LEA Mock Test: Crop Science Questions For Today

1. Which rice ecosystem is characterized by continuous flooding and is typical for lowland, transplanted rice culture?

• a) Upland rainfed rice
• b) Irrigated lowland (flooded) rice
• c) Deepwater rice
• d) Aerobic rice

2. In maize hybrid production, what is the primary advantage of producing single-cross hybrids compared to open-pollinated varieties?

• a) Lower seed production cost
• b) Greater heterosis and uniformity
• c) Longer seed storage life
• d) Reduced need for fertilizers

3. Which nitrogen management practice reduces nitrogen losses and improves nitrogen use efficiency in upland crops?

• a) Single large basal application only
• b) Split application synchronized with crop demand
• c) Application during heavy rains
• d) Broadcasting without incorporation

4. Which legume is commonly used in the Philippines for soil improvement because of its fast biomass production and nitrogen-fixing ability?

• a) Cowpea (Vigna unguiculata)
• b) Maize
• c) Rice
• d) Sugarcane

5. What is the principal purpose of ridge planting in root and tuber crops like sweet potato?

• a) Increase soil compaction
• b) Improve drainage and root/tuber development
• c) Encourage waterlogging
• d) Prevent sprouting

6. Which of the following describes “leaf area index (LAI)” used in crop physiology?

• a) Ratio of leaf length to plant height
• b) Total leaf area per unit ground area
• c) Number of leaves per plant
• d) Leaf thickness measurement

7. Which integrated pest management (IPM) tool is primarily preventive rather than curative?

• a) Pesticide calendar with routine sprays
• b) Use of resistant varieties and crop rotation
• c) Emergency chemical fumigation
• d) Spot treatment after outbreak

8. Which soil conservation practice is most effective on sloping land to reduce runoff and soil erosion?

• a) Contour bunding and terracing
• b) Planting across the slope vertically
• c) Continuous deep plowing down the slope
• d) Burning crop residues

9. What is the main advantage of conservation agriculture (zero/minimum tillage, residue retention, crop rotation)?

• a) Immediate increase in pest outbreaks always
• b) Improved soil structure, moisture conservation and long-term sustainability
• c) Elimination of the need for crop rotation
• d) Guaranteed higher yields from year one

10. Which sampling method is commonly used to estimate pest population density across a large field?

• a) Entire-field exhaustive counting
• b) Systematic or random quadrant/plot sampling
• c) Only sampling at field borders
• d) Sampling only after harvest

11. In seed technology, what does the term “vigor” of seed refer to?

• a) Color of the seed coat
• b) Capacity of seed to perform under a wide range of field conditions
• c) Seed size only
• d) Time taken to dry seeds

12. Which tool is commonly used to measure soil pH in the field?

• a) Refractometer
• b) pH meter or pH test strips
• c) Hygrometer
• d) Anemometer

13. Which physiological disorder in tomatoes is commonly associated with calcium deficiency?

• a) Powdery mildew
• b) Blossom end rot
• c) Bacterial wilt
• d) Leaf rust

14. Which method is an example of biological nitrogen fixation used in cropping systems?

• a) Chemical urea application
• b) Inoculation of legumes with Rhizobium bacteria
• c) Foliar spray of ammonium nitrate
• d) Burning residues

15. Which postharvest practice is most important to reduce grain deterioration during storage?

• a) Maintain low grain moisture and good sanitation
• b) Store grains wet to prevent brittleness
• c) Store at high temperature and humidity
• d) Mix grains from different seasons freely

16. Which practice is characteristic of precision agriculture?

• a) Uniform blanket application of inputs across fields
• b) Site-specific management using GPS and variable-rate technology
• c) Hand broadcasting seeds with no mapping
• d) Only manual ploughing

17. Which weed species management would be best approached by using stale seedbed technique?

• a) Perennial deep-rooted weeds only
• b) Annual flushes of weed seedlings before crop sowing
• c) Weeds that emerge after harvest only
• d) Woody shrubs

