Pesticide formulation

Pesticide Formulations and Adjuvants
Dr. Subhomay Sinha

What is a Pesticide Formulation?
A homogeneous and stable mixture of active and inert ingredients which make the final
product simpler, safer, and more efficacious to apply to a target pest.

Why to Formulate Pesticides???
• Pesticides are rarely applied in their
technical form.
• They are usually formulated to improve
– Handling
– Storage
– Application
– Effectiveness
– Safety
Active Ingredient is rarely suitable for field
application. So they are formulated in a
manner that increase pesticide effectiveness
in the field.
What are pesticide formulations???
A pesticide formulation is a mixture of chemicals which effectively controls a pest.
Formulating a pesticide helps to improve its storage, handling, safety, application, or
effectiveness. Pesticide products sold as concentrates must be mixed with water, or some
other carrier, before being applied.

Terminology for Formulations
• A.I. = Active Ingredient, the actual chemical in the product
mixture that controls the pest.
• Inert ingredient = other materials added with the A.I.
when the product is formulated.
• Formulation = the way a pesticide is prepared for practical
use.
• Carrier = inert liquid or solid added to an active ingredient
to prepare a pesticide formulation.

• Diluent = Any liquid or solid material used to
dilute an active ingredient. In liquid formulations,
water or oil is used; in dry formulations, talc, clay
or other fine dust is used.
• Emulsifier = A chemical that aids in suspending
one liquid in another.
• Emulsion = A mixture of one liquid in another
liquid.

• Wetting agent = A chemical which causes a liquid
to contact surfaces more thoroughly.
• Suspension = A mixture of fine solid particles in a
liquid.
• Soluble = A substance, dissolves in a liquid.
• Surfactant = Increases the emulsifying, dispersing,
spreading, and wetting properties of a
formulation.

Why We Add Inert Materials to the Formulation?
1. For ease of pesticide product handling.
2. Inert materials make measuring and mixing pesticides
easier.
3. To provide more safety.
4. Makes the Active Ingredient to work better.
• Better penetration
• More selectivity
• Increased effectiveness

READY-TO-USE FORMULATIONS (RTU FORMULATIONS):
CAN BE APPLIED DIRECTLY WITHOUT ANY DILUTION
They contain small amounts of active ingredient (often 1% or less a.i. per unit volume).
Some contain petroleum-based solvents; others are water-based. RTU formulations are
already diluted and may be sold in containers that serve as applicators. Example of RTU
formulations include aerosols (A), granules (G), and most baits (B). They are especially
useful for structural and institutional pests and for household use. Major disadvantages of
Ready to use pesticide formulations include limited availability and high cost per unit of
active ingredient.

Liquid Formulations
Most liquid formulations are diluted with water to make a finished spray. The three main types
of liquid formulations are solutions (SL), suspensions (SC), and emulsions (EC). Besides there
are Water Soluble Concentrate (WSC), Liquid Bait (L.B.), Oil Dispersion (O.D.), Invert emulsion
(I.E.), Suspoemulsion (S.E.), Microemulsion (M.E.), Emulsion in water (EW).
Liquid formulation
E.C. W.S.C. L.B. O.D. I.E. S.E. S / CS/SL
U.L.V.
M.E. S.C./F/ L E.W.

A solution is made by dissolving a substance in a liquid. A true solution is a mixture that
cannot be separated by a filter or other mechanical means. Normally, it will not separate or
“settle out” into distinct parts after being mixed. Light can penetrate most solutions.
A suspension is an even mixture of very small solid particles throughout a liquid. A
suspension formulation that has not been used for some time must be shaken well to mix
the liquid and solid portions evenly before pouring it into the spray tank. Water is added to
make a finished spray mixture.
There must be enough agitation to keep the product evenly distributed in the spray tank
during application. Most suspensions are cloudy or opaque; light cannot pass through them.
An emulsion is a mixture of droplets of one liquid in another liquid. Each ingredient keeps its
unique properties and identity.
In an emulsion concentrate formulation, the active ingredient is dissolved in an oil-based
solvent. An emulsifier allows the active ingredient and the solvent to mix evenly with water
before application. Some agitation may be necessary in the spray tank to keep an emulsion
from separating. As a rule, emulsions have a “milky” appearance.
Emulsion

Common Liquid Formulations
1. Emulsifiable Concentrate (E or EC)
EC formulations usually contain an oil-soluble liquid active ingredient, a petroleum-
based solvent, and an emulsifier (mixing agent). The emulsifier allows the active
ingredient and the solvent in the formulation to mix with water, these form an
emulsion. ECs are versatile formulations that can be applied with many types of
sprayers.
The milky colored appearance when mixed
with water is typical of emulsifiable
concentrates.

