Helena Chemical ::Product::

These are the obvious What? Why? When? Where? Who? How? Questions. These questions can apply to either the scientific or commercial aspects of adjuvants. The answers to the commercial aspects will be partly answered in this manuscript, the answers to the scientific aspects will be deferred to appropriate reference materials. Terminology, classification and chemistry, the historical use of adjuvants, the action of adjuvants on plants and soils, the toxicology of adjuvants and other pertinent information can be found in Adjuvants for Herbicides.

The modes of action and physiological basis of adjuvants, a historical overview, recent developments, a bibliography of agro–adjuvants and several important discussions on application can be found in Adjuvants for Agrochemicals. This book represents the Proceedings of the Second International Symposium on Adjuvants for Agrochemicals. Pesticide Science, contains many of the manuscripts presented at the Third International Symposium on Adjuvants for Agrochemicals. This includes manuscripts on biological effects, pesticide applications, predictive modeling of adjuvant activities, penetration, translocation, activation and other functions. Also included are manuscripts on the structure and chemistry of plant cuticles, the role of surfactants and solvents in pesticide formulations, the use of new types including the organosilicone and fertilizer based adjuvants, the antagonistic effects of certain components, the use of adjuvants with pesticides other than herbicides and modes of action. Manuscripts also deta

The Proceedings of the Fifth International Symposium on Adjuvants for Agrochemicals, contain many manuscripts detailing adjuvant physical/chemical properties, methodology, mechanism of action, and regulatory and registration requirements. Also included are manuscripts on biological performance, drift management, spray application and the effects biotechnology could have on the agrochemical and adjuvant market.

The labels of many of the agrochemicals distributed in the U.S. are detailed in the Crop Protection Reference, and Turf and Ornamental Reference. Also included are labels of many adjuvant products. The adjuvant recommendations and requirements contained on the Environmental Protection Agency (EPA) agrochemical labels form the basis for much of the adjuvant market in the U.S. A review of the most commonly used agrochemical labels reveal that over 200 labels require the use of one or more adjuvants. And, eighteen or more different types are recommended. In addition, other types can be used if the agrochemical label does not specifically prohibit the addition of an adjuvant. From these reference sources – and the many other detailed in the “LITERATURE CITED” sections of each manuscript in each reference - one can see there is an abundance of technical and/or scientific information available to answer those types of questions. The answers to commercial questions are much more elusive.

2. What is the basis for my need to know about adjuvants?<TOP>

There are several definitions of “adjuvants” and the ISAA 2001 organizing committee defines adjuvant as being “a substance without significant pesticide properties, added to an agrochemical to add or modify the activity of the agrochemical”. If one is in the agrochemical industry in the U.S., the need for adjuvants or adjuvant information will occur.

In the U.S., over 200 Environmental Protection Agency (EPA) registered agrochemicals have very specific recommendations in their labels for the use of one or more adjuvants. These recommendations are for eighteen or more different types. Different types of adjuvants are recommended for one or more of the following reasons: to help maximize agrochemical efficacy, to help maximize spray application efficiency, to help minimize legal consequences, or any combination of the three. The consistent effective results from the use of adjuvants will depend upon selecting the correct type of adjuvant for use with a specific agrochemical and then the best suited product within the type, then using that adjuvant at the correct rate.

3. Why is adjuvant terminology so important?<TOP>

Much of the lack of understanding and/or confusion about adjuvants comes from the
lack of understanding of the importance of adjuvant terminology. Many people use the
terms “adjuvants” and “surfactants” interchangeably. Although this can refer to the
same product, it should be remembered that all surfactants are adjuvants, but not all
adjuvants are surfactants. A review of a glossary in some recent publications will
provide the current approved terminology for the most commonly used adjuvants.
Understanding adjuvant terminology helps obtain the optimum agrochemical
performance. Knowing the differences among a “crop oil concentrate”, a “crop oil”, or
an “oil” will let you know why an agrochemical label makes a specific recommendation
for one, but not the others. Another example of the importance of understanding the
terminology is the fact that agrochemical activity in combination with a “nonionic
surfactant” can be tremendously different than in a combination of just a “surfactant”
that could be anionic, cationic or amphoteric.

