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Agricultural Research Center – Hays

Weed Science


Kumar in Soybean Field looking at Kochia
Vipan Kumar, Assistant Professor of Weed Science


In the News


Studies show as much as five-fold resistant shattercane in northwest Kansas
May 3, 2021
HAYS, Kan. – Kansas State University researchers are reporting that shattercane, a grass weed found in grain sorghum fields, is showing resistance to herbicides designed to stem its growth.

Vipan Kumar, a weed scientist at the K-State Agricultural Research Center in Hays, said the findings are particularly important as producers decide on whether to plant three new grain sorghum hybrids this summer.  Continue Reading...

Vipan Kumar, named Outstanding Young Scientist
Dec. 11, 2020
HAYS, Kan. – Vipan Kumar, a weed science researcher at the Kansas State University Agricultural Research Center whose work has helped boost dryland cropping systems in the Great Plains region has received an early career award from the North Central Weed Science Society. Read more...

K-State Radio program discussing different herbicide programs in wheat stubble
Date: July 1, 2020
K-State weed scientist Vipan Kumar goes over the results of his herbicide field trial, which tested out a number of products for their effectiveness in controlling Palmer amaranth in post-harvest wheat stubble...he also tells of a new survey of Kansas crop producers and crop consultants he's conducting on the prevalent crop weed issues in the state.  Listen to Podcast

New study evaluated different herbicide programs in wheat stubble
Date: July 1, 2020
Recent rainfall events across various parts of Kansas have slowed down the wheat harvest, but wet soil and high temperatures have provided a conducive environment for Palmer amaranth seedbanks to germinate in standing wheat. In fact, several wheat fields with poor canopy closure have been observed with severe infestation of Palmer amaranth populations

Kansas weed survey: Producers/ag professionals input requested
Date: July 1st, 2020
Herbicide-resistant weeds are threatening the profitability and long-term sustainability of Kansas cropping systems. To help develop innovative, cost-effective, and integrated weed management practices for controlling herbicide-resistant weeds and to further improve the outreach programs for various regions of the state, the Weed Science group at the K-State Ag Research Center in Hays seeks input from Kansas producers and ag professionals (crop consultants, county agents, certified crop advisors). We invite you to please complete a brief survey related to weed management practices and herbicide-resistant weed problems. The survey will take 5-8 minutes and can be completed via this weblink: Kansas Weeds Survey  

K-State scientist earns early career award for fighting weeds
March, 19, 2020
HAYS, Kan. – Vipan Kumar, an assistant professor of weed science at the Kansas State University Agricultural Research Center in Hays, received one of the top awards for young professionals during a joint meeting of the Weed Science Society of America and Western Society of Weed Science. 

Weed Management Field Day - Press Release
Jun 11, 2019
HAYS, Kan. – The K-State Research and Extension Agricultural Research Center in Hays will host its annual weed management field day on Tuesday, July 2.  The event will include discussions and demonstrations related to weed control in corn, soybeans, grain sorghum and sunflower. It will run from 8 a.m. to 1:30 p.m.  Vipan Kumar, a weed scientist at the research center, said the field day includes demonstrations of herbicide tools for weed control in corn, and an herbicide drift simulation on soybeans.  

K-State Researcher Confirm Palmer Amaranth Resistance to 2,4-D
Friday, March 8, 2019
Vipan Kumar, a weed scientist at the Agricultural Research Center in Hays, is reporting the first-ever study confirming that Palmer amaranth has developed resistance to the herbicide 2,4-D.  Kumar’s findings have been published in the journal, Pest Management Science. The article, titled “Confirmation of 2,4‐D resistance and identification of multiple resistance in a Kansas Palmer amaranth (Amaranthus palmeri) population.  Read the full press release.

A Review Article on Herbicide-Resistant Kochia featured by Weed Science Society of America
"A review article on herbicide-resistant kochia in North America” compiled by weed researchers from Kansas State and Montana State University has been selected as a featured article in Weed Science journal published by the Weed Science Society of America. This article has compiled information from several published studies and articles relevant to herbicide-resistant kochia, its impact and control strategies. Want to know more on this article, please read it on the Weed Science of America website.    

