Even with the right products, the right adjuvants and water conditioners, problems can still occur if not added in the right sequence. "We've been used to only one adjuvant with water soluble glyphosate. Now, with all the things being mixed in for resistant weeds, getting the sequence right is a big part of it," advises Reiss.

Precision Laboratories has a free Mix Tank smartphone app designed to help resolve mixing sequence questions and much more. The database includes more than 1,300 crop protection products from more than 17 manufacturers. However, as good as the award-winning app is, Reiss admits that it can't answer every question or prevent problems.

"The app will tell you the right mixing sequence, but it may not tell you if something is flat out incompatible," he warns. "When doing a complex tank mix, always do a compatibility test first. It lets you see what could happen if a mix sits overnight or over a weekend. Suspension concentrates can be stable in the jug with the product, but in the spray solution, they may settle out in as little as 45 minutes."

Spandl endorses the importance of compatibility tests. "There are so many different tank mixes, no one can know if they all work," he advises. " Take a little product and add it to a quart of water. It's better to end up with a quart of cottage cheese versus 1,000 gallons of it."