4. Why are there so many adjuvant types?<TOP>

A review of EPA registered agrochemical labels reveals the need for many different
types of adjuvants. The most common types are crop oil concentrates, nonionic
surfactants, wetters, super-wetters, spreaders, stickers, spreaders – stickers, deposition
agents, drift control agents, compatibility agents, buffering agents, antifoaming agents,
defoaming agents, activators, marking agents, fertilizer based adjuvants, and others. A
recent review of agrochemical labels reveals recommendations for at least eighteen
different types. Some agrochemicals have recommendation for more than one type –
sometimes as many as eight – especially when one considers tank mixes. The labels
may require different adjuvant types when used in different types of application
equipment, on different crops, under different environmental conditions, in different
geographical places, or in different tank mixes. This is one reason one cannot buy and
use just one adjuvant for all applications. So, the reason there are so many different
types is because there are so many needs for different functions for maximum
agrochemical effectiveness, for crop safety and spray application efficiency.

5. Why are there differences between products within adjuvant types?<TOP>

Once the correct adjuvant type has been determined by reading the agrochemical label,
it is equally important to select the right product within the type. The importance of
doing this is illustrated by the following example. Organophosphate insecticides are a
type of insecticide. Both parathion and malathion are organophosphates. Parathion is
considerably more toxic than malathion. Notice the range of activity within the type!
That same “range of activity” exists between products within each type of adjuvant.
Some of the reasons for this include: the type and amounts of active ingredients, the
type and amount of emulsifiers, the purity of emulsifiers and active ingredients, the
addition of non – surfactant components, the addition of “fillers”, the type of oil
components and the viscosity of them, the refinement of the oil, the ionic classification
of the total mixture, the addition of fertilizer components, the ratios of all components
and others. These factors are also responsible for the difference in costs between
adjuvant types and between products within adjuvant types.

6. Why is there so much emphasis on “spray application” at agrochemical and adjuvant meetings?<TOP>

Spray application is perhaps the weakest link in the chain of events an agrochemical
follows through its discovery, synthesis, research, development, field testing, labeling,
registration and final use. It is often the final human controllable event in most spray
programs. Some researchers have claimed that 25 – 50 even 75% of the effectiveness of
an agrochemical can be dependent on spray application. It is not hard to think of
examples where 100% effectiveness can be attributed to spray application. The reason
spray application has such an effect on agrochemical effectiveness is better understood
when one examines agrochemical characteristics such as incompatibility, stability,
solubility, suspension, foaming, drift, impingement, evaporation, volatilization,
degradation, adherence, absorption, penetration, translocation, surface tension, ultra
violet degradation, coverage and others. Many of spray application problems created by
these agrochemical characteristics are visible to the applicator (i.e. foaming, physical
incompatibility) and appropriate adjuvants are added to alleviate the problems.
However, some problems are not visible to the applicator (i.e. chemical incompatibility,
degradation, evaporation) but may in fact have an even greater influence on
agrochemical efficacy than those that are. Researchers have well documented that these
(and other) problems do exist and do have negative effects on agrochemical
effectiveness and that certain adjuvants can be used as corrective measures to help offset
their negative effects.

7. What is the relationship among adjuvants, spray application and agrochemicals?<TOP>

Adjuvants help reduce, minimize or eliminate spray application problems. They do this because they are designed to perform specific functions. These functions include wetting, spreading, sticking, penetrating, activating, deposition, reducing “bounce – off”, reducing evaporation, buffering, conditioning, emulsifying, dispersing, suspending, reducing spray drift, preventing foaming, eliminating foam, marking sprayed areas and others. No single adjuvant can perform all adjuvant functions. However, different compatible adjuvants can be combined to perform multiple functions simultaneously. The actions between adjuvants and spray application can have a very positive effect on agrochemical activity. In addition, certain adjuvants can have a synergistic effect with the agrochemical itself.