Multiple Herbicide Resistant Palmer Amaranth in Kansas
Tuesday, January 29, 2019
Ongoing herbicide resistant Palmer Amaranth research, under the direction of Vipan Kumar, at the KSU Agricultural Research Center - Hays is featured in the recent article on the Progressive Farmer website.

Auxinic-Resistant Kochia found in Kansas
Thursday, October 11, 2018
The weed science research team at Kansas State University, under the direction of Vipan Kumar, identified Kochia biotypes that have developed cross resistance to dicamba and fluroxypyr herbicides in western Kansas.  These biotypes have also been found resistant to glyphosate.  To learn more about this research, continue reading on the Progressive Farmer website.

Research Interests

My research interests fall within an area of weed biology, ecology and its management. The primary goal of my research program is to evaluate and develop integrated weed management strategies for irrigated and dry land cropping systems in western Kansas. In recent years, the widespread evolution of herbicide-resistant (HR) weeds (mainly kochia, Palmer amaranth, and horseweed) has threatened the profitability and long-term sustainability of no-till dry land crop production in this region. To achieve the overall goal, my program relies on basic and applied weed science research. Some specific research priorities are listed below:

  • Monitoring the occurrence, spread and characterization of new cases of herbicide-resistant weeds in Kansas cropping systems. This is an important aspect of my research program
  • Environmental and management factors on germination, emergence and growth behavior of Palmer amaranth, kochia and horseweed populations in U.S. Central Great Plains
  • Evaluate new and existing herbicide chemistries for use in rotation or tank-mixtures for crop safety and control of herbicide-resistant and susceptible weeds in wheat, corn, soybean, sorghum, sunflower, and fallow fields
  • Evaluate newly developed/commercialized herbicide-resistant crop technologies (such as Roundup Ready 2 Xtend® soybeans, CoAXium™ Wheat Production, Inzen™ sorghum) for weed control
  • Off-target injury risk assessment from newly developed herbicide-resistant crops through simulation drift studies
  • Integration of chemical, mechanical (tillage) and cultural practices (crop rotation, seeding rates, row spacing, cover crops) for sustainable weed management in no till dry land production systems of western Kansas   


  • Weed biology and management


  • 2020 - Outstanding Weed Scientist - Early Carrier (Public Sector), Western Society of Weed Science.
  • 2020 - Outstanding Reviewer Award, Weed Science Journal, Weed Science Society of America
  • 2014 - Elena Sanchez Memorial Outstanding Ph.D. Graduate Student Award, Western Society of Weed Science.

Societies Affiliation

  • Weed Science Society of America
  • Western Society of Weed Science
  • North Central Weed Science Society
  • American Society of Agronomy

Professional Activities

  • Associate Editor for Weed Science Journal, Weed Science Society of America
  • Associate Editor for Weed Technology Journal, Weed Science Society of America
  • Associate Editor for Agronomy Journal, American Society of Agronomy
  • Reviewer for Weed Science, Weed Technology, Crop Protection, Pest Management Science, PLoS ONE, Agronomy Journal, Canadian Journal of Plant Science, Journal of Environmental Management, Crop, Forage, and Turfgrass Management, International Journal of Pest Management, and Science of the Total Environment    

Peer Reviewed Publications

  • Kumar V., A. Obour, P. Jha, R. Liu, M. Manuchehri, J.A. Dille, J. Holman, and P.W. Stahlman. (2020)  Integrating Cover Crops for Weed Management in the Semi-Arid U.S. Great Plains: Opportunities and Challenges. Weed Science. DOI: https://doi.org/10.1017/wsc.2020.29

  • Yadav R., V. Kumar, P. Jha. (2020)  Herbicide Programs to Manage Glyphosate-Resistant and Dicamba-Resistant Kochia (Bassia scoparia) in Glyphosate plus Dicamba-Resistant Soybean. Weed Technology. DOI: https://doi.org/10.1017/wet.2020.3

  • Kumar V., R. Liu, P.W. Stahlman. (2020)  Differential Sensitivity of Kansas Palmer Amaranth to Glyphosate, Chlorsulfuron, 2,4-D, Dicamba, Atrazine, and Mesotrione.  Agronomy Journal. https://doi.org/10.1002/agj2.20178 

  • Lyon D.J., M.E. Thorne, P. Jha, V. Kumar, T.M. Waters. (2019)  Volunteer Buckwheat Control in Wheat. Crop, Forage, and Turfgrass Management. DOI:  10.2134/cftm2019.05.0033

