100 Crop Protection MCQs for PRC Agriculturist Licensure Exam

1. Which of the following is considered a biotrophic pathogen?

• a) Fusarium oxysporum
• b) Pythium aphanidermatum
• c) Puccinia graminis
• d) Sclerotinia sclerotiorum

2. Which part of the disease triangle can be controlled by planting resistant varieties?

• a) Environment
• b) Pathogen
• c) Host
• d) All of the above

3. The rice disease known as “tungro” is caused by:

• a) Fungi
• b) Bacteria
• c) Virus
• d) Nematodes

4. Which fungal structure is commonly responsible for initiating new infections?

• a) Sclerotia
• b) Chlamydospores
• c) Conidia
• d) Mycelia

5. Which symptom is associated with vascular wilt diseases?

• a) Leaf curling
• b) Chlorosis
• c) Internal discoloration of stem
• d) Leaf spot

6. What is the primary vector of Rice Tungro Bacilliform Virus?

• a) Leaf folder
• b) Green leafhopper
• c) Brown planthopper
• d) Gall midge

7. Which pathogen causes bacterial leaf blight in rice?

• a) Xanthomonas oryzae pv. oryzae
• b) Pseudomonas fluorescens
• c) Rhizoctonia solani
• d) Ustilago maydis

8. Which group of fungi produces aflatoxins?

• a) Penicillium spp.
• b) Aspergillus spp.
• c) Alternaria spp.
• d) Fusarium spp.

9. Powdery mildew differs from downy mildew by:

• a) Requiring higher humidity
• b) Having spores on the upper leaf surface
• c) Having no visible symptoms
• d) Producing oospores

10. Which of the following is a postharvest fungal disease?

• a) Club root
• b) Citrus canker
• c) Anthracnose
• d) Corn smut

11. What is the causal organism of rice sheath blight?

• a) Rhizoctonia solani
• b) Magnaporthe oryzae
• c) Fusarium moniliforme
• d) Ustilaginoidea virens

12. Which nematode is associated with root-knot symptoms?

• a) Heterodera spp.
• b) Meloidogyne spp.
• c) Globodera spp.
• d) Pratylenchus spp.

13. Which of the following diseases is caused by a virus in tomatoes?

• a) Fusarium wilt
• b) Bacterial wilt
• c) Tomato mosaic
• d) Early blight

14. The resting structure of Plasmodiophora brassicae is called:

• a) Cyst
• b) Zoospore
• c) Sporangium
• d) Resting spore

15. Bacterial ooze is a diagnostic sign of:

• a) Fusarium wilt
• b) Bacterial wilt
• c) Leaf blight
• d) Late blight

16. In the hypersensitive response, infected plant cells:

• a) Multiply rapidly
• b) Become dormant
• c) Die quickly to limit pathogen spread
• d) Release toxins

17. Which among the following is a seed-borne pathogen in rice?

• a) Rhizoctonia solani
• b) Xanthomonas oryzae
• c) Pyricularia oryzae
• d) Cercospora oryzae

18. What is the scientific name of the causal agent of corn smut?

• a) Ustilago maydis
• b) Puccinia sorghi
• c) Cercospora zeae-maydis
• d) Diplodia maydis

19. Virulence refers to:

• a) The capacity to spread
• b) The ability to evade host defenses
• c) The degree of pathogenicity
• d) The ability to survive without a host

20. The term “blight” is best defined as:

• a) Lesions on stems
• b) A sudden, complete, and extensive death of plant tissues
• c) Fungal growth on leaves
• d) Plant galls

21. Which insect pest is known as the “dead heart” causing pest in rice during early growth?

• a) Rice bug
• b) Brown planthopper
• c) Yellow stem borer
• d) Leaf folder

22. Which stage of the rice bug (Leptocorisa oratorius) causes the most economic damage?

• a) Egg
• b) Nymph
• c) Adult
• d) Pupa

23. What is the most common mode of feeding of aphids?

• a) Chewing
• b) Rasping
• c) Piercing and sucking
• d) Biting

24. The scientific name of the brown planthopper is:

• a) Nilaparvata lugens
• b) Nezara viridula
• c) Leptocorisa acuta
• d) Dicladispa armigera