8. How are different types of adjuvants formed?<TOP>

Agrochemical labels require many different types of adjuvants. Although some typesare similar in some respects, these are major differences in composition and activities in others. These differences are what provide the different functions required by different agrochemicals and spray applications. Different types of surfactants are formed by chemical modifications to the two parts comprising the surfactants molecule, the hydrocarbon group (tail) and the water soluble group (head). The chemical modifications can be made to either component, or to both. In addition other nonsurfactant components can be added. By making these modifications and/or additions adjuvant types as diverse as nonionic surfactants, crop oil concentrates, stickers, drift control agents, compatibility agents and other adjuvants are formed.

9. What rate of adjuvant should I use?<TOP>

Once the adjuvant type has been determined and then the best suited product within the type, then the use rate must be determined. Unlike most agrochemicals whose rates are based on a rate/hectare basis, most adjuvant rates are based on a volume/volume (v/v) basis. An exception to this is the newer fertilizer based adjuvants whose rates have been established or a rate/hectare basis. The agrochemical label will generally provide the information as to the appropriate rate of adjuvant for a specific use on a specific crop. In general, most nonionic surfactants will be recommended for most uses on most crops at a .25 - .50% v/v basis. Crop oil concentrates will be recommended at a 1% v/v concentration. Other types of adjuvants vary from a .125% v/v to a 3% v/v concentration rate. In some cases, the agrochemical label will direct the user to the adjuvant label for the rate to use in a specific situation. To avoid legal issues, always try to use a rate specified by the agrochemical label.

10. Where does one get the commercial information needed about using adjuvants with agrochemicals?<TOP>

In the U.S., the need for adjuvants is for the most part, determined by the requirements,
recommendations or suggestions of basic manufacturer’s agrochemical label
information. A review of agrochemical labeling reveals adjuvant information falling
into several different categories. Labels can require, recommend, suggest or prohibit the
use of adjuvants. Labels can be entirely void of adjuvant information, and labels can
contain a combination of all of the above information. Many labels are labeled for use
in a tank mix with other agrochemicals. In this situation, the agrochemical label with
the most restrictive labeling takes precedence. Although this information can be
confusing, it is critical to the adjuvant industry in the U.S. for it to be understood. In the
U.S., all EPA labels have a statement that reads “It is a violation of federal law to use
this product in any manner inconsistent with its labeling”. Adjuvant usage in conflict
with the label can constitute such a violation. In addition, all EPA labels have a
manufacturer’s conditions of sale, warranty or limited warranty printed on the label.
This information states that the product must be used “exactly” as the label says, or the
manufacturer is not responsible for any nonperformance, crop injury or any other
problems. Again, adjuvant usage different from label information can void the
warranty. Adjuvant labels are another source of information, but care must be taken
before using. Adjuvants themselves are not regulated or registered with the EPA, as are
the agrochemicals with which they are used. Other sources of information can be found
on agrochemical technical data sheets, technical literature, material safety data sheets
(MSDS), supplemental labels, product guides, label books and promotional literature.
In most cases, any printed information from a basic manufacturer about an agrochemical
can be viewed as an extension of the EPA label. To be sure, always refer to the label on
the agrochemical product for the most protective information. And, the local company
representative of the adjuvant product should have the basic and other pertinent
information on the adjuvant, agrochemical, application and agronomics.

11. If agrochemicals require adjuvants to work, then why do not the basic manufacturers of agrochemicals formulate them into their agrochemical formulations to begin with?<TOP>