  • Kumar V., R. Liu, G. Boyer, P.W. Stahlman. (2019)  Confirmation of 2,4‐D Resistance and Identification of Multiple Resistance in a Kansas Palmer Amaranth (Amaranthus palmeri) Population. Pest Management Science. DOI:10.1002/ps.5400

  • Kumar V., R. Currie, P. Jha, P.W. Stahlman (2019) First Report of Kochia (Bassia scoparia) with Cross-Resistance to Dicamba and Fluroxypyr in Western Kansas. Weed Technology.  DOI:10.1017/wet.2018.113

  • Mikha M., A. Obour, V. Kumar, P. W. Stahlman. (2018)  Soil Physicochemical Properties Influenced by Nitrogen Sources and Rates in the Central Great Plains. Journal of Soil and Water Conservation

  • Kumar V., R. P. Engel, R. Currie, P. Jha, P. Stahlman, C. Thompson (2018)  Dicamba Resistant Kochia (Bassia scoparia) in Kansas: Characterization and Management with Fallor Spring-Applied Preemergence Herbicides. Weed Technology. DOI: 10.1017/wet.2019.4

  • Kumar V., P. Jha, M. Jugulam, R. Yadav, P. W. Stahlman (2018)  Herbicide-Resistant Kochia (Bassia scoparia) in North America: A Review. Weed Science. DOI: 10.1017/wsc.2018.72 (Selected as a featured article in Weed Science journal Vol 67, Issue 1.

  • Kumar V., P. Jha, C.A. Lim, P. W. Stahlman (2018)  Differential Germination Characteristics of Dicamba-Resistant Kochia (Bassia scoparia) Populations in Response to Temperature. Weed Science. https://doi.org/10.1017/wsc.2018.54

  • Shaw J., P. Jha, P. Nugent, A. Donelick, B. Scherrer, V. Kumar (2017)  Discrimination of Herbicide-Resistant Weeds with Hyperspectral Imaging. Journal of Applied Remote Sensing. DOI:10.1117/1.JRS.12.016037

  • Ganie Z.A., S. Kaur, P. Jha, V. Kumar, A. J. Jhala (2017) Effect of Late-Season Herbicide Applications on Inflorescence and Seed Production of Glyphosate-Resistant Giant Ragweed (Ambrosia trifida L.). Weed Technology. https://doi.org/10.1017/wet.2017.101

  • Jha P., V. Kumar, C. A. Lim, R. Yadav (2017) Evaluation of Preemergence Herbicides for Crop Safety and Weed Control in Safflower. American Journal of Plant Sciences. DOI:10.4236/ajps.2017.810158

  • Kumar V., P. Jha., A. J. Jhala (2017) Using Pyroxasulfone for Downy Brome (Bromus tectorum L.) Control in Winter Wheat. American Journal of Plant Sciences. DOI:10.4236/ajps.2017.810159

  • Kumar V., J. Felix, D. Morishita, P. Jha (2017) Confirmation of Glyphosate-Resistant Kochia (Kochia scoparia L.) from Sugar Beet Fields in Idaho and Oregon. Weed Technology. DOI: 10.1017/wet.2017.80

  • Kumar V., P. Jha, J. A. Dille, P. W. Stahlman (2017) Emergence Dynamics of Kochia (Kochia scoparia) Populations from the US Great Plains: A Multi-Site-Year Study. Weed Science. https://doi.org/10.1017/wsc.2017.55

  • Kumar V., P. Jha (2017) First Report of Ser653Asn Mutation Endowing High-level Resistance to Imazamox in Downy brome (Bromus tectorum L.). Pest Management Science. http://onlinelibrary.wiley.com/doi/10.1002/ps.4673/full

  • Jha P., V. Kumar (2017) Pulse Crop Tolerance and Weed Control with Fall-Applied SoilResidual Herbicides. Agronomy Journal. Doi:10.2134/agronj2017.06.0320

  • Kumar V., P. Jha, A. Jhala (2017) Confirmation of Glyphosate-Resistant Horseweed (Conyza canadensis L.) in Montana Cereal Production and Response to Postemergence Herbicides. Weed Technology. https://doi.org/10.1017/wet.2017.49