Emulsifiable Concentrate (E or EC)

2. Solutions (S, CS)
Some pesticide active ingredients dissolve readily in a liquid solvent, such as water or a
petroleum-based diluent. When mixed, they form a solution that does not settle out or
separate. Formulations of these pesticides usually contain the active ingredient, solvent
(carrier or diluent), and one or more other ingredients. No emulsifier is required. Solutions
are suitable for any type of sprayer and are registered for many sites.

Ultra-low Volume (ULV) Solution formulation.
These concentrates may approach 100 percent active ingredient. They are designed to be used
as it is or to be diluted with only small quantities of a specified carrier.
These special-purpose formulations are used mostly in outdoor applications, such as in
agricultural, forestry, ornamental, and mosquito- control programs.
Advantages:
• Relatively easy to handle, transport, and store.
• Remain in solution; little agitation required.
• Not abrasive to equipment.
• Will not plug screens and nozzles.
• Leave little visible residue on treated surfaces.
Disadvantages:
• Difficult to keep pesticide on target—high drift hazard.
• Specialized equipment required for field application.
• Easily absorbed through skin of humans or animals.
• Solvents may cause rubber or plastic hoses, gaskets, and pump parts to deteriorate.
• Calibration and application must be done very carefully because of the high concentration
of active ingredient.

3. Emulsions in Water (EW) Formulation
An emulsion in water formulation (EW) is the dispersion of a liquid active ingredient in
water. These formulations have reduced dermal toxicity and lower potential for harming
the environment. EWs are less likely to damage tender plant foliage because they do not
contain the solvents found in EC formulation.
Concentrated aqueous emulsion (EW) formulations are stable emulsions of an insoluble
liquid in a continuous water phase. The insoluble liquid can be either a liquid active
ingredient or a solid active ingredient dissolved in a solvent.

4. Flowables (F, L, or SC)
Some active ingredients will not dissolve in either water or oil so they are impregnated in
a dry carrier, such as clay, which is ground into a fine powder. The powder is suspended in
a small amount of liquid to make the thick liquid formulation.
Abbreviations used include “F” for flowable, "L" for liquid, and "SC" for suspension
concentrate.
Flowables are often used for the same types of pest control operations as ECs.

Suspension concentrate formulation
Suspension concentrate (SC) formulations are a solid active ingredient dispersed in water.
SCs have grown in popularity due to benefits such as absence of dust, ease of use and
effectiveness when compared to formulation types such as emulsifiable concentrate (EC)
and wettable powder (WP). To formulate a stable SC, the active ingredient must remain
insoluble under all temperature conditions.

5. Microemulsion (ME)
A micro-emulsion (ME) is defined as a system of oil, water and surfactants that forms a single,
optically clear and thermodynamically stable emulsion.
MEs are water based formulations with a very small emulsified droplet size; this makes the
formulation transparent. They are thermodynamically stable over a wide temperature range due
to this very fine droplet size, usually between 0.01 and 0.05 μm.

Benefits of Micro-emulsions
Thermodynamically stable therefore have increased shelf life.
Low solvent level.
Easy to transport and store.
High flash point and safe handling.
Improved bio efficacy due to the solubilisation of the active ingredient in
the micro droplets.
Low viscosity so easier to handle.
Limitations of Micro – emulsion
Low active ingredient content.
Require high surfactant level to form Tank Mixture.

