Illinois Pesticide Applicator Exam
Comprehensive Resource To Help You Ace 2026-2027
Exams Includes Frequently Tested Questions With
ELABORATED 100% Correct COMPLETE SOLUTIONS
Guaranteed Pass First Attempt!! Current Update!!
1. What are the five steps one should follow when mixing multiple pesticides
in the same spray tank? - Correct Answer: Assess pesticide
compatibility, read label contents, consult technical staff
(specialists/manufacturer), perform a jar compatibility test, and add/mix
products one at a time in the appropriate order
2. When are pesticides considered to be compatible? - Correct Answer:
When they can be safely mixed and applied in combination without
unfavorably affecting toxicity, physical properties, or plant safety
3. Define chemical incompatibility - Correct Answer: Altered activity of one
or more of the pesticides mixed together in a spray tank
4. Define physical incompatibility - Correct Answer: Pesticides cannot be
physically mixed together; incompatible mixtures may settle, layer, curdle,
or gel
,5. What may cause physical incompatibility between pesticides? - Correct
Answer: pH, chemical composition, and/or temperature of container
6. Define synergism - Correct Answer: Increased activity or effectiveness as
opposed to applying the products separately
7. Define antagonism - Correct Answer: Decreased activity or effectiveness
as opposed to applying the products separately
8. Who is responsible for a failed tank-mix when the labels provide no
guidance? - Correct Answer: The user
9. When should a jar compatibility test be conducted? - Correct Answer:
When physical compatibility is a concern
10.How do you know the suggested mixing order? - Correct Answer: The
product label
11.What three characteristics create useful pest control? - Correct Answer:
Selectivity, mobility, and residual activity
12.Define selective pesticides - Correct Answer: Control some related
pests, but not others
,13.Define non-selective pesticides - Correct Answer: Control all related
pests
14.Define pest resurgence - Correct Answer: A situation in which a pest
population, after having been suppressed, rebounds to numbers higher
than before suppression occurred
15.What causes suppressed pest populations to rebound to populations
greater than before? - Correct Answer: Lack of beneficial predators and
parasites
16.Define contact pesticides - Correct Answer: Do not move within the
plant; effective only where applied (local surface)
17.Define systemic pesticides - Correct Answer: Move within the plant;
often effective against pests or plant parts that your application methods
can't reach, not always completely systemic
18.Define residual pesticides - Correct Answer: Remain sufficiently active
to kill pests for several days, weeks, or months after application; may
reduce the need for retreatment and/or adversely affect non-target species
19.Define nonresidual pesticides - Correct Answer: After application, they
rapidly break down into products that are ineffective at controlling pests; in
most cases, it is better to use a less persistent pesticide and plan for
necessary treatment
, 20.Define pesticide tolerance - Correct Answer: The amount of pesticide
residue that may legally remain in or on a food for feed crop when it is
harvested
21.What happens if residues on an unlabeled pesticide are found or if the level
of a labeled pesticide is too high? - Correct Answer: Product can be
seized and fines can be imposed
22.Define preharvest interval (PHI) - Correct Answer: The minimum length
of time that must pass between pesticide application and crop
treatment/harvest
23.Where are preharvest intervals (PHIs) found? - Correct Answer: Food-
crop pesticide labels
24.What are the three major types of applications? - Correct Answer: Spot,
band, and broadcast
25.Define spot applications - Correct Answer: Treat only a portion of the
total area; used to control pests that are grouped/clustered
26.Define band applications - Correct Answer: Treat only a narrow strip
over or alongside a row of desirable plants
Comprehensive Resource To Help You Ace 2026-2027
Exams Includes Frequently Tested Questions With
ELABORATED 100% Correct COMPLETE SOLUTIONS
Guaranteed Pass First Attempt!! Current Update!!
1. What are the five steps one should follow when mixing multiple pesticides
in the same spray tank? - Correct Answer: Assess pesticide
compatibility, read label contents, consult technical staff
(specialists/manufacturer), perform a jar compatibility test, and add/mix
products one at a time in the appropriate order
2. When are pesticides considered to be compatible? - Correct Answer:
When they can be safely mixed and applied in combination without
unfavorably affecting toxicity, physical properties, or plant safety
3. Define chemical incompatibility - Correct Answer: Altered activity of one
or more of the pesticides mixed together in a spray tank
4. Define physical incompatibility - Correct Answer: Pesticides cannot be
physically mixed together; incompatible mixtures may settle, layer, curdle,
or gel
,5. What may cause physical incompatibility between pesticides? - Correct
Answer: pH, chemical composition, and/or temperature of container
6. Define synergism - Correct Answer: Increased activity or effectiveness as
opposed to applying the products separately
7. Define antagonism - Correct Answer: Decreased activity or effectiveness
as opposed to applying the products separately
8. Who is responsible for a failed tank-mix when the labels provide no
guidance? - Correct Answer: The user
9. When should a jar compatibility test be conducted? - Correct Answer:
When physical compatibility is a concern
10.How do you know the suggested mixing order? - Correct Answer: The
product label
11.What three characteristics create useful pest control? - Correct Answer:
Selectivity, mobility, and residual activity
12.Define selective pesticides - Correct Answer: Control some related
pests, but not others
,13.Define non-selective pesticides - Correct Answer: Control all related
pests
14.Define pest resurgence - Correct Answer: A situation in which a pest
population, after having been suppressed, rebounds to numbers higher
than before suppression occurred
15.What causes suppressed pest populations to rebound to populations
greater than before? - Correct Answer: Lack of beneficial predators and
parasites
16.Define contact pesticides - Correct Answer: Do not move within the
plant; effective only where applied (local surface)
17.Define systemic pesticides - Correct Answer: Move within the plant;
often effective against pests or plant parts that your application methods
can't reach, not always completely systemic
18.Define residual pesticides - Correct Answer: Remain sufficiently active
to kill pests for several days, weeks, or months after application; may
reduce the need for retreatment and/or adversely affect non-target species
19.Define nonresidual pesticides - Correct Answer: After application, they
rapidly break down into products that are ineffective at controlling pests; in
most cases, it is better to use a less persistent pesticide and plan for
necessary treatment
, 20.Define pesticide tolerance - Correct Answer: The amount of pesticide
residue that may legally remain in or on a food for feed crop when it is
harvested
21.What happens if residues on an unlabeled pesticide are found or if the level
of a labeled pesticide is too high? - Correct Answer: Product can be
seized and fines can be imposed
22.Define preharvest interval (PHI) - Correct Answer: The minimum length
of time that must pass between pesticide application and crop
treatment/harvest
23.Where are preharvest intervals (PHIs) found? - Correct Answer: Food-
crop pesticide labels
24.What are the three major types of applications? - Correct Answer: Spot,
band, and broadcast
25.Define spot applications - Correct Answer: Treat only a portion of the
total area; used to control pests that are grouped/clustered
26.Define band applications - Correct Answer: Treat only a narrow strip
over or alongside a row of desirable plants
