Oklahoma Commercial Pesticide
Applicator Exam Category 3:
Ornamental And Turf Pest Control
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. Which is the most important first step in an Integrated Pest Management
(IPM) program for turf?
A. Apply preventive insecticide
B. Identify the pest correctly
C. Increase irrigation frequency
D. Mix herbicides for broad control
Correct Answer: B
Rationale: Correct pest identification is the foundation of IPM because all control
decisions depend on knowing the exact organism causing damage.
Misidentification can lead to ineffective or unnecessary pesticide applications,
increased resistance, and environmental harm. Proper diagnosis also helps
determine pest life cycle stage, thresholds, and appropriate cultural or chemical
controls. Without accurate identification, no other IPM component can be
correctly applied.
2. Which pesticide formulation is most likely to be absorbed through plant
foliage?
, A. Granular
B. Bait
C. Emulsifiable concentrate
D. Fumigant
Correct Answer: C
Rationale: Emulsifiable concentrates (ECs) are formulated to mix with water and
spread evenly on plant surfaces, allowing better foliar penetration. They often
contain solvents and surfactants that enhance absorption through waxy cuticles.
Granular and bait formulations rely on soil or ingestion activity, while fumigants
act as gases in enclosed spaces. ECs are widely used for ornamental and turf
foliar pest control due to their effectiveness in contact and systemic uptake.
3. What is the main purpose of a pesticide label?
A. Suggest marketing strategies
B. Provide legal use directions
C. List competitor products
D. Describe plant diseases only
Correct Answer: A
Rationale: The pesticide label is the legal document that defines how a product
may be used. It includes application rates, target pests, safety precautions,
environmental hazards, and restrictions. It is enforceable by law and must be
strictly followed. Ignoring label instructions is a violation of federal pesticide
regulations. Labels are not marketing tools but binding legal documents that
ensure safe and effective use.
4. Which pest is most commonly associated with irregular brown patches in
turfgrass caused by fungal infection?
A. White grubs
B. Dollar spot
, C. Aphids
D. Cutworms
Correct Answer: B
Rationale: Dollar spot is a common turf fungal disease characterized by small,
circular, straw-colored patches. It thrives in humid conditions with low nitrogen
levels. Unlike insect pests such as grubs or aphids, dollar spot is a pathogen that
affects leaf tissue. Early detection and proper fungicide rotation, along with
cultural practices like balanced fertilization, help control its spread effectively.
5. What is the primary function of surfactants in pesticide mixtures?
A. Increase vapor pressure
B. Improve spray coverage
C. Kill insects directly
D. Reduce plant growth
Correct Answer: B
Rationale: Surfactants improve the spreading, wetting, and sticking of spray
solutions on plant surfaces. They reduce surface tension, allowing droplets to
cover leaves more evenly and enhance pesticide effectiveness. Surfactants do
not kill pests directly but significantly increase the efficiency of active
ingredients. They are especially useful in ornamental and turf applications
where waxy leaf surfaces can repel sprays.
6. Which soil type generally requires the highest pesticide application rate due
to adsorption?
A. Sandy soil
B. Loam soil
C. Organic peat soil
D. Clay soil
Correct Answer: D
, Rationale: Clay soils have high cation exchange capacity and large surface area,
which increases pesticide adsorption. This binding reduces pesticide availability,
often requiring higher application rates compared to sandy soils. However,
careful calibration is essential to avoid environmental contamination. Sandy
soils, in contrast, allow faster movement and leaching, often requiring lower but
more frequent applications.
7. What is the primary symptom of iron chlorosis in ornamental plants?
A. Dark green leaves
B. Yellowing between leaf veins
C. Holes in leaves
D. Wilting stems
Correct Answer: C
Rationale: Iron chlorosis typically causes interveinal yellowing, where leaf tissue
turns yellow while veins remain green. It is often caused by high soil pH, poor
iron availability, or root stress. Although leaf holes or wilting may indicate insect
or water stress, chlorosis is a nutrient disorder affecting chlorophyll production.
Proper soil amendment or foliar iron applications are common corrective
measures.
8. What is the most effective method to prevent pesticide resistance?
A. Increase dosage regularly
B. Rotate pesticide modes of action
C. Use only one pesticide
D. Apply more frequently
Correct Answer: D
Rationale: Rotating pesticides with different modes of action reduces selection
pressure on pest populations, preventing resistant individuals from dominating.
Overuse of a single chemical group accelerates resistance development.
