efficacy of different weed control practices, and weed species changes in perennial and annual crops.

Impacts
What was accomplished under these goals? Changes in Knowledge: (1) New knowledge on the evolution and degree of multiple resistance to glyphosate, paraquat and ACCase-inhibiting herbicides in Italian ryegrass in perennial and annual crops of the Central Valley, California. (2) New knowledge of the genetic basis and molecular and physiological mechanisms underlying resistance to glyphosate, paraquat, and ACCase-inhibiting herbicides in California Italian ryegrass. (3) New knowledge of the herbicides that control multiple herbicide-resistant Italian ryegrass in California agriculture. (4) New knowledge of the evolutionary and geographic origins of glyphosate-resistant Italian ryegrass in California orchards and vineyards. (5) New knowledge confirming the spread of herbicide resistance in Italian ryegrass through gene flow. (6) New knowledge on the need for resistance management practices that limit seed and pollen dispersal in Italian ryegrass.

Publications

  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Tehranchian, P., V. Nandula, M. Jugulam, K. Putta, and M. Jasieniuk. 2017. Multiple resistance to glyphosate, paraquat and ACCase-inhibiting herbicides in Italian ryegrass populations from California: confirmation and mechanisms of resistance. Pest Management Science (2017) DOI: 10.1002/ps.4774
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Karn, E. and M. Jasieniuk. 2017. Nucleotide diversity at site 106 of EPSPS in Lolium perenne L. ssp. multiflorum from California indicates multiple evolutionary origins of herbicide resistance. Frontiers in Plant Science 8(2017): Article 777. DOI: 10.3389/fpls.2017.00777
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Karn, E. and M. Jasieniuk. 2017. Genetic diversity and structure of Lolium perenne ssp. multiflorum in California vineyards and orchards indicate potential for spread of herbicide resistance via gene flow. Evolutionary Applications 10(2017):616-629. DOI: 10.1111/eva.12478
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Karn, E., R. Beffa, and M. Jasieniuk. 2017. Variation in response and resistance to glyphosate and glufosinate in Italian ryegrass. Weed Science DOI: 10.1017/wsc.2017.71 *
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Tehranchian, P., I.M. Heap, and M. Jasieniuk. 2017. Confirmation and characterization of a glufosinateresistant Italian ryegrass population from a California grain field. Weed Science Society of America annual meeting, Tucson, AZ, February 6-9, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Tehranchian, P., I.M. Heap, and M. Jasieniuk. 2017. Investigations of multiple herbicide resistance in Italian ryegrass populations from orchards and roadsides in California. Weed Science Society of America Annual Meeting, Tucson, AZ, February 6-9, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Tehranchian, P., T. Deveaud, I.M. Heap, and M. Jasieniuk. 2017. Evidence for multiple herbicide-resistant Lolium multiflorum populations in northern California. Global Herbicide Resistance Challenge 2017, Denver, CO, May 14-18, 2017.
  • Type: Theses/Dissertations Status: Published Year Published: 2016 Citation: Karn, Elizabeth (Major Professor = M. Jasieniuk). 2016. Evolution of herbicide resistance in Lolium perenne) ssp. multiflorum populations. PhD dissertation in Plant Biology, University of California-Davis, Davis, CA.
  • Type: Other Status: Other Year Published: 2016 Citation: M. Jasieniuk. 2016. Managing the evolution of weed adaptations: is it possible? Staniforth Lecture, Iowa State University, Ames, IA, October 25, 2016.


