Adjuvant 101: Proper Tank Mixing Order

The effectiveness of a tank mix is dependent on how well products work together in the tank. Getting products to work together well in the tank starts with mixing the right amount of product, in the right order with enough water. When ingredients are mixed out of order, at the wrong rate or with too little water, products can clump and gel instead of remaining in the solution, reducing performance and causing costly cleanup from clogged equipment. 

Before tank mixing, always read and follow label directions to understand rates and ingredients order, and perform a jar test* to ensure compatibility, solubility and stability of ingredients. Any modifications to mixing order, rate, agitation, water volume, pressure of the sprayer and other environmental conditions can decrease performance. 

While most labels should list specific mixing sequences, if instructions are not provided, a simple mnemonic can be used to remember proper tank mix order: A.P.P.L.E.S. 

A.P.P.L.E.S 

The A.P.P.L.E.S. method provides a roadmap for the order chemicals should be added to a tank mix. The A.P.P.L.E.S. method starts by adding hard-to-mix chemicals to water, followed by the addition of easier-to-mix chemicals, with true solutions added last. 

Agitate 

Powder solubles (dry fertilizer, SG, SP) 

Powders dry (DF, WDF, WP) 

Liquid flowables and suspension (ASC, F, ME, SC, SE) 

Emulsifiable concentrates: (EC, EW, OD) 

Solutions: (S, SL) 

As published in the 2021 North Dakota Weed Control Guide, when using the A.P.P.L.E.S. method, each ingredient must be mixed uniformly in solution before adding the next one. For example, a soluble powder must be completely dissolved before adding the next component. Adjuvants are added to the tank mix in the same sequence as pesticides in the same group. For example, ammonium sulfate (AMS), a water conditioner adjuvant, is a soluble powder; an oil adjuvants are emulsifiable concentrates; and most surfactants are solutions. Within each group, always add the pesticide before the adjuvant. For example, add a soluble-powder pesticide before a soluble-powder adjuvant like AMS. 

The Importance of Water 

Water plays a critical role in the effectiveness of a tank mix. Having enough water in the tank before adding other products can make the difference between an effective solution with well mixed ingredients and a solution where ingredients gum up and become ineffective. While it can be frustrating to wait for the tank to fill, starting with half a tank of water is recommended for best results. 

Agitation 

Agitation is important to prevent the solution from becoming stagnant. Without proper agitation, bigger and smaller particles will can be seen as they don’t fully go into solution, known as “falling out”. The tank mix will appear separated and layered, and particles may be lining the tank or floating in solution rather than evenly mixed. The photos below show the difference between a proper and improper tank mix.

Solution showing proper tank mix order with adequate water level and agitation. 

 

Improper tank mix solution showing settling, caking and undissolved herbicide due to inadequate water and agitation.

In the video below, watch as Devin Wirth, CHS Technical Specialist, walks through the right and wrong way to approach a common herbicide tank mix using the A.P.P.L.E.S. method: AMS (8.5lb/100 gallons), Enlist One (32 oz.) and RoundUp PowerMax (32 oz.) at a 10 gallon/acre spray water rate. 

To learn more about tank mix order, agitation or the amount of water needed for a solution, watch the CHS Agronomy “Proper Tank Mix Procedures” video, download the “Using Adjuvants to Improve Crop Protection Performance” white paper or contact your local CHS Agronomy representative. 

*During a jar test, proportionately smaller amounts of tank mix ingredients are mixed in a clear quart jar to ensure compatibility before a full solution is created. When performing a jar test, always wear personal protective equipment (PPE), and follow the mixing order as prescribed on the label. It’s also important to remember that a jar test will only show the physical compatibility of a tank mix. It will not provide information about how an ingredient may inactivate another or cause toxicity. For questions about incompatibility, retailers should talk to their CHS Agronomy representative.