🔵 1. Which of the following is the botanical name of rice?
A) Zea mays
B) Oryza sativa
C) Triticum aestivum
D) Sorghum bicolor
Answer: B) Oryza sativa
Rationale: Oryza sativa is the most widely cultivated rice species in the world.
🔵 2. Rice is mainly propagated by:
A) Cuttings
B) Seeds
C) Grafting
D) Rhizomes
Answer: B) Seeds
Rationale: Rice is typically grown from seeds either by direct seeding or transplanting.
🔵 3. The critical stage for irrigation in rice is:
A) Tillering
B) Flowering
C) Panicle initiation
D) Transplanting
Answer: C) Panicle initiation
Rationale: Water stress during panicle initiation significantly reduces yield.
🔵 4. Rice is a:
A) C3 plant
B) C4 plant
C) CAM plant
D) None of the above
Answer: A) C3 plant
Rationale: Rice follows the C3 photosynthetic pathway, typical of plants in cooler, wetter climates.
🔵 5. The optimum pH range for rice cultivation is:
A) 4.5–5.0
B) 5.5–7.0
C) 7.5–8.5
D) 8.5–9.0
Answer: B) 5.5–7.0
Rationale: Rice grows best in slightly acidic to neutral soils.
🔵 6. Ideal temperature for rice seed germination is:
A) 10–15°C
B) 16–20°C
C) 20–35°C
D) 36–45°C
Answer: C) 20–35°C
Rationale: Warm conditions favor faster and uniform germination of rice seeds.
🔵 7. Which rice-growing method saves water and increases productivity?
A) Direct seeding
B) Transplanting
C) SRI (System of Rice Intensification)
D) Relay cropping
Answer: C) SRI
Rationale: SRI uses less water and seed, enhancing root growth and yield.
🔵 8. What is the average duration of short-duration rice varieties?
A) 60–90 days
B) 90–120 days
C) 120–150 days
D) 150–180 days
Answer: B) 90–120 days
Rationale: Short-duration varieties typically mature within 3 to 4 months.
🔵 9. The nutrient most critical for tillering in rice is:
A) Nitrogen
B) Phosphorus
C) Potassium
D) Zinc
Answer: A) Nitrogen
Rationale: Nitrogen encourages vegetative growth and increases tiller formation.
🔵 10. Rice blast is caused by:
A) Pyricularia oryzae
B) Xanthomonas oryzae
C) Helminthosporium oryzae
D) Rhizoctonia solani
Answer: A) Pyricularia oryzae
Rationale: This fungus causes characteristic lesions on leaves and panicles.
🔵 11. Major insect pest of rice in India is:
A) Brown planthopper
B) Pink bollworm
C) Shoot fly
D) Stem borer
Answer: A) Brown planthopper
Rationale: Brown planthopper sucks plant sap and transmits grassy stunt virus.
🔵 12. Which of the following is a semi-dwarf high-yielding rice variety?
A) Jaya
B) IR 8
C) Pusa Basmati
D) Swarna
Answer: B) IR 8
Rationale: IR 8 was developed during the Green Revolution as a high-yielding semi-dwarf variety.
🔵 13. Rice plant requires which type of climate?
A) Cool and dry
B) Hot and dry
C) Hot and humid
D) Cold and wet
Answer: C) Hot and humid
Rationale: Rice thrives in tropical, humid climates with high rainfall.
🔵 14. Direct seeding of rice is more commonly practiced in:
A) Bihar
B) Tamil Nadu
C) Punjab
D) Kerala
Answer: C) Punjab
Rationale: Due to water scarcity and labor costs, direct seeding is promoted in Punjab.
🔵 15. Which of the following is a micronutrient essential for rice?
A) Nitrogen
B) Potassium
C) Zinc
D) Calcium
Answer: C) Zinc
Rationale: Zinc deficiency is common in rice, especially in submerged soils.
🔵 16. Leaf folder in rice belongs to which insect order?
A) Coleoptera
B) Lepidoptera
C) Hemiptera
D) Diptera
Answer: B) Lepidoptera
Rationale: Leaf folder larvae fold and feed on rice leaves, reducing photosynthesis.
🔵 17. What is the optimum plant spacing for SRI method in rice?
A) 15 × 15 cm
B) 20 × 20 cm
C) 25 × 25 cm
D) 10 × 10 cm
Answer: C) 25 × 25 cm
Rationale: Wider spacing encourages better root development and air circulation.
