Herbicide Research

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Robert M. (Bob) Hayes
Director and Professor
Weed Science

Groups and Facilities

(1 mention)

Weed Diagnostics Center 
Diagnostic testing for weeds of crop and non-crop systems including turfgrass, ornamentals, and utility rights of way.

(1 mention)

Turfgrass Weeds 
Turfgrass weed management recommendations and publications.



Promotion and Tenure 2019, 11/12/2019

Dicamba Briefing, 11/27/2017

Neal Stewart Nominated for UT President’s Discover Award, 10/9/2017

UTIA Faculty Spotlight | Dr. Jim Brosnan, 7/18/2017

High Hopes for Tennessee Cotton, 4/17/2017

Answers to Farmers’ Questions, 10/22/2016


(7 mentions)

Weed Research 
A climate that's good for a variety of crops means many types of weeds also thrive. UT AgResearch works to help farmers battle this yearly problem that can greatly affect their yields.

(6 mentions)

Sweet corn 
UT AgResearchers applied herbicides to experimental sweet corn to keep weeds away. But something unexpected happened -- they boosted the nutritional value of the corn.

(4 mentions)

Weed Progress 
Weeds are a nuisance to gardeners, but downright devastating to those who farm for a living. But now experts and farmers say the worst may be behind us.

(1 mention)

Nozzle Selection 
Nozzle selection has been simplified over the years, but different types of nozzles are needed for different situations.

(1 mention)

Weed Olympics 
We've had an Olympic competition here in Tennessee involving ... plants. More specifically, plants we don't like or want. It's called the 'Weed Olympics' on the UT agriculture campus.


Recent Publications

Herbicide application challenges in 2020.  Brosnan, J. T., and G. K. Breeden.  2020.  Turf Magazine. Spring. Pp. 20-22..

Herbicide resistance in annual bluegrass (Poa annua) on Tennessee golf courses.  Brosnan, J. T., J. J. Vargas, G. K. Breeden, and J. M. Zobel.  2020.  Crop, Forage, and Turfgrass Management, (under review; submitted 15 April 2020).

Herbicide resistant weeds in turfgrass: current status and emerging threats Brosnan, J. T., M. T. Elmore, and M. V. Bagavathiannan.  2020.  Weed Technology, 34:424-430.

Herbicide resistance in turfgrass: a chance to change the future? Brosnan, J. T., M. W. Barrett, and P. B. Bhowmik.  2020.  Weed Technology, 34:431-436.

New herbicides for a new year Carroll, D. E., and J. T. Brosnan.  2020.  SportsField Management.

A multi-state survey to determine prevalence of herbicide resistance in annual bluegrass (Poa annua L.) in managed turfgrass systems.  Grubbs, B., D. Hathcoat, S. D. Askew, L. B. McCarty, M. T. Elmore, J. T. Brosnan, J. D. McCurdy, P. E. McCullough, B. J. Unruh, T. W. Gannon, A. J. Patton, and J. E. Kaminski et al..  2020.  Proc. Southern Weed Sci Soc. 72 (in press).

Effect of soil moisture on herbicide efficacy for postemergence goosegrass (Eleusine indica) control.  McNally, B.C., M. T. Elmore, J. T. Brosnan, A. Shekoofa, D. P. Tuck, and J. J. Vargas.  2020.  Northeastern Plant Pest and Soils Conference, 5:35.

Exploring putative herbicide resistance in a goosegrass biotype from Hawaii.  Pritchard, B. D., J. J. Vargas, J. T. Brosnan, and J. Defrank.  2020.  Proc. Southern Weed Sci Soc. 72 (in press).

Caverzan, A., C. Piasecki, G. Chavarria, C.N. Stewart, Jr., L. Vargas. 2019. Defenses against ROS in crops and weeds: the effects of interference and herbicides. International Journal of Molecular Sciences 20: 1086. doi.org/10.3390/ijms20051086.  Caverza, A., C. Piasecki, G. Chavarra, C. N. Stewart, Jr., and L. Vargas.  2019.  International Journal of Molecular Sciences.

Evaluation of the time-of-day effect of herbicides applied POST on protoporphyrinogen IX oxidase-resistant and – susceptible Palmer amaranth (Amaranthus palmeri).  Copeland, J. D., and G. B. Montgomery.  2019.  Weed Technology33:651-657.

Multi-state survey and preliminary screening to evaluate herbicide resistance epidemic in annual bluegrass (Poa annua L.) in managed turfgrass systems.  Grubbs, B., S. D. Askew, L. B. McCarty, M. T. Elmore, J. T. Brosnan, J. D. McCurdy, P. E. McCullough, B. J. Unruh, T. W. Gannon, A. J. Patton, J. E. Kaminski, A Kowaleski, J. S. McElroy, and M. Bagavathiannan.  2019.  ASA-CSSA-SSSA Annual Meeting [USB Flash].

Why Herbicides Sometime Fail: An Overview for Forestry and Wildlife Practices Mercker, D. C., and L. E. Steckel.  2019.  University of Tennessee Extension. W802.