6. Oil Dispersion (OD)
An oil dispersion (OD) formulation is a solid active ingredient dispersed in oil. The oil can vary
from paraffinic to aromatic solvent types and vegetable oil or methylated seed oils. Ideally
the active ingredient is uniformly suspended in the oil phase.
ODs are an excellent delivery system for water sensitive active ingredients such as
sulfonylureas. However, ODs have extended to other active ingredients due to their better
spray retention, spreading and foliar uptake as the carrier oil often acts as an adjuvant.

7. Suspoemulsion (SE)
Suspo-emulsion (SE) formulations are used to combine two active ingredients with very
different physical properties into one formulation. They are a combination of
suspension concentrate (SC) and concentrated aqueous emulsion (EW) technologies.
The advantages are that it is possible to formulate multiple active ingredients together,
broadening the spectrum of activity and eliminating the disadvantage of tank-mix
incompatibility.
Benefits
• Incorporates multiple active ingredients with
different solubility or melting points.
• A mixture of active ingredients is often used to
provide a broader spectrum of pest control.
• Formulating active ingredients together
eliminates the need for tank mixing which can
lead to incompatibility in the spray tank
Limitations
• The surfactant system needs to support both an
insoluble organic solid and a liquid.
• Partial solubility of the active ingredients in water or oil
phases causes stability problems.
• Generally they are highly loaded so can have long term
stability issues if the correct surfactants are not used

Water-soluble concentrates form a true solution when added to water and are applied
with water as the carrier. The a.i. of this pesticide usually have an amine (ammonium salt)
or mineral salt in the molecule that enables water solubility. These formulations are
essentially nonvolatile. Agitation is not necessary to maintain the pesticide in solution.
Advantages:
• Readily mixes with water,
• Equipment cleans up easily,
• Essentially non-volatile,
• Not abrasive to equipment,
• Will not plug strainers
• No agitation necessary.
Disadvantages:
• Eye irritation with some salts,
• Some products are reactive with unlined
steel tanks.
• Mixing concentrates together could have
compatibility problems.
8. Water-Soluble Concentrate (WSC)

Because oil evaporates more slowly than
water, invert emulsion droplets shrink less;
therefore, more pesticide reaches the target.
The oil helps to reduce runoff and improves
rain resistance.
9.

THE ADVANTAGES OF Ready to use AEROSOL FORMULATION ARE:
• Ready to use
• Portable
• Easily stored
• Convenient way to buy a small amount of a pesticide
• Retain potency over fairly long time.
THEIR DISADVANTAGES ARE :
• Practical for only very limited uses
• Risk of inhalation injury
• Hazardous if punctured, overheated, or used near an open flame
• Difficult to confine to target site or pest
THE ADVANTAGES OF Ready to use AEROSOL FORMULATION ARE:
• Ready to use
• Portable
• Easily stored
• Convenient way to buy a small amount of a pesticide
• Retain potency over fairly long time.
THEIR DISADVANTAGES ARE :
• Practical for only very limited uses
• Risk of inhalation injury
• Hazardous if punctured, overheated, or used near an open flame
• Difficult to confine to target site or pest

Aerosol Formulations for Smoke or Fog Generators
These aerosol formulations are not under pressure. They are used in machines that
break the liquid formulation into a fine mist or fog (aerosol) using a rapidly whirling disk
or heated surface. These formulations are used mainly for insect control in structures
such as greenhouses and warehouses and for mosquito and biting fly control outdoors.
Advantages:
Easy way to fill entire enclosed space with
pesticide.
Disadvantages:
Highly specialized use and equipment.
Difficult to confine to target site or pest.
May require respiratory protection to prevent risk
of inhalation injury.

11. Liquid Baits
• An increasing number of insecticides and rodenticides are being formulated as liquid
baits.
• Liquid rodenticides are mixed with water and placed in bait stations designed for these
products. They have two major benefits. Liquid rodenticides are effective in controlling
rodents, especially rats, in areas where they cannot find water.
• Liquid insecticide baits are used primarily by the structural pest control industry for
controlling ants and, to a lesser extent, cockroaches. They are packaged as ready-to-use,
sugar-based liquids placed inside bait stations.
• Liquid insecticide ant baits have a number of advantages. They are very effective against
certain species of sugar-feeding ants. These ants typically accept and transfer liquid baits
into the ant colonies. However, some ants will not feed on liquid baits. Liquid baits also
must be replaced often.

