Page 20 - Griffin Gazette Fall 2015

Bonus
Digital Content
Testing Tank Mix
Compatibility
The following information from Syngenta does
a nice job of detailing the steps used to conduct
a jar test for tank-mix compatibility. GGSPro
seldom recommends use of a tank mix agent
and would suggest that step #2 be disregarded.
—Rick Yates, GGSPro Technical Support Manager
Tank Mix Compatibility Test—
Jar Test and Pesticide Mixing Order
Tank-mixing different products together is common practice in
ornamental and agricultural production. The inability of pesticides,
fertilizers, plant growth regulators and biostimulants to mix together is
referred to as physical incompatibility. Physical incompatibility can be
caused by several factors that include improper mixing, inadequate
agitation, inadequate water carrier volume, poor water quality or lack
of stable emulsifiers in some emulsifiable concentrates. In most cases,
solids settle out of the mixture or the mixture separates into layers
after agitation. Sometimes, the mixture may curdle, gel or become
sludge like. For example, when wettable powders and emulsifiable
concentrates are improperly mixed, they can form a putty or paste
with an oily layer that floats on the top of the tank.
Since many factors influence pesticide compatibility, it is best to
conduct your own jar test to determine compatibility, especially when
applying a new mixture for the first time. The compatibility of pesticide-
fertilizer combinations should also be tested on a small scale before
large batches are mixed. If compatibility issues are detected, adding
a compatibility agent may help maintain the dispersion of the mixture.
Always wear label-required personal protective equipment when
pouring or mixing pesticides.
Tank-mixing Sequence Using the WWW WALES Method
Follow this simple process when adding products:
For a tank-mixture test, prepare on a small scale (quart jar) using
the proper proportions of pesticides and water or fertilizer to ensure
the physical compatibility of the mixture. Consult the product label
for rates. The recommended procedure for conducting jar tank-mix
compatibility tests is as follows:
1. Add 1 pint of carrier (either the water or liquid fertilizer to be used in
the spray operation) to each of two clear 1-qt jars with tight lids.
2. To one of the jars, add ¼ tsp or 1.2 mL of a commercially
available tank-mix compatibility agent approved for this use (¼ tsp is
equivalent to 2 pints/100 gallons spray). Close and seal the lid,
invert the jar, shake or stir gently to ensure thorough mixing of the
compatibility agent.
Not all products are registered in all states. Some pesticides are restricted use in some states or regions and not others. It is the responsibility of the
applicator to read and follow all label directions, remembering that labels may change. Other products may be safe and effective. Rates, application
methods and edible status are detailed in the GGSPro I&F Guides.
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3. Add different formulation types in the sequence indicated below.
After each addition, invert the jar 10 times to thoroughly mix and
simulate agitation in the spray tank. Allow time for complete mixing
and dispersion after the addition of each product.
• Water conditioners
• Water-soluble bags
• Wettable powders
• Water-dispersible granules
• Agitate
• Liquids and flowables- water-soluble concentrates,
oil-based suspension concentrates
• Emulsifiable concentrates and microencapsulates
• Surfactants and other adjuvants, surfactants, oils, fertilizers,
drift retardants
(Fertilizers need to be jar-tested because some mix best when added
first and some best when added last).
4. After adding all ingredients, close the jars and seal the lids. Invert
each jar 10 times to fully mix. Let the mixtures stand for 15-30 minutes
and then assess by looking for separation, large flakes, precipitates,
gels, heavy oily film on the jar or other signs of incompatibility.
Determine if a compatibility agent is needed in the application mixture
by comparing the two jars.
5. If either mixture separates, but can be remixed readily, the mixture
can be sprayed as long as good agitation is used.
6. If the mixtures are incompatible, test the following methods of
improving compatibility: (a) Slurry dry formulations in water before
adding to the jar, or (b) Add the compatibility agent directly into liquid
formulations, before addition to the jar. If these procedures are followed
but incompatibility is still observed, do not use the tank mixture.
7. After compatibility testing is complete, dispose of any pesticide
waste in accordance with the Storage and Disposal section on
the label.
Note: This procedure will only test for physical incompatibility of
various products. It is still possible for some mixtures to be chemically
incompatible i.e., efficacy may be impacted despite no physical
evidence of mixing problems.
©2015 Syngenta. Important: Always read and follow label instructions. Some products may not
be registered for sale or use in all states or counties. Please check with your local extension
service to ensure registration status.