This is one of the most basic commercial questions. If we cannot answer this question emphatically, the entire adjuvant industry would exist in an even more hostile/fragile environment. However, we can emphatically answer this question with the following information. Basic manufacturers (basics) of agrochemicals do not want to build adjuvants – per se – into their formulations of active ingredients. By most definitions, if they did that it would all be a mute issue since the “adjuvant” would then be an “inert” and that would be a topic for an entirely different symposium. What the basic wants is to build adjuvant functions into his formulation. The basic must consider the following information when making the decision.
a. Unlike most agrochemicals that work on a rate per hectare basis, most adjuvants work on a dilution ratio, or a volume/volume (v/v) basis. Therefore, the correct amount of “adjuvant” to “build in” could never be predetermined by the basic since the carrier application volume may vary from as little as 1 liter per hectare to as much as 14,025 liters per hectare.
b. EPA registered agrochemical labels require eighteen or more different types of adjuvants. Most individual labels only require one, two or three different adjuvants, but in tank mixes those could change to one, two or three – sometimes as many as eight – different adjuvants. There simply is not enough room in the agrochemical formulation to allow for the volume to meet all the requirements.
c. Different carriers (diluents) sometimes require different types and rates of adjuvants. Common carriers include water, liquid fertilizers, petroleum oil, vegetable oils, mixtures of some of the above, and then some granules. All the necessary different types – and amounts – of adjuvants could not be predetermined and formulated into the agrochemical active ingredient formulation.
d. Different crops sometime require different types of adjuvants. Some crops are oil sensitive, some not. Some crops are hard to wet, some not. A basic would not want to build in “adjuvants” and limit his agrochemical for use on only one type of crop. e. Adjuvants “built in” to agrochemical formulations would add costs to the basics product for all users, not just the ones requiring the use of a specific adjuvant for a specific purpose.
f. Different application methods can require different types of adjuvants. Some methods are conducive to drift (i.e., aerial, high-pressure ground sprays) and a drift control agent is required. But, the same agrochemical may not drift under other types of application (i.e., low pressure, high volume ground application, rope wick applications) or under certain environmental conditions. A basic would not want to build a drift control adjuvant into his agrochemical and have the cost added to all his product when only a percentage is applied in application methods or under environmental conditions conducive to drift.
g. The components of certain adjuvants (or inerts) can degrade certain agrochemical active ingredients or can degrade themselves after prolonged storage.
h. Building in “adjuvants” would increase the “bulk” of agrochemical formulations. This could create a higher use rate, larger container sizes, more freight, more storage space, more handling and other problems. With the trend towards “grams per hectare” chemistry, this would not be an appropriate action.
i. It is a violation of federal law not to use specific adjuvants with some agrochemicals in some uses, but it is also a violation of federal law to use any adjuvant with that same agrochemical in other uses. Formulation of the adjuvant into the agrochemical would exclude that product’s use in those situations.
j. Some agrochemicals, when used alone, require a specific type adjuvant to increase the biological effect on some pests. When tank mixed with other agrochemicals, its label specifically prohibits the addition of any adjuvant. This could be to prevent crop injury, or defer liability or for other reasons. Formulating the “adjuvant” into the agrochemical would limit its market with tank mixes. The trend is towards more tank mixes, so most basics would not want to limit their market share.
k. Some agrochemicals do not need an adjuvant to increase bio efficacy. They do need one to reduce, minimize or eliminate foaming, compatibility problems, or drift. Or they need one to improve deposition, coverage, penetration, etc. under certain environmental conditions. Under these uses, the adjuvant is used to improve the application, not bio efficacy. Building in the “adjuvant” would add costs to all applications whether needed or not.
l. Many agrochemical companies are basic in agrochemical active ingredient production, but not basic in adjuvant production. They may have access to some adjuvant components, but not all. And, their in-house adjuvant chemistry may not be the type needed to complement their agrochemical chemistry. They do not want to add to their cost by buying components from a competitor, so they write their label to allow their distributors/dealers to supply their product’s adjuvant needs.
m. Recent trends show basics going to highly concentrated, low rate formulations of agrochemicals. This sometimes precludes the addition of an “adjuvant package” within the formulation.
n. Some states/crops/agrochemicals have geographical restrictions on the use/non-use of agrochemicals, and adjuvants. Basics would have to maintain multiple inventories, labels and registrations.
o. Many basics market “dry” formulations of agrochemicals. These can be packaged in water soluble film packages. This can preclude the addition of oil based adjuvants, fertilizer based adjuvants and other adjuvant technologies.
p. Some basics’ product line requires several different types of adjuvant products. The basic would probably have to source some from competitors and maintain an inventory of all required products.
q. Basics’ core business is generally the discovery, synthesis, manufacturing and sales and marketing of agrochemical active ingredients. It is well known that certain adjuvants can help certain agrochemicals perform at the lowest labeled rate, or even below label rates. Some basics are not economically driven to formulate “adjuvants” into their agrochemical formulations creating a situation that would reduce the sales of their core products.
r. It is ultimately easier and more convenient for the basic to optimize the formulation his agrochemical product for the dominate market position, then let the adjuvant formulators/distributors optimize the formulations of their adjuvant products to cover the exceptions.
s. Many of the reasons listed above are the same reasons basics cannot effectively copackage adjuvants with agrochemicals.