Solid / Dry formulations
Solid formulations are of two types : Ready to use formulations and Dry concentrates, which
must be mixed with water to be applied as spray. Dust, Granules and Pellets are ready to use
formulation, while Wettable Powders, Dry flowable, Water dispersible granule, Encapsulated
granule and Soluble powders are to be mixed with water.
Solid formulation
Dust. Granule. Pellets Baits W.P.
Paste /
Gel
SP WDG / DF M.E. WSP.

Common Solid Formulations
1. Granule (G)
• This is a ready-to-use dry mixture of a small amount of active ingredient with inert
carriers. Most are made by applying a liquid formulation of the active ingredient to
coarse particles (granules) of some porous material such as clay, sand or plant material.
• Granule particles are much larger than dust particles; will pass through a 4-mesh sieve
but not through an 80-mesh sieve.
• The amount of active ingredient usually ranges from 1 to 15 percent. They are most
often used as soil treatments, applying through broadcasting method.
• Granular formulations should always be used dry. Never mix them with water. Granules
should not be applied to frozen soil or on steep slopes. The relative large particle size of
granules minimizes drift potential and reduces inhalation hazard.
• After application, the active ingredient is slowly released. Rainfall or watering usually is
needed to activate the product.
• Granular formulations are mostly used to apply chemicals to the soil to control weeds,
nematodes, or soil insects.
• Granular formulations are used to deliver systemic pesticides which are taken up by
plant roots. They also are used in aquatic situations to control mosquito larvae and
aquatic weeds.

Advantages:
-ready to use,
-easy to apply,
-will fall through dense foliage,
-minimizes drift potential,
-reduced inhalation and dermal hazard
-simple application equipment.
Disadvantages:
-limited foliage use,
- needs moisture to activate its action,
-bulk quantities necessary : logistical problem,
-can be harmful to nontarget organisms such as
birds,
-difficult to spread uniformly around obstacles.
Granule (G)

2. Pellet (P)
• Pellets are similar to granules, but their manufacture is different.
• The active ingredient is combined with inert materials to form a slurry. This slurry is then
extruded under pressure through a die and cut at desired lengths to produce a particle that is
relatively uniform in size and shape, but is much larger than a granule.
• Pellets are similar to granules, as they are ready to use, are applied in the dry form.
• Pellets contain a small amount of active ingredient (usually 10 to 20 percent by weight),
combined with inert carrier. Pelleted formulations may be applied through broadcasting method,
and are used for soil treatment. While drift is not a problem with this formulation, pellets should
not be applied to frozen soil, steep slopes or in close proximity to root systems. Pellets provide a
high degree of applicator safety.
Advantages:
-ready to use,
-easily applied by hand,
-reduced applicator hazard,
-minimum drift potential, and
-effective spot treatment method.
Disadvantages:
-active ingredients are expensive,
-bulk quantities necessary : logistical problem,
-difficult to spread uniformly around obstacles.

3. Dust (D) Formulation
Most dust formulations are ready to use and contain a low percentage of active
ingredients (usually 10 % or less by weight), plus a very fine, dry inert carrier made
from talc, chalk, clay, nut hulls, or volcanic ash.
Dusts are always used dry and can easily drift to non-target sites. They are used for
seed treatments and sometimes for agricultural or home gardening applications.
In structures, dust formulations are used in cracks and crevices and for spot treatments
to control insects such as cockroaches, ants, etc.
Advantages:
• Most are ready to use, with no mixing.
• Effective where moisture from a spray
might cause damage.
• Require simple equipment.
• Effective in hard-to-reach indoor areas.
Disadvantages:
• Easily drift off-target during application.
• Residue easily moved off-target by air
movement or by water.
• May irritate eyes, nose, throat, and skin.
• Will not stick to target surfaces.
• Dampness can cause clogging and lumping.
• Difficult to get an even distribution of
particles on surfaces.

