In the vast majority of instances, postemergence herbicides used in peanuts will perform adequately when applied with either a nonionic surfactant (often referred to as "80/20 surfactant") or crop oil concentrate. There are other products sold, including methylated seed oils and silicone-based adjuvants. There are combinations of these as well. These do perform well and in some cases they may outperform the standard crop oil concentrate and nonionic surfactant products. However, in summer months when most of our postemergence herbicides are being applied, crop oil concentrate and nonionic surfactants applied based on the product labels are adequate for herbicide performance.

With that said, poor weed control with postemergence herbicides is most often related to marginal effectiveness of a herbicide on the weed in question, applying a rate that is too low or when the weed is too big, applying the herbicide when the weed is stressed, or when applying multiple products in the same tank. Water quality can have a negative impact on some herbicides. Of course, we have cases where weeds are resistant to herbicides, but a lot of the issues we have with herbicide performance are related to when and how we spray. For contact herbicides, we often drive to fast and have too low of a spray volume.