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Colorado Category 303 (Ornamental and Turf)
Certification Exam | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION:
This comprehensive set of multiple-choice questions is designed for the Colorado
Category 303 (Ornamental and Turf) Exam, administered by the Colorado Department of
Agriculture. The closed-book, multiple-choice exam assesses the knowledge needed for
Commercial or Limited Commercial Applicator licensing, emphasizing pest identification
and biology, integrated pest management, pesticide labels and formulations, safety and
environmental protection, and equipment calibration for landscape, turfgrass, and
ornamental plant settings.
QUESTION 1
Which of the following is a common cool-season turfgrass species widely used in
Colorado lawns?
A. Bermudagrass
B. Zoysiagrass
C. Kentucky bluegrass
D. Centipedegrass
CORRECT ANSWER: C. Kentucky bluegrass
EXPERT RATIONALE: Kentucky bluegrass thrives in Colorado’s cool climate;
bermudagrass, zoysiagrass, and centipedegrass are warm-season grasses that perform
poorly in the state.
QUESTION 2
A broadleaf weed with a rosette of deeply toothed leaves and bright yellow flowers
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commonly infesting turf is:
A. Crabgrass
B. Dandelion
C. Annual bluegrass
D. White clover
CORRECT ANSWER: B. Dandelion
EXPERT RATIONALE: Dandelion (Taraxacum officinale) has characteristic yellow flowers
and deeply lobed leaves, while crabgrass is a grassy annual weed.
QUESTION 3
What summer annual grassy weed is identified by its wide leaf blade, prostrate growth
habit, and a membranous ligule, often going to seed in mid to late summer?
A. Quackgrass
B. Smooth crabgrass
C. Nimblewill
D. Tall fescue
CORRECT ANSWER: B. Smooth crabgrass
EXPERT RATIONALE: Smooth crabgrass is a warm-season annual that spreads by tillering
and forms seed heads in July and August; quackgrass is a perennial with clasping
auricles.
QUESTION 4
Which turfgrass disease appears as silver dollar-sized, sunken patches with a dark
border and can develop a cottony mycelium in early morning?
A. Necrotic ring spot
B. Dollar spot
C. Brown patch
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D. Rust
CORRECT ANSWER: B. Dollar spot
EXPERT RATIONALE: Dollar spot produces small, bleached patches on closely mown turf;
brown patch forms larger irregular areas and necrotic ring spot causes circular rings or
arcs.
QUESTION 5
Necrotic ring spot, a serious disease of Kentucky bluegrass, primarily affects which part
of the plant?
A. Leaf blades only
B. Crowns and roots
C. Stolons and rhizomes
D. Seed heads
CORRECT ANSWER: B. Crowns and roots
EXPERT RATIONALE: Necrotic ring spot is a root/crown disease causing dark rotting of
crowns and roots, leading to frog-eye patterns of dead turf in mid-summer.
QUESTION 6
The larval stage of scarab beetles that feed on grass roots, causing wilting and turf that
can be rolled back like a carpet, is known as:
A. Cutworms
B. White grubs
C. Sod webworms
D. Billbug larvae
CORRECT ANSWER: B. White grubs
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EXPERT RATIONALE: White grubs (e.g., Japanese beetle, masked chafer) are C-shaped
larvae that sever grass roots, resulting in spongy, dying turf that lifts easily.
QUESTION 7
Sod webworm larvae are most active during what time of day?
A. Midday
B. Late afternoon
C. Early morning
D. Night
CORRECT ANSWER: D. Night
EXPERT RATIONALE: Sod webworm caterpillars hide in silk-lined burrows during the day
and feed on grass blades at night, causing small brown patches.
QUESTION 8
Which insect pest skeletonizes turfgrass leaves, leaving clear windowpaning that later
turns brown, with adults being small brown moths that fly in a zigzag pattern when
disturbed?
A. Chinch bug
B. Cutworm
C. Sod webworm
D. Billbug
CORRECT ANSWER: C. Sod webworm
EXPERT RATIONALE: Sod webworm larvae chew notches and scrape leaf surfaces,
causing transparent patches; adult crambid moths exhibit erratic flight when lawns are
walked upon.