25. Which insect pest is known to cause “hopper burn” in rice fields?

• a) Green leafhopper
• b) Yellow stem borer
• c) Brown planthopper
• d) Rice hispa

26. The rice hispa (Dicladispa armigera) primarily damages which part of the plant?

• a) Grain
• b) Leaf
• c) Stem
• d) Root

27. Which insect pest is a vector of rice grassy stunt virus?

• a) Green leafhopper
• b) Brown planthopper
• c) Rice hispa
• d) Yellow stem borer

28. In which crop is the shoot and fruit borer (Leucinodes orbonalis) a major pest?

• a) Tomato
• b) Brinjal
• c) Chili
• d) Okra

29. Which chewing insect pest causes damage to corn by boring into its ears?

• a) Corn leaf aphid
• b) Corn earworm
• c) Green leafhopper
• d) Rice hispa

30. Which insect pest commonly causes white patches on rice leaves due to feeding?

• a) Brown planthopper
• b) Rice hispa
• c) Stem borer
• d) Gall midge

31. What is the most damaging insect pest of stored corn in the Philippines?

• a) Sitophilus oryzae
• b) Tribolium castaneum
• c) Sitophilus zeamais
• d) Rhyzopertha dominica

32. The fruit fly species that infests mangoes in the Philippines is:

• a) Bactrocera dorsalis
• b) Dacus cucurbitae
• c) Ceratitis capitata
• d) Anastrepha ludens

33. Which pest causes “hopper burn” in mango seedlings?

• a) Mango twig borer
• b) Mango leafhopper
• c) Mango fruit fly
• d) Mango mealybug

34. What is the recommended management strategy for corn borer (Ostrinia furnacalis)?

• a) Use of Trichogramma
• b) Application of herbicide
• c) Bagging of fruits
• d) Handpicking of eggs

35. Which insect pest causes wilting in young tomato plants?

• a) Leaf miner
• b) Cutworm
• c) Fruit borer
• d) Aphids

36. In vegetables, the diamondback moth is a major pest of:

• a) Solanaceous crops
• b) Cucurbits
• c) Brassicas
• d) Legumes

37. What is the damage symptom of banana weevil borer?

• a) Wilting of leaves and plant collapse
• b) Leaf curling
• c) Fruit spotting
• d) Fruit cracking

38. Which of the following weeds is parasitic in nature?

• a) Cyperus rotundus
• b) Amaranthus spinosus
• c) Striga asiatica
• d) Echinochloa crus-galli

39. Which herbicide is used for selective control in transplanted rice?

• a) Glyphosate
• b) Butachlor
• c) Paraquat
• d) Atrazine

40. “False seedbed” technique is used to control:

• a) Insects
• b) Nematodes
• c) Weeds
• d) Soil erosion

41. Which of the following is a pre-emergence herbicide commonly used in maize?

• a) 2,4-D
• b) Pendimethalin
• c) Paraquat
• d) Glyphosate

42. Which weed commonly infests sugarcane fields and is difficult to control?

• a) Cyperus rotundus
• b) Amaranthus viridis
• c) Digitaria sanguinalis
• d) Echinochloa crus-galli

43. Which of the following is an example of a biological control agent used against aphids?

• a) Ladybird beetle
• b) Spider mite
• c) Grasshopper
• d) Thrips

44. What is the mode of action of pyrethroid insecticides?

• a) Disruption of photosynthesis
• b) Inhibition of acetylcholinesterase
• c) Disruption of sodium channels
• d) Inhibition of respiration

45. What is the recommended method to manage weed infestation in upland vegetables?

• a) Pre-emergence herbicide only
• b) Manual weeding only
• c) Integrated weed management
• d) Crop rotation only

46. Which type of pesticide formulation is most prone to drift during application?

• a) Granules
• b) Emulsifiable concentrate
• c) Wettable powder
• d) Aqueous spray

47. Which biological control agent is used to manage the coconut scale insect?

• a) Trichogramma spp.
• b) Aphytis lingnanensis
• c) Bracon hebetor
• d) Metarhizium anisopliae

48. Which equipment is ideal for applying herbicides in row crops?

• a) Rotary duster
• b) Knapsack sprayer
• c) Mist blower
• d) Ultra low volume sprayer