12. What is the best adjuvant to use with glyphosate?<TOP>

This could be the most frequently asked question. Generally it is asked about
glyphosate, but in certain areas could be asked about atrazine, or 2,4-D, or any other
agrochemical. But, probably glyphosate! And the most common answer seems to be
that “more glyphosate” is the best “adjuvant” for glyphosate. But, we need to question
that answer.
Glyphosate is one of the most widely used herbicides in the world. Several different
formulations are available in most countries and in many cases there are “fully loaded”,
“half loaded” and “non loaded” formulations. “Loaded” indicating the amount of
surfactants/emulsifiers/inerts contained in the formulated product. The question is
directed at those formulations whose labels recommend or require an adjuvant.
Before we even begin to answer the question, we have to ask even more questions.
What formulation of glyphosate? In the U.S. there are already over 10 formulations and
the patent has just recently expired (2000). In other countries where the patent expired
earlier even more formulations exist. In addition, there are hundreds of tank mix
options with the range of glyphosate formulations. So, what is the one, two or three or
more tank mix partners with the application? And what type of application? Air?
Ground? What is the carrier or diluent? Water? Oil? Fertilizer? And the spray
volume? Ultra low? Low? Medium? High? And, what about the environmental
conditions? Arid? Hot and humid? Forecast for rain? And what is the pest? Weeds?
Grasses? Weeds and grasses? Insects, too? And what growth stage is the pest in?
Juvenile? Actively growing? Mature? And the tank mix partners? How many?
Contact? Systemic? Both? And the surrounding or near by crops? Are they transgenic
or conventional? And their growth stage? And, what are the economic values of the
crops? Low? Medium? High value? As one can see the list of questions we need to
ask before we begin to answer is lengthy. From the commercial point of view we can
definitely say that the best adjuvant for use with glyphosate is absolutely not more
glyphosate! Because the price of glyphosate has been lowered so much, many
commercial, extension, research, academic, consultants and other persons just take the
easy way out and say “the best (or cheapest) adjuvant for glyphosate is more
glyphosate!” But, consider the following. No matter how much glyphosate you add it
cannot improve the compatibility with the carrier, diluent or other tank mix partners.
And, it cannot decrease the foaming problems, or keep it from drifting to a susceptible
crop, or improve coverage, or add other adjuvant functions required by the EPA
registered tank mix partners, or in some cases its own label; or provide the synergism of
adding fertilizer based adjuvants, or help in the weed resistance management programs,
or reduce the antagonism of other tank mix partners. And from a stewardship position,
is not the goal to reduce the pounds of agrochemical active ingredients applied into the
environment? So, when somebody tells you the best adjuvant for use with glyphosate is
“more glyphosate”, you need to rephrase the question so you can get the correct
answers.

13. Can modifying spray application equipment replace the need for adding adjuvants?<TOP>

This, or a variation of it, is another frequently asked question. If you listen to certain
spray equipment manufacturers, that is all you need to do. Modifying spray equipment
can help improve spray application. By altering the nozzle type, nozzle configurations,
nozzle size, boom height, pump pressure, by adding air, putting on shields, adding
electrical "charges" and changing other equipment variables you can effectively alter
droplet size and therefore affect spray application. But most equipment modifications
can only get you smaller droplets or larger droplets. Smaller droplets give better
coverage but are prone to drift or evaporate. Larger droplets give better deposition and
can decrease drift but can also bounce off the foliage and reduce coverage and
bioefficacy. So, no matter what adjustments you make to spray application equipment,
they will never replace the need for adjuvants.
Modifying spray equipment cannot fulfill any of the EPA agrochemical label
requirements for the addition of 18 or more different types of adjuvants. These are legal
requirements and are required for liability and warranty protection. Modifying
equipment cannot create a synergistic effect with agrochemical actives like crop oil
concentrates, nonionic surfactants, fertilizer based adjuvants or other adjuvants can.
And modifying application equipment cannot improve the compatibility of many
different tank mix partners in water, fertilizer or oil. And modifying equipment cannot
decrease foaming problems, cannot buffer a spray solution or otherwise “condition” the
carrier or diluent. It cannot increase the penetration of the spray solution or spray
deposit into the cuticles of leaves or the stems of plants. And, it cannot assist in the
translocation of agrochemical active ingredients throughout the plant. Likewise, it
cannot decrease the evaporation of a spray deposit, or keep the spray deposit from
washing off the plant surface by rain, irrigation or dew. Nor, can it mark a sprayed area.
Modifying spray application equipment simply cannot fulfill all the functions required
by agrochemical labels or by agrochemical applications for maximum effectiveness.
So, for optimum spray application effects, it is probably fair to say it is going to require
certain modifications of the equipment plus the addition of one or more appropriate
adjuvants.