4. Baits (B) Formulation
A bait formulation is an active ingredient mixed with food or another attractive substance.
The bait either attracts the pests or is placed where the pests will find it.
Pests are killed by eating the bait that contains the pesticide. The amount of active
ingredient in most bait formulations is quite low, usually less than 5 %.
Baits are used inside buildings to control ants, roaches, flies, other insects, and rodents.
Outdoors, they sometimes are used to control snails, slugs, and insects such as ants and
termites. Their main use is for control of vertebrate pests such as rodents, other mammals,
and birds.
Advantages:
• Ready to use.
• Entire area need not be covered, because pest
goes to bait.
• Controls pests that move in and out of an area.
Disadvantages:
• Can be attractive to children and pets.
• May kill domestic animals and non-
target wildlife outdoors.
• Pest may prefer the crop or other food
than the bait.
• Dead vertebrate pests may cause odour
problems.

Different Baits (B) Formulations

Pastes and gels are mainly used in the pest-control industry for ants and cockroaches.
Insecticides formulated as pastes and gels are used in cockroach control. They are designed to
be injected or placed inside small cracks and crevices of building elements where insects tend to
hide or travel.
Two basic types of tools are used to apply pastes and gels—syringes and bait guns. The
applicator forces the bait out of the tip of the device by applying pressure to a plunger or trigger.
5. Pastes, Gels, and Other Injectable Baits
bait guns
gels—syringes

Wettable powders are dry, finely ground formulations that look like dusts. They usually mixed
with water to form a suspension for application as a spray. Wettable powders contain 5 - 95 %
active ingredient by weight; usually 50 % or more.
Wettable powders are finely ground solids, typically mineral clays, to which an active
ingredient is sorbed.
The particles do not dissolve in water. Wettable powders form a suspension, rather than true
solution when added to water. They settle out quickly unless constantly agitated to keep them
suspended. They can be used for most pest problems and in most types of spray equipment
where agitation is possible.
6. Wettable Powders (WP or W)
Advantages:
• Easy to store, transport, and handle.
• Less likely than ECs and other
petroleum-based pesticides to cause
unwanted harm to treated plants,
animals, and surfaces.
• Easily measured and mixed.
• Less skin and eye absorption than ECs
and other liquid formulations.
Disadvantages:
• Inhalation hazard to applicator while
measuring and mixing the concentrated
powder.
• Requires good and constant agitation
(usually mechanical) in the spray tank.
• Abrasive to many types of pumps and
nozzles, causing them to wear out quickly.
• Difficult to mix in very hard, alkaline water.
• Often clog nozzles and screens.
• Residues may be visible on treated surfaces.

Soluble powder formulations look like wettable powders. However, when mixed
with water, soluble powders dissolve readily and form a True Solution, where
Wettable Powder forms a Suspension.
No additional agitation is necessary. The amount of active ingredient in soluble
powders ranges from 15 to 95 % by weight; it usually is more than 50 percent.
Soluble powders have all the advantages of wettable powders and none of the
disadvantages, except the inhalation hazard during mixing. Few pesticides are
available in this formulation because very few active ingredients are readily
soluble in water.
7. Soluble Powders (SP or WSP)

Water-dispersible granules, also known as Dry Flowables, are like wettable powders,
except instead of being dust-like, they are formulated as small, easily measured granules.
Water-dispersible granules must be mixed with water to be applied. Once in water, the
granules break apart into fine particles similar to wettable powders and form suspension
but not True solution.
WDG formulation requires constant agitation to keep it suspended in water. The
percentage of active ingredient is high, often as much as 90 percent by weight.
Water-dispersible granules share many of the same advantages and disadvantages of
wettable powders, except they are more easily measured and mixed. Because of low
dust, they cause less inhalation hazard to the applicator during handling.
8. Water-dispersible Granules (WDG) or Dry Flowables (DF)

9. Microencapsulated Materials (M or ME)
Here liquid or dry pesticide particles placed in a plastic coating to produce a
microencapsulated formulation. Microencapsulated pesticides are mixed with water
and sprayed in the same manner as other sprayable formulations. After spraying, the
plastic coating breaks down and slowly releases the active ingredient.
Microencapsulated materials have several advantages:
• Highly toxic materials are safer for applicators to mix and apply.
• slow release of the active ingredient prolongs its effectiveness, allowing for fewer
and less precisely timed applications.
• The pesticide volatilizes more slowly; less is lost from the application site.
Microencapsulated materials, however, pose a special hazard to bees. Foraging bees
may carry microencapsulated materials back to their hives because they are about the
same size as pollen grains. As the capsules break down, they release the pesticide,
which results pesticide poisoning of the bees.