18. In crop breeding, what is the purpose of backcrossing?

• a) Create entirely new species
• b) Transfer one or few desirable traits into an adapted cultivar
• c) Randomly mix genes
• d) Sterilize pollen

19. Which is a common symptom of iron deficiency in many crop species?

• a) Interveinal chlorosis of new leaves
• b) Root necrosis only
• c) General leaf thickening
• d) Excessive fruit set

20. What is the principal objective of seed certification systems?

• a) Increase seed market prices
• b) Assure genetic purity and quality standards of seed lots
• c) Restrict farmer access to seed
• d) Eliminate small seed sellers

21. Which irrigation scheduling method estimates crop water use by reference evapotranspiration (ETo) and crop coefficient (Kc)?

• a) Soil color method
• b) Blaney-Criddle only
• c) ETo × Kc (reference evapotranspiration method)
• d) Random daily watering

22. Which disease of rice is commonly caused by a fungus and characterized by panicle blight and grain discoloration?

• a) Bacterial leaf blight
• b) Sheath blight
• c) Rice blast
• d) Tungro (viral)

23. Which farm business practice improves traceability and market access for high-value crop producers?

• a) Maintaining production and sales records and lot labeling
• b) Discarding all farm records
• c) Only bartering produce
• d) Mixing product lots without labeling

24. Which factor most directly increases soil salinity problems in irrigated agriculture?

• a) Use of high-quality rainwater
• b) Poor drainage and irrigation with saline water
• c) Addition of organic compost
• d) Crop rotation with legumes

25. Which of the following is an advantage of using improved certified planting materials for smallholder farmers?

• a) Guaranteed pest outbreaks
• b) Higher genetic uniformity, vigor and yield potential
• c) Increased seed dormancy
• d) Increased postharvest losses

26. Which tool is most appropriate for quick assessment of leaf chlorophyll (as proxy for N status) in the field?

• a) Chlorophyll meter (SPAD)
• b) pH strips
• c) Refractometer
• d) Anemometer

27. Which of the following is a major constraint for cassava production in some Philippine provinces?

• a) Cassava mosaic virus (not common in Philippines)
• b) Root rot and mealybug infestation
• c) Need for heavy fertilization like cereals
• d) Inability to grow in lowlands

28. What practice is recommended to manage plant-parasitic nematodes in vegetable production?

• a) Continuous monocropping of susceptible crops
• b) Crop rotation with non-hosts and use of biofumigant cover crops
• c) Over-irrigation to drown nematodes
• d) Rely only on broad-spectrum herbicides

29. Which postharvest treatment is used to reduce insect infestation in stored grain without chemical residues?

• a) Proper sanitation and airtight hermetic storage
• b) Mixing grain with fresh wet soil
• c) Leaving grain uncovered
• d) Adding untreated compost

30. Which crop is the world’s leading source of vegetable oil produced from its seed?

• a) Sunflower
• b) Soybean
• c) Rapeseed (canola)
• d) Coconut (copra oil)

31. Which postharvest practice helps reduce aflatoxin contamination in stored maize?

• a) Drying grain to safe moisture levels and good storage hygiene
• b) Storing wet grain
• c) Mixing old and new harvests freely
• d) Keeping grain exposed to rain

32. Which management practice reduces incidence of stem-borers in rice?

• a) Synchronized planting and removal of infested stubbles
• b) Continuous ratooning without monitoring
• c) Avoid any field sanitation
• d) Always delay planting by months

33. What is the main advantage of using cover crops in orchards?

• a) Increase erosion, weed pressure and soil compaction
• b) Improve soil organic matter, reduce erosion and suppress weeds
• c) Rapid depletion of soil nutrients only
• d) Promote rodent infestation exclusively

34. Which physiological measurement helps estimate crop water stress by measuring canopy temperature?

• a) Infrared thermometry (canopy temperature measurement)
• b) Soil color observation
• c) Counting leaves only
• d) Measuring stem diameter only