14. Can the use of fertilizers replace the need for adjuvants?<TOP>

Many users of agrochemicals add fertilizer to the spray solution for any number of
reasons. These reasons include the low cost, the ready availability, the desire to “weed
and feed” in a single application, the desire to “heat up” a treatment, or speed up the
results, or other reasons. Some users feel that by adding fertilizer, the need for other
adjuvants is not required. However, consider the following. Adding fertilizer to some
agrochemical applications can result in some beneficial effects. In fact, some
agrochemical labels require the addition of fertilizers and some require the addition of
fertilizers in combination with adjuvants. In these cases, the type and amount of
fertilizer is generally detailed on the agrochemical label. But in many other cases, the
addition of fertilizer as a substitute for adjuvants is not a good idea. Some users think
that adding fertilizer replaces the need for a nonionic surfactant commonly used for
wetting, spreading or general coverage. The use of fertilizer in this situation can cause
the user to be disappointed in the results. Fertilizers generally do not have surfactant
properties and do not contain surfactants or emulsifiers that help provide coverage. This
can be demonstrated by noting the phyto characteristics of fertilizer based applications.
In most cases, the phytotoxity, or burn, is in spots on the leaf or in streaks along the leaf
edges. If fertilizer was good at providing coverage, that damage would be uniformly
spread over the leaf surface. For those agrochemicals recommending or requiring the
use of fertilizer – primarily some post-applied herbicides – those labels require a
specific type, i.e. ammonium nitrogen fertilizer such as 28-0-0, 30-0-0 or 10-34-0, or
spray grade ammonium sulfate (AMS - 21-0-0). Problems can arise when users
substitute other forms or qualities of nitrogen or by adding fertilizers with phosphorus,
potassium and/or micro and secondary nutrient components. If the user is sourcing
fertilizers from on-site storage, he may be using different grades of fertilizer, different
qualities and fertilizers that have been contaminated by other substances in hauling,
transfer or storage. So, the use of fertilizer to replace adjuvants should be carefully
considered to make sure that the agrochemical or tank mix partners labels do allow the
use, and if so, to follow the requirements for type and quality. Then compatibility of the
fertilizer with the tank mix solution and the resulting biological efficacy and crop
response should be evaluated. The ionic classification and pH of the fertilizer should be
considered so as to not cause liability and/or label warranty issues. And, many
agrochemical labels require specific types and amounts of certain adjuvants –
sometimes in addition to fertilizers – so it is important not to create liability or nonperformance
situations by leaving them out. And, one should consider the abrasive and
corrosive effects of certain fertilizers when used with certain types of spray equipment.
Also, the use of certain fertilizers can result in antagonistic effects with certain
agrochemical actives causing them to be inactivated. So, like some of the answers to
the other questions, the addition of fertilizer to some agrochemical applications is a
needed and useful application, but just adding fertilizer and leaving out the other
required adjuvants can result in several violations of the label and can result in
variability in biological activity and crop response.

