Nearly all herbicide applications in corn, soybean, and wheat require the use of an adjuvant in the spray tank to ensure a successful herbicide application.   While most farmers and applicators are aware of the need for adjuvants, they often don’t know why adjuvants are needed.   The lack of knowledge of why adjuvants are needed often leads to marketing from retailers for unnecessary or inappropriate adjuvant packages for herbicide applications.    Having a basic understanding of what different the types of adjuvants are and why each may be needed in different scenarios can assist farmers in making informed decisions about their adjuvant package purchases.   

Tank mixing of herbicide is also common practice to capture control of a broad spectrum of weed species within a field and has become more common over the past year with a decrease in availability of broad-spectrum herbicides.  Tank mixing of herbicides can also come with pitfall such as physical compatibility leading to products falling out of solution as participants or gel and not being able to be effectively applied with a sprayer.    Tank mixing can also lead to antagonism in which the effectiveness of one herbicide is reduced by a tank mix partner.   Understanding the proper sequence to mix herbicides and what herbicide mixes should be avoided are important aspects of weed control that are often not discussed.    

I developed a tank mix talk and an adjuvant talk that includes a video of tank mixing do’s and don’ts as well as a hands-on demonstration of the value of adjuvants.  I have been asked to present these talks at several counties as well as at the annual ANR Agent update.   The video has also been used heavily by ANR agents in their private applicator training.   It is often assumed that farmers know all these fine details, but all to often that assumption is incorrect as I found out in this case.  This talk will continue to be a primary part of my message in the future.