🔵 18. Which state has the highest rice production in India?
A) Punjab
B) Uttar Pradesh
C) Andhra Pradesh
D) West Bengal
Answer: D) West Bengal
Rationale: West Bengal leads in rice production due to favorable agro-climatic conditions.
🔵 19. Rice root nematode is controlled by:
A) Carbofuran
B) Imidacloprid
C) Malathion
D) Chlorpyrifos
Answer: A) Carbofuran
Rationale: Carbofuran is a nematicide applied to control root-knot and rice nematodes.
🔵 20. Rice is classified under which type of crop based on water requirement?
A) Dryland crop
B) Rainfed upland crop
C) Wetland crop
D) Arid crop
Answer: C) Wetland crop
Rationale: Traditional rice cultivation requires standing water or puddled fields.
🔵 21. The most susceptible stage of rice to water stress is:
A) Tillering
B) Flowering
C) Grain filling
D) Maturity
Answer: B) Flowering
Rationale: Drought during flowering leads to poor pollination and grain formation.
🔵 22. The rice variety 'Swarna' is known for its:
A) Early maturity
B) Drought resistance
C) High yield
D) Aromatic grains
Answer: C) High yield
Rationale: ‘Swarna’ is a popular high-yielding variety cultivated widely in India.
🔵 23. Iron toxicity in rice fields is commonly indicated by:
A) Chlorosis
B) Leaf bronzing
C) Leaf rolling
D) Purple discoloration
Answer: B) Leaf bronzing
Rationale: Excess iron in flooded soils causes bronzing of leaves in rice plants.
🔵 24. Optimum depth for transplanting rice seedlings is:
A) 1–2 cm
B) 2–3 cm
C) 3–5 cm
D) 5–7 cm
Answer: C) 3–5 cm
Rationale: Planting at this depth ensures proper root establishment and tillering.
🔵 25. Rice Sheath Blight is caused by:
A) Rhizoctonia solani
B) Pyricularia oryzae
C) Fusarium oxysporum
D) Sclerotinia sclerotiorum
Answer: A) Rhizoctonia solani
Rationale: This soil-borne fungus affects sheaths near the waterline, especially under high humidity.
🔵 26. Which country is the largest exporter of rice globally?
A) India
B) Thailand
C) Vietnam
D) China
Answer: A) India
Rationale: India has been the top rice exporter due to high production and surplus.
🔵 27. The aromatic compound in Basmati rice is:
A) Acetaldehyde
B) 2-acetyl-1-pyrroline
C) Ethylene
D) Isoamyl acetate
Answer: B) 2-acetyl-1-pyrroline
Rationale: This compound gives Basmati its distinct aroma.
🔵 28. The ideal stage for harvesting rice is when:
A) 50% grains are matured
B) 70% grains are matured
C) 80–85% grains are matured
D) 100% grains are matured
Answer: C) 80–85% grains are matured
Rationale: This stage ensures maximum grain quality and minimizes shattering losses.
🔵 29. Rice yellow mottle virus is spread mainly by:
A) Fungi
B) Insects
C) Nematodes
D) Birds
Answer: B) Insects
Rationale: Insect vectors such as beetles help spread the virus in rice fields.
🔵 30. In rice, the process of panicle exertion occurs during:
A) Tillering stage
B) Booting stage
C) Dough stage
D) Ripening stage
Answer: B) Booting stage
Rationale: Panicle emerges from the flag leaf sheath during booting.
🔵 31. What is the seed rate for transplanting rice using line method?
A) 10–15 kg/ha
B) 20–25 kg/ha
C) 40–60 kg/ha
D) 60–80 kg/ha
Answer: B) 20–25 kg/ha
Rationale: Line transplanting requires less seed compared to broadcasting methods.
🔵 32. Which enzyme is inhibited due to zinc deficiency in rice?
A) Amylase
B) Dehydrogenase
C) Carbonic anhydrase
D) Alcohol dehydrogenase
Answer: C) Carbonic anhydrase
Rationale: Zinc is essential for the activity of carbonic anhydrase involved in photosynthesis.
🔵 33. Which rice disease causes neck rot and poor grain filling?
A) Blast
B) Bacterial blight
C) False smut
D) Sheath blight
Answer: A) Blast
Rationale: Blast can attack the neck of panicles, reducing grain filling and yield.
