Crop Protection Management – Long Answer Questions
Medium Level (Application & Explanation)
Q1. Why is early weed removal important for better crop yield? Explain with reasons.
Answer:
- Weeds compete with crops for nutrients, water, light, and space.
- In the early growth stage, young crops are weak and get suppressed easily.
- Early removal reduces competition and helps roots grow strong.
- Crops get more sunlight and make more food by photosynthesis.
- It also reduces weed seed spread for the next season.
- Early weeding leads to healthy plants and a higher yield.
Q2. Explain the difference between herbicides, insecticides, and fungicides. How are they used safely?
Answer:
- Herbicides kill weeds. Insecticides kill insects. Fungicides kill fungi.
- They may be used as sprays on plants or for seed and soil treatment.
- Use the right chemical for the right pest or disease.
- Follow the recommended dose and timing strictly.
- Avoid overuse, as it can harm plants, animals, and cause pollution.
- Wear protective gear and keep chemicals away from water sources.
Q3. How do intercropping and crop rotation help in controlling weeds and pests?
Answer:
- Intercropping grows two crops together. This covers the soil and reduces weed growth.
- Different crops use nutrients differently. This reduces competition and pest build-up.
- Crop rotation changes the crop each season. Pests do not find their host every time.
- Many weeds and pests have specific hosts. Rotation breaks their life cycle.
- Rotation also improves soil health and reduces diseases.
- Together, these methods lower chemical use and keep fields productive.
Q4. What are common sources of plant pathogens and how can farmers prevent disease spread?
Answer:
- Plant pathogens like bacteria, fungi, and viruses spread through soil, water, and air.
- They may also stay in crop residues and infected seeds.
- Use proper seed bed preparation to reduce soil-borne infections.
- Do timely sowing to avoid peak disease periods.
- Choose resistant varieties to reduce disease risk.
- Keep fields clean, remove infected parts, and avoid water stagnation.
Q5. Explain how mechanical removal and deep summer ploughing help in controlling weeds and pests.
Answer:
- Mechanical removal means hand weeding or using tools to uproot weeds.
- It removes weeds with roots, so they do not compete with crops.
- Deep ploughing in hot summer brings weed seeds and pest stages to the surface.
- Sun and heat kill many exposed weeds, insects, and fungi.
- It also buries fresh seeds deeper, which reduces their germination.
- These methods lower reliance on chemicals and protect the environment.
High Complexity (Analysis & Scenario-Based)
Q6. A farmer sees curled leaves, sticky surfaces, and yellowing in a crop. Identify the likely pest group and suggest a safe control plan.
Answer:
- The signs show sap-sucking insects like aphids or jassids.
- They suck cell sap, cause curling, yellowing, and sticky honeydew.
- First, remove heavily infested leaves and maintain field hygiene.
- Encourage natural enemies and avoid harsh sprays at first.
- If needed, use the correct insecticide at the recommended dose and timing.
- In future, use resistant varieties, timely sowing, and intercropping to reduce risk.
Q7. A village used high doses of pesticides and noticed dead fish in a canal and fewer honeybees. Analyze the problem and give a better approach.
Answer:
- Overuse caused chemical pollution and harmed beneficial organisms.
- Water bodies got contaminated, so fish died.
- Honeybees and other pollinators were also killed or repelled.
- Shift to preventive measures like crop rotation, resistant varieties, and clean fields.
- Use mechanical control and biological methods first.
- Apply pesticides only when needed, at the right dose, and away from water sources.
Q8. Compare cutting, sucking, and boring types of insect damage. Plan how to monitor and manage each in a season.
Answer:
- Cutting insects chew leaves, stems, or roots and cause visible holes.
- Sucking insects take sap, causing curling, yellowing, and stunted growth.
- Borers enter stems or fruits, leaving holes and internal damage.
- Monitor weekly: look for chewing signs, sticky honeydew, and borer entry holes.
- Remove affected parts, keep fields clean, and use traps or light monitoring where possible.
- Use the right insecticide only if needed, and follow safe doses and timing.
Q9. A family stores wheat at home and faces grain loss after two months. Analyze possible causes and suggest preventive steps.
Answer:
- Loss can be due to biotic factors: insects, rodents, fungi, mites, and bacteria.
- It can also be due to abiotic factors: high moisture and temperature.
- Dry grains to a safe moisture level before storage.
- Use clean, dry, and rodent-proof containers or bins.
- Keep the store aerated, cool, and check grains regularly.
- Remove infested grain quickly and keep the area clean and dry.
Q10. A field shows Xanthium, Parthenium, and Cyperinus rotundus during early crop growth. Predict effects on yield and propose a control calendar.
Answer:
- These weeds will compete for nutrients, water, and light.
- Early growth will be suppressed, leading to poor yield later.
- Start with deep summer ploughing to expose seeds and roots.
- Do early weeding within the first few weeks of sowing.
- If needed, use the correct herbicide at the right time and dose.
- Follow up with intercropping, mulching if possible, and regular field checks.