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

Outputs
Target Audience:Farmers, Master Gardeners, farm advisors, Pest Control Advisors (PCAs), County Ag Commissioners, CE specialists, weed scientists, herbicide company (Bayer CropScience) personnel, undergraduate and graduate students Changes/Problems:For Objective 2: (1) We increased the geographic extent of the research. We are studying Italian ryegrass across the Central Valley in addition to "northwest California" as originally proposed. We were awarded a USDA-NIFA-AFRI grant that allows us to substantially increase the geographic area studied. (2) Our studies indicate that Italian ryegrass from specific areas are resistant to sethoxydim and paraquat, in addition to glyphosate and glufosinate. Thus, we are studying resistance to all four herbicides. What opportunities for training and professional development has the project provided?Six undergraduate students, two PhD students, one postdoctoral fellow, and one Junior Specialist were mentored and trained in scientific principles, approaches, and methods used in agricultural research, including field sampling, growing plants in the greenhouse for scientific study, testing plant response to herbicides, assessment of weed resistance to herbicides, DNA sequencing, genotyping using microsatellite markers, and population genetic analyses. How have the results been disseminated to communities of interest?(1) Presentation at Master Gardeners meeting titled "Weeds, herbicide resistance, and horticultural invasives" on 9-22-2016 at Placerville, CA (2) Presentation at 60th Annual Weed Day meeting titled "Changes in herbicide resistance in Italian ryegrass populations over the last 10 years and their underlying causes" on 7-7-2016 at Davis, CA (3) Presentation at ANR Pest Management Program Team meeting titled "Origins, evolution, and management of invasive and herbicide-resistant weeds" on 6-15-2016 at Davis, CA (4) Presentation to UC Davis student Food Tech Club on agricultural weeds and herbicide resistance on 5-17-2016 at Davis, CA (5) Presentation titled "Inferring the evolution and spread of agricultural weeds and invasive plants using molecular tools" in the Graduate Student Organized Symposium at the North Central Weed Science Society meeting in Indianapolis, IN on 12-9-2015 (6) Presentation, with PhD student, at the Western Society of Weed Science titled "Spatial genetic structure and glyphosate resistance in Lolium perenne ssp. multiflorum (Italian ryegrass) in California orchards and vineyards" on 3-9-2016 at Albuquerque, NM What do you plan to do during the next reporting period to accomplish the goals?(1) Continue to characterize glyphosate, glufosinate, sethoxydim, and paraquat resistance in Italian ryegrass from agricultural areas in California. (2) Correlate crop and weed management practices in California orchards, vineyards, crop fields, and roadsides to the presence/absence of Italian ryegrass and to the frequency of herbicide-resistant ryegrass plants and the levels of resistance to the various herbicides. (3) Continue to investigate the genetic bases of resistance and the molecular and physiological mechanisms underlying resistance to glyphosate, glufosinate, sethoxydim, and paraquat in ryegrass. (4) In combination, use the data form the resistance testing of Italian ryegrass from the 108 agricultural areas, the herbicide use histories for each area, and the farmer and land owner interviews to develop herbicide resistance management approaches for Italian ryegrass in California. (5) Continue to examine the evolution and spread of resistance to herbicides in agricultural weeds of California.

Impacts
What was accomplished under these goals? Changes in Knowledge: (1) New knowledge of the geographic distribution of herbicide-resistant Italian ryegrass in orchards, vineyards, crop fields, and roadsides across the Central Valley of California. (2) New knowledge of the changes in the percentage of glyphosate-resistant plants over the last 10 years (2005-2015) in Italian ryegrass populations across the Central Valley of California. (3) New knowledge of the geographic distribution of Italian ryegrass populations resistant to multiple herbicides (glyphosate, sethoxydim, and paraquat) across the Central Valley of California. (4) New knowledge of the geographic distribution of glufosinate-resistant Italian ryegrass across the Central Valley of California. (5) New knowledge of herbicide use (types, quantities, and frequencies of application) histories and patterns in agricultural areas of the Central Valley. (6) New knowledge of the genetic basis of resistance to glyphosate in ryegrass from northwest California. (7) Preliminary new knowledge of the genetic and physiological mechanisms underlying resistance to glyphosate, sethoxydim, paraquat, and glufosinate in ryegrass from agricultural areas in California.

Publications

  • Type: Journal Articles Status: Submitted Year Published: 2017 Citation: Karn, E. and M. Jasieniuk. Genetic diversity and structure of Lolium perenne ssp. multiflorum in California vineyards and orchards indicates potential for spread of herbicide resistance via gene flow. Evolutionary Applications, Submitted
  • Type: Journal Articles Status: Submitted Year Published: 2017 Citation: Karn, E., R. Beffa, and M. Jasieniuk. Variation in response and resistance to glyphosate and glufosinate in Italian ryegrass. Weed Science, Submitted
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Shrestha,A., K.M. Steinhauer, B.D. Hanson, M. Jasieniuk, K.J. Hembree, and S.D. Wright. 2016. Growth and development of fall- and spring-planted populations of Conyza canadensis and C. bonariensis. International Journal of Pest Management 62:300-307.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Moretti, M.L., L.M. Sosnoskie, A. Shrestha, S.D. Wright, K.J. Hembree, M. Jasieniuk, B.D. Hanson. 2016. Distribution of Conyza sp. in orchard and vineyards of California and response to glyphosate and paraquat. Weed Science 64:339-347.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Karn, E. and M. Jasieniuk. 2016. Spatial genetic structure and glyphosate resistance in Lolium perenne ssp. multiflorum (Italian ryegrass) in California orchards and vineyards. Western Society of Weed Science annual meeting, Albuquerque, NM, March 7-10, 2016
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Jasieniuk, M. 2015. Inferring the evolution and spread of agricultural weeds and invasive plants using molecular tools, Invited presentation in Graduate Student organized symposium, North Central Weed Science Society annual meeting, Indianapolis, IN, December 7-10, 2015