🔵 34. What type of inflorescence is found in rice?
A) Raceme
B) Spike
C) Panicle
D) Umbel
Answer: C) Panicle
Rationale: Rice has a branched, loose inflorescence called a panicle.
🔵 35. Rice belongs to which family?
A) Solanaceae
B) Fabaceae
C) Poaceae
D) Brassicaceae
Answer: C) Poaceae
Rationale: Poaceae (Gramineae) is the grass family to which all cereals belong.
🔵 36. Which part of rice grain is removed during polishing?
A) Endosperm
B) Embryo
C) Aleurone layer
D) All of the above
Answer: C) Aleurone layer
Rationale: Polishing removes the aleurone layer and embryo, reducing nutrition.
🔵 37. Which method helps detect seed-borne pathogens in rice?
A) Soil test
B) Blotter method
C) ELISA
D) Float test
Answer: B) Blotter method
Rationale: It’s a reliable method for identifying seed-borne fungi in cereals.
🔵 38. For upland rice cultivation, the best suited method is:
A) Broadcasting
B) Transplanting
C) Drilling
D) Dibbling
Answer: A) Broadcasting
Rationale: In rainfed upland conditions, broadcasting is commonly used.
🔵 39. The international rice research institute (IRRI) is located in:
A) India
B) Philippines
C) Thailand
D) Japan
Answer: B) Philippines
Rationale: IRRI, Manila, is the world leader in rice research and breeding.
🔵 40. Which hormone delays senescence in rice?
A) Auxin
B) Cytokinin
C) Gibberellin
D) Ethylene
Answer: B) Cytokinin
Rationale: Cytokinins promote cell division and delay leaf aging.
🔵 41. Which of the following is used to manage bacterial blight in rice?
A) Streptomycin
B) Bordeaux mixture
C) Copper oxychloride
D) Carbendazim
Answer: A) Streptomycin
Rationale: This antibiotic is used for bacterial disease control in plants.
🔵 42. Rice is most sensitive to salt stress during:
A) Germination
B) Tillering
C) Panicle initiation
D) Flowering
Answer: A) Germination
Rationale: Salt stress affects water uptake and seedling emergence during germination.
🔵 43. Which of the following varieties is known for drought tolerance in rice?
A) IR 64
B) Sahbhagi Dhan
C) Pusa Basmati 1
D) MTU 1010
Answer: B) Sahbhagi Dhan
Rationale: Developed for upland areas, it shows better yield under moisture stress.
🔵 44. What is the typical spacing used in SRI for planting rice seedlings?
A) 10 × 10 cm
B) 15 × 15 cm
C) 20 × 20 cm
D) 25 × 25 cm
Answer: D) 25 × 25 cm
Rationale: Wider spacing reduces competition and supports vigorous tillering.
🔵 45. What is the purpose of puddling in rice fields?
A) Aeration
B) Moisture conservation
C) Weed control and reduced percolation
D) Seed germination
Answer: C) Weed control and reduced percolation
Rationale: Puddling creates a compact layer to retain water and suppress weeds.
🔵 46. Rice is considered a:
A) Short day plant
B) Long day plant
C) Day-neutral plant
D) Non-photoperiodic plant
Answer: A) Short day plant
Rationale: Rice flowers when the day length is below a critical threshold.
🔵 47. Rice stem borer is effectively managed by:
A) Light traps
B) Pheromone traps
C) Neem oil
D) All of the above
Answer: D) All of the above
Rationale: Integrated pest management includes multiple eco-friendly tools.
🔵 48. Major weed in rice fields is:
A) Parthenium
B) Echinochloa crus-galli
C) Cynodon dactylon
D) Chenopodium album
Answer: B) Echinochloa crus-galli
Rationale: Known as barnyard grass, it competes heavily with rice seedlings.
🔵 49. Rice field emits which greenhouse gas?
A) CO₂
B) Methane
C) Nitrous oxide
D) Sulphur dioxide
Answer: B) Methane
Rationale: Anaerobic decomposition in flooded soils releases methane.
🔵 50. Average water requirement for rice production is:
A) 200–400 mm
B) 500–800 mm
C) 1000–1500 mm
D) 1500–2000 mm
Answer: C) 1000–1500 mm
Rationale: Rice requires high water input, especially under traditional flooded conditions.
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