Skip Ribbon Commands
Skip to main content
Navigate Up
Sign In

​Herbicide Resistance Screening & Confirmation

A weed is deemed to be herbicide resistant when it survives an application of herbicide that is normally lethal. Increased evolution of herbicide resistant weeds is a major agricultural problem challenging managers of both crop and non-cropland systems. The University of Tennessee Weed Diagnostics Center offers several tests to screen for and diagnosis resistance in weeds.
​​​​​
​​

​Tradit​ional Whole Plant Resistance Screening

Fresh plant samples should be mailed to the following address:FullSizeRender.jpg

UT Weed Diagnostics Center
252 Ellington Plant Sciences Bldg. 
2431 Joe Johnson Dr. 
Knoxville, TN 37996
Attention: Jose Vargas

Plants will be cultured in a germination chamber in order to produce seed for resistance screening. Samples will be seeded along with known resistant and susceptible standards and exposed to a discriminatory rate of a single herbicide. All tests will be replicated three times. In the event a known resistant standard is not available for the weed submitted, samples will be screened with known susceptible sample of the same species and exposed to a discriminatory rate of herbicide. 

In most cases, a report detailing results and providing control recommendations will be provided 16-20 weeks after sample submission.​


Cost

$1499 per sample for Tennessee residents / $1599 per sample for non-Tennessee residents

Submit a Sample for Traditional Whole Plant Resistance Screening

Molecular Resistance Confirmation

Fresh plant samples should be mailed to the following address: 

UT Weed Diagnostics Center
252 Ellington Plant Sciences Bldg. 
2431 Joe Johnson Dr. 
Knoxville, TN 37996
Attention: Jose Vargas

Plants will be cultured in a germination chamber and DNA will be extracted from plant tissue and analyzed for target site mutations associated with herbicide resistance. In most cases, individuals submitting a sample will receive a report detailing results that also provides control recommendations within 3-5 weeks of sample submission.  

Cost

$2999 per sample for Tennessee residents / $3299 per sample for non-Tennessee residents

Submit a Sample for Molecular Resistance Confirmation

​​

​Rapid Resistance Screening

Fresh plant samples should be mailed to the following address: agar.jpg

UT Weed Diagnostics Center
252 Ellington Plant Sciences Bldg. 
2431 Joe Johnson Dr. 
Knoxville, TN 37996
Attention: Jose Vargas
 

Plants will be established in agar culture using modified methods of Kaundun et al. (2011)​​. When available, known resistant and susceptible lines of the same weed species will be established in agar as well. In the event a known resistant standard is not available for the weed submitted, samples will be screened with a known susceptible sample of the same species and exposed to a discriminatory rate of herbicide.  A discriminatory rate of an herbicide of interest will be loaded into the agar and responses will be monitored. All diagnostic tests will be replicated five times. ​ 

At present, this test can only be used to screen for acetolactate synthase (ALS; e.g., trifloxysulfuron), dinitroaniline (e.g., prodiamine) and 5-enolpyruvylshikimate-3-phosphate synthase (e.g., glyphosate) inhibitor resistance. However, it will be adjusted to screen for resistance to other modes of action in the future. Not all weed species can be tested using this rapid method. Please consult the WDC with specific questions about plant material to be tested.

In most cases, a report detailing results and providing control recommendations will be provided 2-3 weeks after sample submission.​ An example summary report can be accessed here.​​

Cost

$649 per sample for Tennessee residents / $749 per sample for non-Tennessee residents

Submit a Sample for Rapid Resistance Screening​

​​​
Sign In