Ohio Commercial Pesticide Applicator Certification Category 2a (Agronomic Pest Control) Practice Exam Questions And Correct Answers (Verified) Latest Update 2026/2027 | Graded A+ | 100% ASSURED PASS.

Ohio Commercial Pesticide Applicator Certification Category 2a (Agronomic Pest Control) Practice Exam Questions And Correct Answers (Verified) Latest Update 2026/2027 | Graded A+ | 100% ASSURED PASS. 1. Which of the following is a common symptom of corn rootworm damage in corn crops? A. Leaf curling B. Root pruning and lodging C. Powdery mildew on leaves D. Stunted tassel development B Corn rootworm larvae feed on corn roots, causing root pruning. This weakens the plant’s anchorage, often resulting in lodging, particularly in late season. 2. What is the primary pest controlled by using atrazine in corn? A. European corn borer B. Grass and broadleaf weeds C. Corn rootworm D. Soybean cyst nematode B Atrazine is a selective herbicide used primarily for controlling grass and broadleaf weeds in corn, not insect pests. 3. The most effective timing for postemergence herbicide application in soybeans is: A. Before planting B. At the V1–V2 leaf stage C. After harvest D. During seed dormancy B Postemergence herbicides are most effective when applied to young, actively growing weeds, often during the early vegetative stages of soybeans. 4. Which nematode species commonly affects corn and soybean roots in Ohio? A. Root-knot nematode B. Pinewood nematode C. Soybean cyst nematode D. Dagger nematode C Soybean cyst nematode is a major pest of soybeans in Ohio, causing stunted growth and reduced yield, often with no obvious above-ground symptoms early on. 5. Which insect is considered a major defoliator of soybean leaves in Ohio? A. Japanese beetle B. Corn earworm C. Alfalfa weevil D. Armyworm A Japanese beetles feed on soybean foliage, skeletonizing the leaves. This can reduce photosynthesis and yield if populations are high. 6. What is the primary mode of action of glyphosate? A. Inhibition of acetolactate synthase B. Inhibition of photosystem II C. Inhibition of EPSP synthase D. Disruption of insect nervous system C Glyphosate inhibits EPSP synthase, an enzyme involved in the shikimic acid pathway, which is essential for amino acid synthesis in plants. 7. When applying soil-applied insecticides to corn, which factor is most important for maximizing efficacy? A. Application during full tassel B. Incorporation into the soil near roots C. Spraying in mid-afternoon D. Avoiding pre-plant timing B Soil-applied insecticides are most effective when incorporated near the root zone where larvae, such as corn rootworms, feed. 8. Which weed is commonly resistant to glyphosate in Ohio agronomic fields? A. Common lambsquarters B. Palmer amaranth C. Velvetleaf D. Crabgrass B Palmer amaranth has documented cases of glyphosate resistance in multiple states, including Ohio, and requires integrated management. 9. What is the legal requirement for using restricted-use pesticides in Ohio? A. Only homeowners can apply them B. Applicators must hold a commercial pesticide license C. No certification is required D. They can only be used in greenhouses B Restricted-use pesticides can only be applied by certified applicators who have met training and licensing requirements, ensuring safe and effective use. 10. Which of the following is a systemic insecticide? A. Carbaryl B. Imidacloprid C. Pyrethrin D. Sulfur B Imidacloprid is systemic, meaning it moves within the plant tissue and can control insects feeding on treated plants internally. 11. Which cultural practice can reduce incidence of corn earworm in Ohio? A. Early planting of corn B. Overhead irrigation C. Delayed harvest D. Continuous corn planting A Early planting can help corn escape peak corn earworm populations, reducing infestation risk. 12. Which organophosphate insecticide primarily targets sucking pests in soybeans? A. Chlorpyrifos B. Acephate C. Lambda-cyhalothrin D. Bacillus thuringiensis