Water-soluble packets reduce the mixing and handling hazards of some highly toxic
pesticides. Manufacturers package precise amounts of wettable powder or soluble
powder formulations in a special type of plastic bag. When you drop these bags into a
water filled spray tank, they dissolved / suspended and release their contents to mix
with the water.
10. Water-soluble Packets (WSB / WSP)

Insect Attractant
formulations

Insect Lure Trap
Yellow sticky trap Chemical attractant trap Fly trap
Mosquito trap
Wasp trap
Insect
Attractant
Traps.

Insect Repellent
formulations
Insect Repellent
formulations

Agricultural Spray Adjuvants
An Agricultural Spray Adjuvant is any additive used in pesticide spray
mixture to increase its biological activity and/or to modify various
physical properties of a spray solution.
Agricultural Spray Adjuvants Are Classified Into Four Categories
• Activator Adjuvants
– Enhance Pesticide Performance
• Surfactants, Crop Oil Concentrates, Methylated Seed Oils, Fertilizer Solutions, Penetrants
• Spray Modifier Adjuvants
– Affects Physical Properties Of Spray Solutions
• Stickers, Deposition Aids, Drift Retardants, Evaporation Aids
• Utility Modifier Adjuvants
– Minimize Handling and Application Problems
• Compatibility Agents, Buffering Agents, Defoamers, Anti-foams
• Utility Products
– Minimize Application Problems
• Foam Markers, Tank Cleaners

Agricultural spray adjuvants are used to enhance the effectiveness of pesticides such as
herbicides, insecticides, fungicides and other agents that control or eliminate unwanted pests.
Agricultural spray adjuvants are not themselves active in controlling or killing pests. Instead,
these additives modify some property of the spray solution, which improves the ability of the
pesticide to penetrate, target or protect the target organism.
The proper adjuvant may reduce or even eliminate spray application problems, thereby
improving overall pesticide effectiveness.

Activator adjuvants
The main purpose of activator adjuvants is to
improve the "activity" of the pesticide product. These
improvements--both physical and chemical generally
leads to better absorption and, as a result, a more
efficient use of the pesticide.
Activator adjuvants include Surfactants, oils, and
nitrogen-based fertilizers.
SURFACTANTS, also called wetting agents and
spreaders, physically change the surface tension of a
spray droplet. For a pesticide to perform its function
properly on a plant, the spray droplet must be able to
wet the foliage and spread out evenly. Surfactants
make the area of pesticide coverage larger, which
increases the pest's exposure to the chemical.
Without proper wetting and spreading, spray
droplets often run off or fail to provide good
coverage to the surfaces.
ACTIVATOR ADJUVANTS

Classification of Surfactants (Wetter-spreaders or Wetting agents)
Surfactants are classified by the way they ionize, or split apart, into electronically charged
molecules called ions. We can classify surfactants into four types:
Anionic Surfactants (negative charge) : Most effective when used with contact pesticides.
Cationic Surfactants (positive charge): mostly they are phytotoxic. They should be used in
combination with other types of surfactants.
Nonionic Surfactants (no charge): Composed of alcohols and/or fatty acids and are compatible
with most pesticides. Helps pesticide sprays to penetrate into plant cuticles. Often used with
systemic pesticides. It is the most commonly used surfactant.
Organo-silicone Surfactants (a newer group taking the place of nonionic surfactants): Reduces
surface tension, increases spreading ability, and improves rainfastness (amount of time between
pesticide application and rainfall)
Surfactants as Activator Adjuvants

Reduce the surface tension
Prevent beading of droplets
Enable uniform coverage of pesticides
Help pesticides to penetrate the surface of the leaf faster and
more evenly
Ultimately, result in a better crop yield
For a pesticide to be effective, spray droplet must: -
Spread out uniformly over leaf surface
Penetrate into the leaf surface
Pesticides do not effectively penetrate leaf surface due to: -
Wax or oils present on leaf surface
Surface tension between leaf surface and spray droplet.
Need of a surfactaNt

test for ideal surfactaNt : Mustard test
Take one glass of water.
Add few drops of mustard oil.
It form a bead like structure over the surface of water.
 Then add few drops of Surfactant in it, and stir well with a glass rod.
After adding the Surfactant and subsequent stirring, if the oil completely
dissolve in water, then it is ideal for use.

