This document provides definitions and descriptions of various types of adjuvants that can be added to pesticide mixtures. It defines polar vs non-polar compounds and ionic vs non-ionic compounds. It then describes different types of adjuvants including surfactants, wetting agents, penetrants, spreaders, stickers, drift control agents, and pattern indicators. The purpose of adjuvants is to modify the behavior and effectiveness of pesticides by changing properties like how evenly they spread, how well they penetrate surfaces, their ability to form films or adhere to surfaces, and reducing drift.

1. Adjuvants
An overview of the adjuvants in
use in Region 8.
BY Ali Rehman Afridi

2. Adjuvants
Any material added to a pesticide mixture
to modify its behavior; includes wetting
agents, spreader stickers, other
surfactants, penetrants, and drift control
agents

3. Adjuvants – some definitions
Polar vs. non-polar
Polar compounds are
compounds which have, due to
their structure, have a definite
imbalance in charge – resulting in
a positive and a negatively
charged end - +
Polar bear?

4. Adjuvants – some definitions
Polar vs. non-polar
Non-polar compounds are
compounds which have evenly
distributed charge throughout their
molecules

5. Adjuvants – some definitions
R +
-
Polar Non-polar

6. Adjuvants – some definitions
Polar vs. non-polar
Polarity in a chemical aids in
spreading the chemical over a
polar surface or in penetrating one

7. Adjuvants – some definitions
Ionic vs. non-ionic
In solution ionic molecules
separate into positively and
negatively charged subparts (ions)
while non-ionic molecules do not

8. Adjuvants – some definitions
Ionic vs. non-ionic
R +
-
Ions from an
ionic
compound
Non-ionic
molecule

9. Adjuvants – some definitions
Ionic vs. non-ionic
Ions from an ionic compound can
interfere with the activity of a polar or
an ionic pesticide while non-ionic
compounds do not

10. Adjuvants

11. Surfactant
Any material added to a pesticide
formulation which is designed to modify
the surface characteristics of the target
organism

12. Surfactants

13. Wetting Agent
Any material added to a pesticide mixture
which serves to make the surface
“wetter” so as to allow more rapid
spread of the pesticide on the target
– often called a ‘spreader’
Without
wetting agent
With a wetting
agent

14. Wetting agents

15. Penetrant
Any material which modifies the target
surface in a way which allows more
rapid penetration of the surface of the
organism by the pesticidal formulation

16. Penetrants
Mineral oil Napthenic oil
Diesel oil

17. Penetrants
Vegetable oil Organic silicone

18. Penetrants
Products designed to create invert
emulsions (oil in water)

19. Spreader
Any material added to a pesticide
formulation which improves the
formulations ability to rapidly form a film
on the target surface – generally
interchanged with “wetting agent”

20. Sticker
Any material added to a formulated
pesticide which improves the ability of
the pesticide to adhere to the target
surface

21. Stickers

22. Drift Control Agent
Materials added to a mixture to increase
the size of droplets and decrease the
tendency of the pesticide to drift off-
target

23. Drift control agents

24. Materials added to a formulation which
marks a treated stem so that later
identification of those treated vs. not
treated is simplified
 Dyes in either amine or ester formulations
are the most common pattern indicators

25. Pattern indicators