  • Kumar V., P. Jha., J. F. Spring, D. J. Lyon, I. C. Burke (2017) Glyphosate-Resistant Russian thistle (Salsola tragus L.) Identified in Montana and Washington. Weed Technology. https://doi.org/10.1017/wet.2016.32

  • Kumar V., P. Jha (2017) Effect of Temperature on Germination Characteristics of Glyphosate-Resistant and -Susceptible Kochia scoparia. Weed Science.  https://doi.org/10.1017/wsc.2016.26

  • Gaines T. A., A. L. Barker, E. L. Patterson, P. Westra, E. P. Westra, R. G. Wilson, P. Jha, V. Kumar, A. R. Kniss. (2016)  EPSPS Gene Copy Number and Whole-Plant Glyphosate Resistance Level in Kochia scoparia. PLoS One.  http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0168295.

  • Kumar V., P. Jha. (2016)  Differences in Germination, Growth, and Fecundity Characteristics of Dicamba-Fluroxypyr-Resistant and -Susceptible Kochia scoparia. PLoS One.  http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0161533

  • Kumar V., P. Jha. (2016)  Influence of Nitrogen Rate, Seeding Rate, and Weed Removal Timing on Weed Interference in Barley and Effect of Nitrogen on Weed Response to Herbicides. Weed Science. DOI: http://dx.doi.org/10.1614/WS-D-16-00047.1

  • Jha P., V. Kumar, R. K. Godara, B.S. Chauhan. (2016)  Weed management using crop competition in the United States. Crop Protection.  Doi:10.1016/j.cropro.2016.06.021

  • Jha P., V. Kumar, C. A. Lim. (2016)  Herbicide Resistance in Cereal Production Systems of US Great Plains: A Review. Indian Journal of Weed Science. 48 (2):1–5.http://dx.doi.org/10.5958/0974-8164.2016.00030.7

  • Udeigwe T. K., J. M. Teboh, P. N. Eze, M. H. Stietiya, V. Kumar, J. Hendrix, H. J. Mascagni (Jr), T. Ying, T. Kandakji. (2015)  Implications of Leading Crop Production Practices on Environmental Quality and Human Health. Journal of Environmental Management. 151: 267-279. DOI:10.1016/j.jenvman.2014.11.024

  • Jha P., V. Kumar. (2015)  Variable Response of Kochia [Kochia scoparia (L.) Schrad] to Auxinic Herbicides Dicamba and Fluroxypyr in Montana. Canadian Journal of Plant Science. 95 (5): 965-972. 10.4141/CJPS-2015-019

  • Jha P., J. K. Norsworthy, V. Kumar, N. Reichard. (2015)  Annual Changes in Temperature and Light Requirements for Ipomoea purpurea Seed Germination with After-Ripening in the Field following Dispersal. Crop Protection. 67:84-90. DOI:10.1016/j.cropro.2014.09.021

  • Jha P., V. Kumar, J. Garcia, N. Reichard. (2015)  Tank-Mixing Pendimethalin with Pyroxasulfone and Chloroacetamide Herbicides Enhances In-Season Residual Weed Control in Corn. Weed Technology. 29:198-206. DOI: http://dx.doi.org/10.1614/WT-D-14-00095.1

  • Kumar V., P. Jha. (2015)  Growth and Reproduction of Glyphosate-Resistant and Susceptible Populations of Kochia scoparia. PLoS One. 10(11): e0142675. DOI:10.1371/journal.pone. 0142675

  • Kumar V., T. K. Udeigwe, E. Clawson, R. Rohli, D. Miller. (2015)  Crop Water Use and Stage-specific Crop Coefficients for Irrigated Cotton in mid-South United States.  Agricultural Water Management. 15:63-69. DOI:10.1016/j.agwat.2015.03.022

  • Kumar V., P. Jha. (2015)  Influence of Glyphosate Timing on Kochia scoparia Demographics in Glyphosate-Resistant Sugar Beet. Crop Protection.76:39-45.  DOI:10.1016/j.cropro.2015.06.010

  • Kumar V., P. Jha. (2015)  Control of Volunteer Glyphosate-Resistant Canola in Glyphosate Resistant Sugar Beet. Weed Technology. 29:93-100. DOI: http://dx.doi.org/10.1614/WT-D14-00059.1