35. Which of the following is an example of a mechanical weed control method suitable for smallholder farms?

• a) Hand weeding and hoeing
• b) Aerial herbicide spraying
• c) Burning entire field annually
• d) Flooding with saltwater

36. Which cereal crop has the greatest tolerance to waterlogged conditions and is often grown in flooded paddies?

• a) Wheat
• b) Rice (Oryza sativa)
• c) Sorghum
• d) Pearl millet

37. Which nutrient is most associated with promoting root development and early growth?

• a) Nitrogen (N) only
• b) Phosphorus (P)
• c) Sodium (Na)
• d) Chlorine (Cl)

38. Which policy instrument in the Philippines aims to stabilize rice supply and support farmers (example: safety net or buffer stock management)?

• a) National Food Authority (NFA) buffer stock and procurement programs
• b) Department of Education school feeding only
• c) Local zoning for urban expansion only
• d) Tourism tax incentives

39. In integrated nutrient management, which practice balances nutrient supply and maintains soil fertility sustainably?

• a) Sole reliance on chemical fertilizers
• b) Combining organic manures, green manures and judicious chemical fertilizers
• c) Burning residues to ash only
• d) Never testing soil

40. Which fungal pathogen causes rice blast, a major disease on leaves, nodes and panicles?

• a) Magnaporthe oryzae
• b) Xanthomonas oryzae
• c) Ralstonia solanacearum
• d) Phytophthora infestans

41. Which postharvest method is commonly used to reduce physiological respiration and extend shelf life of freshly harvested vegetables?

• a) Pre-cooling and cold storage
• b) Sun-drying immediately
• c) Storing at ambient high temperature
• d) Exposing to smoke

42. Which component is NOT part of Good Agricultural Practices (GAP) for crop production?

• a) Record keeping and traceability
• b) Proper pesticide use and preharvest intervals
• c) Use of banned or unregistered pesticides
• d) Worker hygiene and safe water use

43. Which rotation sequence is useful to break pest and disease cycles in cereal-based systems?

• a) Continuous rice every season
• b) Rice – legume – upland cereal
• c) Continuous monoculture without break
• d) Only fallow management

44. Which indicator is used to measure grain yield potential in a cereal crop during breeding trials?

• a) Grain weight per unit area (e.g., t/ha)
• b) Stem color
• c) Number of leaves per plant only
• d) Size of seed packet

45. Which farming practice contributes most to greenhouse gas emissions among cropping activities?

• a) Methane emissions from flooded rice systems
• b) Manual weeding only
• c) Using horse-drawn ploughs
• d) Growing cover crops

46. Which method is commonly used to propagate virus-free potato seed tubers?

• a) Planting farm-saved tubers without testing
• b) Use of certified seed tubers from accredited sources
• c) Allowing volunteer plants to be seed source
• d) Storing tubers in wet, warm conditions

47. Which practice is part of integrated soil fertility management (ISFM)?

• a) Combining mineral fertilizers with organic inputs and improved germplasm
• b) Ignoring soil test results
• c) Exclusive reliance on one fertilizer type
• d) Removing all crop residues

48. Which storage structure is designed to reduce postharvest losses of grains in smallholder contexts by protecting from pests and moisture?

• a) Traditional open heap on bare ground
• b) Elevated, well-ventilated granary or hermetic bags
• c) Storing under tree canopy exposed to animals
• d) Leaving grain in the field

49. Which biotech tool allows marker-assisted selection to speed up breeding programs?

• a) Use of molecular markers linked to traits
• b) Only visual selection without markers
• c) Random seed mixing
• d) Burning breeding plots

50. Which economic analysis metric helps a farmer decide if an investment in an improved cultivar is profitable?

• a) Benefit–cost ratio (BCR) or net present value (NPV)
• b) Counting only number of seeds used
• c) Ignoring costs and only recording yields
• d) Estimating by visual farm appearance