A golf course putting green exhibits dollar spot symptoms despite routine
fungicide applications. Which fungicide class is most likely to have lost
efficacy due to a target-site mutation in Sclerotinia homoeocarpa?
A. DMI fungicides (sterol demethylation inhibitors)
B. QoI fungicides (strobilurins)
C. MBC fungicides (benzimidazoles)
D. Dicarboximides
Correct Answer: C - MBC fungicides (benzimidazoles)
RATIONALE
MBC resistance is commonly associated with a single point mutation
in the beta-tubulin gene, leading to rapid loss of efficacy in dollar spot
populations. QoI and DMI resistance also occur but are less frequently
linked to this specific mechanism in S. homoeocarpa. Dicarboximides
are not typically used for dollar spot control.
Question 2
Which of the following best explains why repeated applications of the same
neonicotinoid to control Japanese beetle grubs in turf can lead to secondary
pest outbreaks?
A. Development of resistance in the target pest
B. Elimination of natural enemies that suppress secondary pests
C. Phytotoxicity to turfgrass roots
D. Increased soil pH reducing pesticide efficacy
Correct Answer: B - Elimination of natural enemies that suppress
secondary pests
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, RATIONALE
Neonicotinoids can be toxic to beneficial insects and soil-dwelling
predators, disrupting natural control of secondary pests like chinch
bugs or mites. Resistance may occur but is not the primary cause of
secondary outbreaks. Phytotoxicity and pH effects are not directly
linked to secondary pest resurgence.
Question 3
A commercial applicator must calibrate a backpack sprayer to apply 2 lb
ai/acre of a wettable powder. The sprayer has a 4-gallon tank and delivers 0.5
GPM. How many acres can be treated per tank if the application rate is 20
GPA?
A. 0.2 acres
B. 0.4 acres
C. 0.8 acres
D. 1.0 acres
Correct Answer: A - 0.2 acres
RATIONALE
At 20 gallons per acre, a 4-gallon tank covers 4/20 = 0.2 acres. The
GPM and ai rate are distractors. This is a basic calibration calculation
for sprayer coverage.
Question 4
Which statement correctly describes the role of the signal word on a pesticide
label for a Category 3 product?
A. It indicates the toxicity category and required PPE.
B. It specifies the target pest spectrum.
C. It provides the EPA registration number.
D. It lists the active ingredient concentration.
Correct Answer: A - It indicates the toxicity category and
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, required PPE.
RATIONALE
The signal word (DANGER, WARNING, CAUTION) reflects acute
toxicity and dictates minimum PPE. Other label elements like EPA
number and active ingredient are separate. Target pest spectrum is
found in the directions for use.
Question 5
During a site assessment, you find lace bugs on azaleas. Which cultural
practice is LEAST likely to reduce future infestations?
A. Avoiding excessive nitrogen fertilization
B. Planting azaleas in shaded areas
C. Removing fallen leaves in autumn
D. Applying a broad-spectrum insecticide monthly
Correct Answer: D - Applying a broad-spectrum insecticide
monthly
RATIONALE
Monthly broad-spectrum insecticide applications can kill natural
enemies and lead to resurgence, making it the least sustainable
practice. Cultural controls like shade and sanitation reduce stress and
overwintering sites. Avoiding excess nitrogen prevents succulent
growth favored by lace bugs.
Question 6
Which of the following is a key difference between contact and systemic
insecticides when managing borers in ornamental trees?
A. Contact insecticides are more effective against larvae inside trunks.
B. Systemic insecticides require ingestion by the pest.
C. Systemic insecticides are translocated and can control pests not
directly sprayed.
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