  • Kumar V., P. Jha. (2015)  Influence of Herbicides Applied Postharvest in Wheat Stubble on Control, Fecundity, and Progeny Fitness of Kochia scoparia. Crop Protection. 71:144-149.  DOI:10.1016/j.cropro.2015.02.016

  • Kumar V., P. Jha. (2015)  Effective Preemergence and Postemergence Herbicide Programs for Kochia Control. Weed Technology. 29: 24-34. DOI: http://dx.doi.org/10.1614/WT-D-14-00026.1

  • Kumar V., P. Jha, D. Giacomini, E. Westra, P. Westra. (2015)  Molecular Basis of Evolved Resistance to Glyphosate and Acetolactate Synthase-Inhibitor Herbicides in Kochia (Kochia scoparia) Accessions from Montana. Weed Science. 63: 758-769.  DOI: http://dx.doi.org/10.1614/WS-D-15-00021.1

  • Kumar V., P. Jha, N. Reichard. (2014)  Occurrence and Characterization of Kochia (Kochia scoparia) Accessions with Resistance to Glyphosate in Montana. Weed Technology. 28:122- 130. DOI: http://dx.doi.org/10.1614/WT-D-13-00115.1 (A photograph from this study was selected by the editorial board and it was published on a cover page of Weed Technology volume 29, issue 1, 2015). 

Extension Publications

  • Kumar V., R. Liu, T. Lambert (2020) Response of Kansas Feral Rye Populations to Aggressor Herbicide and Management in CoAXium Wheat Production System. Kansas Agricultural Experiment Station Research Reports.

  • Kumar V., R. Liu. (2020)  New study evaluated different herbicide programs for Palmer amaranth control in post-harvest wheat stubble. eUpdate; Issue 807: Published: June 26, 2020. https://bit.ly/2NAq1VL

  • Liu R., V. Kumar, N. Aquilina, T. Lambert (2020) Efficacy of Late-Season Herbicide Programs for Controlling Palmer Amaranth in Postharvest Wheat Stubble. Field Research Report. Kansas Agricultural Experiment Station Research Reports.

  • Liu R., V. Kumar, T. Lambert. (2020)  Control of multiple herbicide-resistant Palmer amaranth in Enlist corn. Kansas Agricultural Experiment Station Research Reports.

  • Liu R., V. Kumar, R.S. Currie, T. Lambert, P.W. Stahlman (2020) Response of Dicamba/Fluroxypyr/Glyphosate-Resistant Kochia to Atrazine and Alternative Postemergence Herbicides. Field Research Report. Kansas Agricultural Experiment Station Research Reports.

  • Lancaster S.R., D. E. Peterson, W.H. Fick, R.S. Currie, V. Kumar, and J.W. Slocomb (2020) Chemical Weed Control for Field Crops, Pastures, Rangeland, and Noncropland. Report of Progress 1155. Contribution no. 20-103-S from the Kansas Agricultural Experiment Station. https://www.bookstore.ksre.ksu.edu/pubs/SRP1155.pdf

  • Kumar V., R. Liu, D.E. Peterson (2019) Management of Feral Rye with CoAXium® Wheat Production System in Kansas. eUpdate; Issue 769; Published: 10/11/2019. http://bit.ly/2opHNlV

  • Kumar V., R. Liu, T. Lambert, P.W. Stahlman (2019) Herbicide Strategies for Managing Glyphosate- and Dicamba-Resistant Kochia in Roundup Ready 2 Xtend Soybean. Field Research Report. Kansas Agricultural Experiment Station Research Reports: Vol. 5: Iss. 6. https://newprairiepress.org/kaesrr/vol5/iss6/19/

  • Kumar V., R. Liu, T. Lambert, D.E. Peterson, C. Minihan, P.W. Stahlman (2019) Effective Herbicide Options for Controlling Glyphosate-Resistant Palmer Amaranth in Roundup Ready 2 Xtend Soybean. Field Research Report. Kansas Agricultural Experiment Station Research Reports: Vol. 5: Iss. 6. https://newprairiepress.org/kaesrr/vol5/iss6/20 /