Colorado Category 303 (Ornamental and Turf)
Certification Exam | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION:
This comprehensive set of multiple-choice questions is designed for the Colorado
Category 303 (Ornamental and Turf) Exam, administered by the Colorado Department of
Agriculture. The closed-book, multiple-choice exam assesses the knowledge needed for
Commercial or Limited Commercial Applicator licensing, emphasizing pest identification
and biology, integrated pest management, pesticide labels and formulations, safety and
environmental protection, and equipment calibration for landscape, turfgrass, and
ornamental plant settings.
QUESTION 1
Which of the following is a common cool-season turfgrass species widely used in
Colorado lawns?
A. Bermudagrass
B. Zoysiagrass
C. Kentucky bluegrass
D. Centipedegrass
CORRECT ANSWER: C. Kentucky bluegrass
EXPERT RATIONALE: Kentucky bluegrass thrives in Colorado’s cool climate;
bermudagrass, zoysiagrass, and centipedegrass are warm-season grasses that perform
poorly in the state.
QUESTION 2
A broadleaf weed with a rosette of deeply toothed leaves and bright yellow flowers
,2|Page
commonly infesting turf is:
A. Crabgrass
B. Dandelion
C. Annual bluegrass
D. White clover
CORRECT ANSWER: B. Dandelion
EXPERT RATIONALE: Dandelion (Taraxacum officinale) has characteristic yellow flowers
and deeply lobed leaves, while crabgrass is a grassy annual weed.
QUESTION 3
What summer annual grassy weed is identified by its wide leaf blade, prostrate growth
habit, and a membranous ligule, often going to seed in mid to late summer?
A. Quackgrass
B. Smooth crabgrass
C. Nimblewill
D. Tall fescue
CORRECT ANSWER: B. Smooth crabgrass
EXPERT RATIONALE: Smooth crabgrass is a warm-season annual that spreads by tillering
and forms seed heads in July and August; quackgrass is a perennial with clasping
auricles.
QUESTION 4
Which turfgrass disease appears as silver dollar-sized, sunken patches with a dark
border and can develop a cottony mycelium in early morning?
A. Necrotic ring spot
B. Dollar spot
C. Brown patch
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D. Rust
CORRECT ANSWER: B. Dollar spot
EXPERT RATIONALE: Dollar spot produces small, bleached patches on closely mown turf;
brown patch forms larger irregular areas and necrotic ring spot causes circular rings or
arcs.
QUESTION 5
Necrotic ring spot, a serious disease of Kentucky bluegrass, primarily affects which part
of the plant?
A. Leaf blades only
B. Crowns and roots
C. Stolons and rhizomes
D. Seed heads
CORRECT ANSWER: B. Crowns and roots
EXPERT RATIONALE: Necrotic ring spot is a root/crown disease causing dark rotting of
crowns and roots, leading to frog-eye patterns of dead turf in mid-summer.
QUESTION 6
The larval stage of scarab beetles that feed on grass roots, causing wilting and turf that
can be rolled back like a carpet, is known as:
A. Cutworms
B. White grubs
C. Sod webworms
D. Billbug larvae
CORRECT ANSWER: B. White grubs
, 4|Page
EXPERT RATIONALE: White grubs (e.g., Japanese beetle, masked chafer) are C-shaped
larvae that sever grass roots, resulting in spongy, dying turf that lifts easily.
QUESTION 7
Sod webworm larvae are most active during what time of day?
A. Midday
B. Late afternoon
C. Early morning
D. Night
CORRECT ANSWER: D. Night
EXPERT RATIONALE: Sod webworm caterpillars hide in silk-lined burrows during the day
and feed on grass blades at night, causing small brown patches.
QUESTION 8
Which insect pest skeletonizes turfgrass leaves, leaving clear windowpaning that later
turns brown, with adults being small brown moths that fly in a zigzag pattern when
disturbed?
A. Chinch bug
B. Cutworm
C. Sod webworm
D. Billbug
CORRECT ANSWER: C. Sod webworm
EXPERT RATIONALE: Sod webworm larvae chew notches and scrape leaf surfaces,
causing transparent patches; adult crambid moths exhibit erratic flight when lawns are
walked upon.