Commercially available Adjuvants

Oils as Activator ADJUVANTS
Crop oil is generally 95 - 98 % paraffin or naptha-based petroleum oil with 1 - 2 % surfactant /
emulsifier. Crop oils promote the penetration of a pesticide spray either through a plant's waxy
cuticle or through an insect's tough, chitinous shell. Traditional crop oils are more commonly used for
insect and disease control and rarely with herbicides.
Crop oil concentrates (COCs) are made up of 80 - 85 % emulsifiable petroleum-based oil and 15 - 20
% nonionic surfactant. Crop oil concentrates have the penetration properties of oil and the
spreading properties of a surfactant. COCs are often used with post-emergence herbicides. It aids
penetration through the leaf cuticle.
Vegetable oil concentrates (VOCs) are made up of 80 - 85 % crop derived seed oil (usually cotton,
linseed, soybean, or sunflower oil) and 15 - 20 % non-ionic surfactant. To improve their performance,
many VOCs have undergone a process called esterification, which increases the oil-loving characteristics
of the seed oil and results in a methylated seed oil (MSO), which also helps cuticular penetration.
The three types of oil-based adjuvants include CROP OILS, CROP OIL CONCENTRATES, and
VEGETABLE OIL CONCENTRATES.
Nitrogen-based Fertilizers As Activator Adjuvants
Improved herbicidal activity has been shown by adding ammonium sulfate or urea-ammonium
nitrate to the spray mixture.

Other types of Adjuvants : STICKERS, BUFFERS, FOAM RETARDANTS, DRIFT RETARDANTS, etc
Stickers
Sticker is a substance added to a pesticide spray mixture to help it to stick to the sprayed
surface.
A sticker can perform three types of functions:
• It can increase the adhesion or “stickiness” of spray particles that otherwise might be easily
dislodged from a leaf surface.
•It can also reduce evaporation of the pesticide.
• It provide a waterproof coating to the pesticide, after it is sprayed to the plant.
Buffers
Buffers contain organic acids, which will lower the pH or acidity of the water and tend to
stabilize the pH at an acceptable value. The more alkaline the water, the greater the amount of
buffer that will be required.
Foam retardants
Some formulations of agricultural chemicals will create foam in some spray tanks. Foam
retardants prevent the formation of such types of foam in spray mixture.
Drift retardants
Drift is a function of spray droplet size. Drops with diameters of 100 microns (0.1mm) or less
contribute to the bulk of the drift. Drift retardant increases the tensile strength of water and
also increase the average drop size, resulting in lesser drift problem.

Other types of Adjuvants : PENETRATORS, WATER CONDITIONING AGENTS, HUMECTANTS,
DEPOSITION AIDS, COMPATIBILITY AGENTS, SUSPENSION AGENTS, COLORANTS etc
Penetrators: Enhance uptake of pesticides through target pests surfaces.
Water Conditioning Agents: Reduce the antagonistic affects of impurities (Ca, Mg, Mn, Fe, etc.)
found in water carrier. Potentially greater pesticide efficacy results.
Humectants: Increase the drying time of spray droplets, which provides greater time for
the pesticide to enter the targets surface. These are used during high temperature, low
humidity and low spray volume situations.
Deposition Aid:
Reduces the amount of fine spray particles that carry pesticide out of target areas. It
Reduces evaporation of the spray droplet; Used during high temperature, low
humidity and low spray volume situations.
Compatibility Agents: Compounds that aid in stability and dispersion of various
pesticide formulations and spray carrier mixtures.
Colorants: Used to alter the color of spray solutions.

Pesticide formulation

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