One of the best and worst parts of my job as a weed specialist is troubleshooting field problems. Just never know what you are going to see, and it is always a time to learn and grow. Despite my 32 years of Extension experience, I am often humbled by how much I have yet to learn. 

I have spent much of my peanut research career investigating the effects of non-peanut herbicides on the growth, development and yield of peanut.  Sadly, this is because at some point in my career, I have been in a peanut field where crop injury occurred from off-target movement, sprayer contamination or poor container, or jug, management.

Over the past 27 years, I have collected a lot of data on how peanuts respond to 2,4-D, aminopyralid, dicamba, diuron, glufosinate, glyphosate, imazapyr, picloram, and triclopyr.  For the record, the herbicide that has caused the greatest amount of peanut injury in my research was aminopyralid.  Thus, peanut growers need to take extra precautions when using products such as Forefront, DuraCor, GrazonNext and Milestone on their farms for pasture weed control.  These are awesome pasture herbicides but are not very peanut friendly. 

Here are 10 tips to help all growers get the “Gold” medal in pesticide container management and sprayer cleanout:

Peanut injury from non-peanut herbicides in 2024. Top left = aminopyralid; Top right = 2,4-D LV4; Botton left = glufosinate; Bottom right = glyphosate. (Eric Prostko)

Technically, pods from peanut fields accidently treated with non-labeled herbicides should be tested for residues.  If a tolerance for an herbicide residue has been established by the EPA and the tested pods are below that level, the peanuts can be legally sold.  If an herbicide residue is found to be above the EPA established tolerance or if no EPA tolerance has been established and any residue is found, the crop cannot be legally sold. Pesticide tolerance information can be found in the Code of Federal Regulations.

We are all human and everyone, including me, makes mistakes. I am hopeful that this article inspires growers to think more about slowing down just a bit and paying closer attention to jug management and sprayer cleanout.  One of my goals as I approach the end of my career will be to better educate all growers so that I will never again walk a peanut field that unintentionally was exposed to a non-labeled herbicide. 

As always, good weed hunting!

Prostko is a UGA Extension weed specialist.