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

Outputs
Target Audience:Farm advisors, CE specialists, PCAs (Pest Control Advisors), weed scientists, herbicide company personnel Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Two PhD students, four undergraduate students, and one Junior Specialist were mentored and trained in scientific principles, approaches, and methods used in agricultural research, in particular, field sampling, testing plant response to herbicides, and assessment of weed resistance to herbicides. How have the results been disseminated to communities of interest?Data and results obtained during this reporting period are too preliminary to be disseminated too widely since conclusions may change as data continues to be collected. However, I have communicated some of the research results to growers, farm advisors, CE specialists, Pest Control Advisors and scientists during field sampling trips, Weed Day, Weed Workgroup meeting, Weed Science Society of America annual meeting, and communications with Bayer CropScience scientists. Bayer CropScience is the manufacturer of glufosinate. What do you plan to do during the next reporting period to accomplish the goals?(1) Complete testing 108 ryegrass populations across northern California for plant response and resistance to glyphosate, glufosinate, sethoxydim, and paraquat. (2) Complete dose-response experiments to determine resistance levels in a subset of populations. (3) Complete collection of herbicide use data for the last 10 years from the DPR (Department of Pesticide Regulation) pesticide use database. (4) Complete interviewing growers and land managers for information on the herbicide and non-herbicide weed management practices used in each of the 108 areas sampled for ryegrass. (5) Submit grant proposals for research funding to examine the underlying genetic and evolutionary causes of the differences in expression and geographical distribution of glyphosate resistance between Conyza canadensis and C. bonariensis in the Central Valley of California. (6) Continue to submit grant proposals for research funding to examine how habitat fragmentation in natural, urban, and managed systems influences the connectedness and evolution of native, naturalized and invasive plant populations, and the spread of invasive plants/weeds in these lands.

Impacts
What was accomplished under these goals? We continue to characterize resistance to both glyphosate and glufosinate in Italian ryegrass across northern California. Our studies showed that plant response to the two herbicides is influenced by environmental conditions such that the resistance phenotype is expressed to varying degrees depending on the season and conditions at herbicide application. This result has large implications for growers since approaches used to successfully manage herbicide-resistant weeds may need to differ with the environment. In addition, seeds were collected from an additional 108 ryegrass populations across northern California and are currently being tested for resistance to four herbicides commonly used in California orchards and vineyards to determine the range of spread of resistance.

Publications

  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Okada, M., B.D. Hanson, K.J. Hembree, Y. Peng, A. Shrestha, C.N. Stewart Jr., S.D. Wright, and M. Jasieniuk. 2015. Evolution and spread of glyphosate resistance in Conyza bonariensis in California and a comparison with closely related Conyza canadensis. Weed Research 55:173 -184.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Peng, Y., Z. Lai, T. Lane, M. Nageswara-Rao, M. Okada, M. Jasieniuk, H. O'Geen, R.W. Kim, R. D. Sammons, L.H. Rieseberg and C.N. Stewart, Jr. De novo genome assembly of the economically important weed horseweed using integrated data from multiple sequencing platforms. Plant Physiology 166:1241-1254.
  • Type: Other Status: Published Year Published: 2015 Citation: Karn, E. and M. Jasieniuk. Resistance and variation in the response of Lolium multiflorum to glyphosate and glufosinate. 59th Annual Weed Day Booklet, Weed Science Program, Weed Research and Information Center, University of California, Davis.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: E. Karn and M. Jasieniuk. 2015. Glufosinate- and glyphosate-resistant Italian ryegrass (Lolium multiflorum) in California orchards and vineyards. Weed Science Society of America Annual Meeting, February 9-12, Lexington, KY.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Hanson, B.D., S. Wright, L.M. Sosnoskie, A.J. Fischer, M. Jasieniuk, J.A. Roncoroni, K.J. Hembree, S. Orloff, A. Shrestha and K. Al-Khatib. 2014. Herbicide-resistant weeds challenge some signature cropping systems. California Agriculture 68:142-152.
  • Type: Book Chapters Status: Published Year Published: 2014 Citation: Hanson, B.D., A.J. Fischer, A. McHughen, M. Jasieniuk, A. Shrestha, and A.J. Jhala. 2014. Herbicide-resistant weeds and crops. In S. Fennimore and S. Bell (eds.), Principles of Weed Science - 4th edition, California Weed Science Society, California, USA