15. Can adjuvants allow for lower use rates of agrochemical active ingredients?<TOP>

The short answer to this question is “Yes. No. And Maybe!” You do not have to add an
adjuvant to use lower rates of agrochemical active ingredients. Many growers,
applicators and other users are already using lower rates without adding anything. They
are doing it based on university extension research results, demonstrations, consultants’
advise, for economic or other reasons. So part of the answer is, if you are already using
lower rates without adding an adjuvant, then, at least, try an adjuvant with the lower rate
as a comparison. Rates on most agrochemical labels are determined by research and
development. You should consistently get good to excellent results when you use the
recommended rate. But on many labels you are given a rate range. If you are going to
lower your rate, start by lowering it to another rate within the labeled range. Some users
actually use agrochemicals below label rates and use adjuvants to improve the efficacy
of those lower rates back up to that of labeled rates. They choose to do this on their
own, for economic reasons or have seen data from basics, research, extension,
consultants or commercial companies or others that gave them the idea. This data exists
for many agrochemical and adjuvant products since most adjuvant research is done
using agrochemical rates below label rates. This is done to determine the adjuvant
effects without being overpowered by the agrochemical effects. Generally speaking, it
seems that growers having better overall agronomic practices benefit most from using
lower rates of agrochemicals. They have already done a good job in eliminating several
limiting factors of production, so the lower rates are more effective. So rather than
experimenting with lower agrochemical rates, or adding adjuvants to lower
agrochemical rates, make sure the user is doing the best job possible in all other
agronomic practices. In any case, nobody in the agrochemical or adjuvant industry
should recommend any agrochemical below its labeled recommendation unless they are
fully aware of the legal, liability, pest management resistance issues and other warranty
consequences.

16. In the U.S., why are adjuvant use rates generally higher than for other countries?<TOP>

In the U.S., nonionic surfactants are generally recommended at .25-.50%
volume/volume (v/v) concentration. In many other countries nonionic surfactant use
rates are .05-.1% v/v concentration. In the U.S., crop oil concentrates are generally used
at 1% v/v, in other countries at .2-.375% v/v concentrations. Historically, adjuvant use
rates – particularly surfactants - have been determined by critical micelle concentration
(CMC) values. Biologically, surfactant use rates have been determined by rate screens
that showed a break-point in specific biological responses. In the U.S. the basic
manufacturers and users shifted to the higher use rates where biological activity was
optimized and/or where functions other than simple spreading or wetting were desired.
Many countries continue to make adjuvant spray application rates based on CMC values
since they are only looking for the spreading/wetting functions, the coverage functions
or for economical reasons.
Also, adjuvants are not as heavily regulated in the U.S. as in many other countries. This
allows adjuvant manufacturers and users to choose a wider rate range than allowed in
other countries.

17. If the basic manufacturers of agrochemicals require the use of adjuvants with their products, then why do not they sell adjuvants as a part of their own product line?<TOP>

Some basic manufacturers do sell adjuvants as part of their product line. Not as many in the U.S. as in other countries, but many do have their own adjuvant products for sale. These companies include Rohm and Haas, Valent, DuPont, Syngenta, Bayer, Monsanto, Dow AgroSciences, BASF and others. However, most basics do not sell adjuvants as part of their product line in the U.S. for one or more of the following reasons.
a. The adjuvant market is not big enough to have the critical mass to support a basic’s investment in research and development or sales and marketing activities. Consider the size of the U.S. agrochemical market at about 7.3 billion U.S. dollars versus the U.S. adjuvant market at about $400 million. A basic with a 10% market share of agrochemicals would not be impressed with a 10% market share of adjuvants.
b. Generally speaking, there is very little intellectual property protection on adjuvants and basics are not interested in marketing unprotected products.
c. To be effective, a basic would almost have to market the complete line of adjuvants required by its agrochemical labels for use above, with all EPA registered tank mixes.
d. Adjuvants are not a basic’s core business and many times the best adjuvant chemistry for their agrochemical chemistry has to be purchased from a competitor.
e. And, most adjuvant products are from local, regional or national formulators/distributors. If a basic marketed its own line it would be in direct competition with its own customers.
f. In addition, most basics are discovery, synthesis, research, development and registration driven. The management of adjuvants, which do not require EPA registrations, does not fit into their corporate culture.
g. Some basics feel that adjuvants could be used to lower the rates of agrochemical active ingredients, a situation generally not encouraged or supported.