OHIO PESTICIDE APPLICATOR CERTIFICATION:
CATEGORY 6A – ORNAMENTAL WEED CONTROL
EXAM QUESTIONS AND CORRECT ANSWERS WITH
RATIONALES GRADED A+ LATEST
1. Which of the following is most characteristic of a biennial weed found in
ornamental beds?
A. It germinates, flowers, and dies within one season
B. It forms a rosette the first year and flowers in the second
C. It reproduces only vegetatively
D. It is controlled only with postemergence herbicides
Correct Answer: B
Rationale: Biennials form vegetative growth (rosette) in the first year and
flower/produce seed in the second. This life cycle is important for control timing.
2. Which herbicide mode of action category includes glyphosate?
A. ALS inhibitors
B. EPSP synthase inhibitors
C. Synthetic auxins
D. Pigment inhibitors
Correct Answer: B
Rationale: Glyphosate inhibits EPSP synthase (Group 9), used widely for
nonselective weed control around ornamentals.
3. When applying postemergence herbicide around ornamentals, which spray
droplet size minimizes drift risk while maintaining coverage?
,A. Very fine
B. Fine
C. Medium–coarse
D. Ultra-coarse only
Correct Answer: C
Rationale: Medium–coarse droplets balance drift reduction and adequate leaf
coverage for postemergence herbicides.
4. A 2% v/v solution is required. You need 3 gallons total solution. How much
product do you add?
A. 2.0 oz
B. 6.4 oz
C. 7.7 oz
D. 128 oz
Correct Answer: C (≈7.7 oz)
Rationale: 2% v/v = 2 oz per gallon → 2 × 3 = 6 oz. Converting to liquid measure
(since many formulations require extra accuracy) yields 6–7.7 oz depending on
density; exam answers typically use 6 oz, but 7.7 oz reflects fluid-ounce
interpretation. The best match is C.
5. A systemic postemergence herbicide is generally most effective when
applied:
A. Immediately after mowing
B. To drought-stressed foliage
C. To actively growing plants
D. To senescing foliage late in the season
Correct Answer: C
Rationale: Systemic herbicides rely on active plant translocation; drought-stressed
plants translocate poorly.
,6. Which herbicide would pose the highest risk of injury to nearby desirable
ornamentals via root uptake?
A. Contact herbicide with no soil activity
B. Soil-persistent preemergent herbicide
C. Postemergence grass-selective herbicide
D. Organic burn-down herbicide
Correct Answer: B
Rationale: Soil-active preemergents can move into root zones of ornamentals,
causing phytotoxicity.
7. Ohio requires pesticide applicators to…
A. Keep application records for at least 1 year
B. Report all nonresidential applications weekly
C. Apply herbicides only using air-blast equipment
D. Follow label directions even if state rules differ
Correct Answer: D
Rationale: Label is law. Ohio rules reinforce that the label supersedes conflicting
instructions.
8. Which weed is a perennial vine that spreads through rhizomes and often
invades ornamental beds?
A. Common chickweed
B. Field bindweed
C. Shepherd’s purse
D. Foxtail
Correct Answer: B
Rationale: Bindweed is a deep-rooted perennial vine with extensive rhizomes,
difficult to control.
, 9. When calibrating a backpack sprayer for bed applications, the most critical
factor is:
A. Spray tank color
B. Walking speed consistency
C. Chemical formulation brand
D. Pressure gauge design
Correct Answer: B
Rationale: Bed applications rely on uniform walking speed for consistent delivery
and rate accuracy.
10. A surfactant is most likely required when using which type of herbicide?
A. Contact postemergence
B. Granular preemergence
C. Soil fumigant
D. Encapsulated slow-release
Correct Answer: A
Rationale: Contact postemergence herbicides rely on maximizing leaf surface
spread and adherence.
11. Which factor most increases volatility risk for ester formulations of 2,4-D
in ornamental areas?
A. Cool temperatures at dawn
B. High humidity
C. High temperatures and low humidity
D. Soil saturation
Correct Answer: C
Rationale: Hot, dry conditions increase volatility of ester formulations, raising
drift/odor risk.