Progress 12/11/13 to 09/30/14

Outputs
Target Audience: Farm advisors, CE specialists, university weed scientists, herbicide company scientists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? One PhD student and three undergraduate students are being trained in the methods used to assess weeds for resistance to herbicides and to determine the origins and pathways of spread of agricultural weeds and invasive plants. How have the results been disseminated to communities of interest? I included aspects of the research on the evolution and spread of weed adaptations to management practices in all courses that I teach to make students aware of the difficulties involved in managing pests over the long-term. In addition, my PhD student and I have communicated some of the research results to growers, farm advisors, CE specialists, Pest Control advisors and scientists during field sampling trips, Weed Day, the Weed Science Society of America annual meeting, and communications with Bayer CropScience scientists. Bayer CropScience is the manufacturer of glufosinate. What do you plan to do during the next reporting period to accomplish the goals? Continue research on plant response to glyphosate and glufosinate, establish the levels of resistance by conducting dose-response experiments, complete genotyping of plants to assess the origins and spread pathways of resistance, test for the presence of resistance mutations, confirm a genetic basis to the resistance.

Impacts
What was accomplished under these goals? We confirmed resistance to both glyphosate and glufosinate in Italian ryegrass from orchards and vineyards in northwestern California during the review period. We also showed that the two types of resistance evolved independently since some plants within a population were resistant to glyphosate, some to glufosinate, and some to both thus resistance to both herbicides was not tightly linked. Our studies also showed that plant response to the two herbicides is influenced by environmental conditions such that the resistance phenotype is expressed to a varying degree depending on the season and conditions at herbicide application. We are currently conducting further studies to quantify this environmental effect on the expression of resistance. This result has large implications for growers since the approaches used to successfully manage herbicide-resistant weeds may need to differ with the environment.

Publications

  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Shrestha, A, KM Steinhauer, ML Moretti, BD Hanson, M Jasieniuk, KJ Hembree, SD Wright. 2014. Distribution of glyphosate-resistant and glyphosate-susceptible hairy fleabane (Conyza bonariensis) in central California and their phenological development. Journal of Pest Science 87:201-209
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Konduru, S, M Jasieniuk, BD Hanson, K Hembree, SD Wright, A Shrestha. 2014. Cost analysis of alternative treatments for managing glyphosate-resistant Conyza spp. in orchards and vineyards. Weed Science Society of America 54th Annual Meeting, Feb 3-6, Vancouver, BC.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Jasieniuk M, A Kleist, A Herrera-Reddy, R Sforza. 2014. Inferring the complex origins of horticultural invasives: French broom in California. Weed Science Society of America 54th Annual Meeting, Feb 3-6, Vancouver, BC
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Jasieniuk M, M Okada, BD Hanson, K Hembree, Y Peng, A Shrestha, N Stewart, SD Wright. 2014. Evolution and spread of glyposate resistance in Conyza canadensis and C. bonariensis in California orchards and vineyards. Weed Science Society of America 54th Annual Meeting, Feb 3-6, Vancouver,BC.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Kleist, A, AM Herrera-Reddy, R Sforza, M Jasieniuk. 2014. Inferring the complex origins of horticultural invasives: French broom in California. Biological Invasions 16:887-901
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Okada, M and M Jasieniuk. 2014. Inheritance of glyphosate resistance in hairy fleabane (Conyza bonariensis) from California. Weed Science 62:258-266
  • Type: Other Status: Published Year Published: 2013 Citation: Hanson, B, A Fischer, A Shrestha, M Jasieniuk, E Peachey, R Boydston, T Miller, K Al-Khatib. 2013. Selection pressure, shifting populations, and herbicide resistance and tolerance. University of California, Division of Agriculture and Natural Resources, ANR Publication 8493. 6 pg.
  • Type: Other Status: Published Year Published: 2014 Citation: Karn, EV and M Jasieniuk. 2014. Glyphosate and glufosinate resistance in Italian ryegrass in Sonoma and Lake County. 58th Annual Weed Day, July 10, 2014