Applicator Exam Category 3:
Ornamental And Turf Pest Control
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. Which is the most important first step in an Integrated Pest Management
(IPM) program for turf?
A. Apply preventive insecticide
B. Identify the pest correctly
C. Increase irrigation frequency
D. Mix herbicides for broad control
Correct Answer: B
Rationale: Correct pest identification is the foundation of IPM because all control
decisions depend on knowing the exact organism causing damage.
Misidentification can lead to ineffective or unnecessary pesticide applications,
increased resistance, and environmental harm. Proper diagnosis also helps
determine pest life cycle stage, thresholds, and appropriate cultural or chemical
controls. Without accurate identification, no other IPM component can be
correctly applied.
2. Which pesticide formulation is most likely to be absorbed through plant
foliage?
, A. Granular
B. Bait
C. Emulsifiable concentrate
D. Fumigant
Correct Answer: C
Rationale: Emulsifiable concentrates (ECs) are formulated to mix with water and
spread evenly on plant surfaces, allowing better foliar penetration. They often
contain solvents and surfactants that enhance absorption through waxy cuticles.
Granular and bait formulations rely on soil or ingestion activity, while fumigants
act as gases in enclosed spaces. ECs are widely used for ornamental and turf
foliar pest control due to their effectiveness in contact and systemic uptake.
3. What is the main purpose of a pesticide label?
A. Suggest marketing strategies
B. Provide legal use directions
C. List competitor products
D. Describe plant diseases only
Correct Answer: A
Rationale: The pesticide label is the legal document that defines how a product
may be used. It includes application rates, target pests, safety precautions,
environmental hazards, and restrictions. It is enforceable by law and must be
strictly followed. Ignoring label instructions is a violation of federal pesticide
regulations. Labels are not marketing tools but binding legal documents that
ensure safe and effective use.
4. Which pest is most commonly associated with irregular brown patches in
turfgrass caused by fungal infection?
A. White grubs
B. Dollar spot
, C. Aphids
D. Cutworms
Correct Answer: B
Rationale: Dollar spot is a common turf fungal disease characterized by small,
circular, straw-colored patches. It thrives in humid conditions with low nitrogen
levels. Unlike insect pests such as grubs or aphids, dollar spot is a pathogen that
affects leaf tissue. Early detection and proper fungicide rotation, along with
cultural practices like balanced fertilization, help control its spread effectively.
5. What is the primary function of surfactants in pesticide mixtures?
A. Increase vapor pressure
B. Improve spray coverage
C. Kill insects directly
D. Reduce plant growth
Correct Answer: B
Rationale: Surfactants improve the spreading, wetting, and sticking of spray
solutions on plant surfaces. They reduce surface tension, allowing droplets to
cover leaves more evenly and enhance pesticide effectiveness. Surfactants do
not kill pests directly but significantly increase the efficiency of active
ingredients. They are especially useful in ornamental and turf applications
where waxy leaf surfaces can repel sprays.
6. Which soil type generally requires the highest pesticide application rate due
to adsorption?
A. Sandy soil
B. Loam soil
C. Organic peat soil
D. Clay soil
Correct Answer: D
, Rationale: Clay soils have high cation exchange capacity and large surface area,
which increases pesticide adsorption. This binding reduces pesticide availability,
often requiring higher application rates compared to sandy soils. However,
careful calibration is essential to avoid environmental contamination. Sandy
soils, in contrast, allow faster movement and leaching, often requiring lower but
more frequent applications.
7. What is the primary symptom of iron chlorosis in ornamental plants?
A. Dark green leaves
B. Yellowing between leaf veins
C. Holes in leaves
D. Wilting stems
Correct Answer: C
Rationale: Iron chlorosis typically causes interveinal yellowing, where leaf tissue
turns yellow while veins remain green. It is often caused by high soil pH, poor
iron availability, or root stress. Although leaf holes or wilting may indicate insect
or water stress, chlorosis is a nutrient disorder affecting chlorophyll production.
Proper soil amendment or foliar iron applications are common corrective
measures.
8. What is the most effective method to prevent pesticide resistance?
A. Increase dosage regularly
B. Rotate pesticide modes of action
C. Use only one pesticide
D. Apply more frequently
Correct Answer: D
Rationale: Rotating pesticides with different modes of action reduces selection
pressure on pest populations, preventing resistant individuals from dominating.
Overuse of a single chemical group accelerates resistance development.