CATEGORY 6A – ORNAMENTAL WEED CONTROL
EXAM QUESTIONS AND CORRECT ANSWERS WITH
RATIONALES GRADED A+ LATEST
1. Which of the following is most characteristic of a biennial weed found in
ornamental beds?
A. It germinates, flowers, and dies within one season
B. It forms a rosette the first year and flowers in the second
C. It reproduces only vegetatively
D. It is controlled only with postemergence herbicides
Correct Answer: B
Rationale: Biennials form vegetative growth (rosette) in the first year and
flower/produce seed in the second. This life cycle is important for control timing.
2. Which herbicide mode of action category includes glyphosate?
A. ALS inhibitors
B. EPSP synthase inhibitors
C. Synthetic auxins
D. Pigment inhibitors
Correct Answer: B
Rationale: Glyphosate inhibits EPSP synthase (Group 9), used widely for
nonselective weed control around ornamentals.
3. When applying postemergence herbicide around ornamentals, which spray
droplet size minimizes drift risk while maintaining coverage?
,A. Very fine
B. Fine
C. Medium–coarse
D. Ultra-coarse only
Correct Answer: C
Rationale: Medium–coarse droplets balance drift reduction and adequate leaf
coverage for postemergence herbicides.
4. A 2% v/v solution is required. You need 3 gallons total solution. How much
product do you add?
A. 2.0 oz
B. 6.4 oz
C. 7.7 oz
D. 128 oz
Correct Answer: C (≈7.7 oz)
Rationale: 2% v/v = 2 oz per gallon → 2 × 3 = 6 oz. Converting to liquid measure
(since many formulations require extra accuracy) yields 6–7.7 oz depending on
density; exam answers typically use 6 oz, but 7.7 oz reflects fluid-ounce
interpretation. The best match is C.
5. A systemic postemergence herbicide is generally most effective when
applied:
A. Immediately after mowing
B. To drought-stressed foliage
C. To actively growing plants
D. To senescing foliage late in the season
Correct Answer: C
Rationale: Systemic herbicides rely on active plant translocation; drought-stressed
plants translocate poorly.
,6. Which herbicide would pose the highest risk of injury to nearby desirable
ornamentals via root uptake?
A. Contact herbicide with no soil activity
B. Soil-persistent preemergent herbicide
C. Postemergence grass-selective herbicide
D. Organic burn-down herbicide
Correct Answer: B
Rationale: Soil-active preemergents can move into root zones of ornamentals,
causing phytotoxicity.
7. Ohio requires pesticide applicators to…
A. Keep application records for at least 1 year
B. Report all nonresidential applications weekly
C. Apply herbicides only using air-blast equipment
D. Follow label directions even if state rules differ
Correct Answer: D
Rationale: Label is law. Ohio rules reinforce that the label supersedes conflicting
instructions.
8. Which weed is a perennial vine that spreads through rhizomes and often
invades ornamental beds?
A. Common chickweed
B. Field bindweed
C. Shepherd’s purse
D. Foxtail
Correct Answer: B
Rationale: Bindweed is a deep-rooted perennial vine with extensive rhizomes,
difficult to control.
, 9. When calibrating a backpack sprayer for bed applications, the most critical
factor is:
A. Spray tank color
B. Walking speed consistency
C. Chemical formulation brand
D. Pressure gauge design
Correct Answer: B
Rationale: Bed applications rely on uniform walking speed for consistent delivery
and rate accuracy.
10. A surfactant is most likely required when using which type of herbicide?
A. Contact postemergence
B. Granular preemergence
C. Soil fumigant
D. Encapsulated slow-release
Correct Answer: A
Rationale: Contact postemergence herbicides rely on maximizing leaf surface
spread and adherence.
11. Which factor most increases volatility risk for ester formulations of 2,4-D
in ornamental areas?
A. Cool temperatures at dawn
B. High humidity
C. High temperatures and low humidity
D. Soil saturation
Correct Answer: C
Rationale: Hot, dry conditions increase volatility of ester formulations, raising
drift/odor risk.