  • Kumar V., R. Liu, T. Lambert (2019) Characterization and Management of Glyphosate- and HPPD-Inhibitor-Resistant Palmer Amaranth in Kansas Corn Production. Kansas Agricultural Experiment Station Research Reports: Vol. 5: Iss. 6. https://newprairiepress.org/kaesrr/vol5/iss6/21/

  • Liu R., V. Kumar, R. Perumal, T. Lambert, T. Ostmeyer (2019) Influence of Cultural Practices and Herbicide Programs for Managing Glyphosate-Resistant Palmer Amaranth in Cold-Tolerant Sorghum. Kansas Agricultural Experiment Station Research Reports: Vol. 5: Iss. 6. https://newprairiepress.org/kaesrr/vol5/iss6/22/

  • Obour A.K., J.D. Holman, J.A. Dille, V. Kumar (2019) Effects of Spring-Planted Cover Crops on Weed Suppression and Winter Wheat Grain Yield in Western Kansas. Kansas Agricultural Experiment Station Research Reports: Vol. 5: Iss. 6. https://newprairiepress.org/kaesrr/vol5/iss6/12/

  • Peterson D.E., W. H. Fick, R. S. Currie, V. Kumar, J.W. Slocomb (2019) Chemical Weed Control for Field Crops, Pastures, Rangeland, and Noncropland. Report of Progress 1148. Kansas State University, January 2019. Contribution no. 19-100-S from the Kansas Agricultural Experiment Station.

  • Thompson, C. R., D. E. Peterson, W. H. Fick, R. S. Currie, V. Kumar, and J.W. Slocomb (2018) Chemical Weed Control for Field Crops, Pastures, Rangeland, and Noncropland. Report of Progress 1139. Kansas State University, January 2018. Contribution no. 18-215-S from the Kansas Agricultural Experiment Station.

  • Kumar, V., P. W. Stahlman, G. Boyer (2018) Palmer Amaranth Populations from Kansas with Multiple Resistance to Glyphosate, Chlorsulfuron, Mesotrione, and Atrazine. Kansas Agricultural Experiment Station Research Reports: Vol. 4: Iss. 7. https://doi.org/10.4148/2378-5977.7611

  • Kumar, V., P.W. Stahlman, R. Currie, R. Engel, G. Boyer (2018) Variable Response of Kochia Accessions to Dicamba and Fluroxypyr in Western Kansas. Kansas Agricultural Experiment Station Research Reports: Vol. 4: Iss. 7. https://doi.org/10.4148/2378-5977.7612

  • Kumar V., R. Currie, P.W. Stahlman (2018) Kochia accessions with cross-resistance to dicamba and fluroxypyr identified in western Kansas. eUpdate; Issue 713; Published: 10/5/2018.

  • Peterson D.E., V. Kumar (2018) CoAXium wheat and Aggressor herbicide for grass weed control. eUpdate; Issue 719; Published: 11/09/2018.

  • Jha P., K. McVay, A. Varanasi, V. Kumar. (2013)  Glyphosate-Resistant Kochia in Montana: Herbicide Recommendations and Best Management Practices for Growers. 4602. Montana State University Extension Research Bulletin. Available at http://store.msuextension.org/publications/AgandNaturalResources/4602.pdf

  • Jha P., V. Kumar. (2013)  Effect of Fertilizer N on Crop-Weed Interactions in Montana Cereal Production. 64. Montana State University Extension Agricultural Experiment Station. Available at http://www.sarc.montana.edu/php/Research/ffacts/?id=64





Contact Information


Vipan Kumar PhotoVipan Kumar 
Assistant Professor, Weed Science
KSU Ag Research Center
1232 240th Avenue
Hays, Kansas 67601-9228
(P) 785-625-3425 x214
(F) 785-623-4369
Email: vkumar@ksu.edu
Curriculum vitae


  • Ph.D., Plant Science, 2015, Montana State University, Bozeman, MT.
  • M.S., Agronomy, 2011, Louisiana State University, Baton Rouge, LA.
  • B.S., Agriculture, 2008, Punjab Agricultural University, Ludhiana (Punjab), India.

Research Experience

  • September 2017 to Present, Assistant Professor, Agricultural Research Center, Kansas State University, Hays, Kansas.
  • June 2015 to August 2017, Postdoctoral Research Associate, Southern Agricultural Research Center, Montana State University, Huntley, Montana.