Testing Fees & Instructions

The Herbicide Resistance Diagnostic Lab conducts herbicide resistance diagnostic testing on a weed population basis. Email Dr. McElroy or submit a request via our sample submission form for more information below.


All tests are $150 per population.
If collected from a golf course, multiple populations are recommended.

Poa annua and goosegrass — Six modes of action tested: Revolver (foramsulfuron), Roundup (glyphosate), Finale (glufosinate), Princep (simazine), Pendulum (pendimethalin, also informs for Barricade resistance), Ronstar (oxadiazon). Specticle (indaziflam) and PoaCure (methiozolin) provided upon request.

Sedges – Two modes of action tested: Monument (trifloxysulfuron) and Dismiss (sulfentrazone)


Ideally collect plants from treated areas only. For grasses and sedges, cut out plants with a knife in a conical shape (large plugs are not needed). Collect 15-20 plants and place in a gallon zip-loc or other plastic bag. Do not close the bag completely to prevent fungal outbreaks. Pack in a standard box and fill will newspaper or other to prevent movement of plants. Make sure plants are healthy prior to shipment. Try to collect on a Monday or Tuesday and send by next/second day air or delivery to:

Herbicide Resistance Lab
C/O: Dr. Scott McElroy
559 Devall Drive
Auburn, AL 36849

Please notify Dr. Scott McElroy at resistancelab@auburn.edu prior to shipping samples. If you have other samples you would like tested please contact Dr. McElroy for shipping instructions. Testing times vary depending on the number of herbicides to be evaluated.  An estimated evaluation completion will be provided upon receipt. Typical evaluation times for sedge and goosegrass are from 3 to 6 weeks, but interim reports will be sent as some herbicides are screened faster than others.

Please send the following submission form along with plants to aid population tracking.




Testing Fees & Instructions


Sampling & Shipping


Submit Sample Form


Dr. Scott McElroy
Professor (Weed Science/Turf)
Auburn Univ, AL 36849
(334) 844-3992