49. Which of the following is a contact herbicide?

• a) Butachlor
• b) Paraquat
• c) Pendimethalin
• d) Atrazine

50. What does “economic threshold level” (ETL) refer to in pest management?

• a) The cost of control exceeds the damage
• b) Pest population must be completely eradicated
• c) Pest population reaches a level where control action is needed
• d) Threshold where yield loss cannot be avoided

51. What pathogen causes rice blast disease?

• a) Xanthomonas oryzae
• b) Rhizoctonia solani
• c) Pyricularia oryzae
• d) Pseudomonas syringae

52. Panama disease in banana is caused by:

• a) Fusarium oxysporum f.sp. lycopersici
• b) Phytophthora infestans
• c) Fusarium oxysporum f.sp. cubense
• d) Cercospora musae

53. The most common bacterial disease in tomato is:

• a) Late blight
• b) Fusarium wilt
• c) Bacterial wilt
• d) Damping-off

54. Mango anthracnose is caused by which pathogen?

• a) Fusarium oxysporum
• b) Alternaria solani
• c) Colletotrichum gloeosporioides
• d) Xanthomonas campestris

55. What symptom is characteristic of corn downy mildew?

• a) Leaf spot
• b) Leaf shredding
• c) Root rot
• d) Blighted tassels

56. Rice tungro virus is transmitted by:

• a) Planthopper
• b) Green leafhopper
• c) Aphid
• d) Thrips

57. The disease cycle of late blight in potato involves:

• a) Seed-to-seed spread
• b) Soil-borne spores only
• c) Infected tubers and air-borne spores
• d) Insect vectors

58. What is the best cultural control for damping-off in seedlings?

• a) Deep planting
• b) Proper drainage and seed treatment
• c) Flood irrigation
• d) Using shade nets

59. What type of pathogen causes club root in crucifers?

• a) Bacterium
• b) Virus
• c) Fungus-like protist
• d) Nematode

60. Which of the following diseases is soil-borne?

• a) Rice tungro
• b) Citrus canker
• c) Fusarium wilt
• d) Anthracnose

61. Root-knot nematodes belong to which genus?

• a) Heterodera
• b) Meloidogyne
• c) Pratylenchus
• d) Ditylenchus

62. What is a typical symptom of root-knot nematode infestation in vegetables?

• a) Leaf blight
• b) Yellow stripes on leaves
• c) Gall formation on roots
• d) Wilted panicles

63. Which crop is a known host of the cereal cyst nematode (Heterodera avenae)?

• a) Tomato
• b) Maize
• c) Wheat
• d) Sugarcane

64. Which rodent species is a common pest in Philippine rice fields?

• a) Bandicota bengalensis
• b) Rattus tanezumi
• c) Mus musculus
• d) Rattus norvegicus

65. Which of the following is used as a rodenticide bait?

• a) Zinc phosphide
• b) Imidacloprid
• c) Sulfosulfuron
• d) Dimethoate

66. Which of the following practices is NOT part of Integrated Pest Management?

• a) Cultural control
• b) Chemical control
• c) Monocropping
• d) Mechanical control

67. What is the first step in implementing IPM in a farm?

• a) Chemical spraying
• b) Pest identification and monitoring
• c) Soil sterilization
• d) Use of resistant varieties

68. Which of the following is an example of cultural pest control?

• a) Crop rotation
• b) Insecticide use
• c) Use of parasitoids
• d) Use of traps

69. Trichoderma harzianum is commonly used in IPM as a:

• a) Fungicide
• b) Mycofungal antagonist
• c) Rodenticide
• d) Nematicide

70. Which concept is emphasized in IPM?

• a) Complete pest eradication
• b) Continuous pesticide use
• c) Economic injury level
• d) Total crop destruction

71. Which color code is used for the most toxic pesticide formulations in the Philippines?

• a) Red
• b) Blue
• c) Green
• d) Yellow

72. Which of the following PPE (Personal Protective Equipment) is essential when applying liquid pesticides?

• a) Cotton gloves
• b) Rubber gloves
• c) Open sandals
• d) Straw hat

73. What is the function of a surfactant in a pesticide spray solution?

• a) Reduce evaporation
• b) Improve spreading and sticking of spray on leaves
• c) Decrease toxicity
• d) Neutralize residues

74. Which pesticide formulation is most suitable for indoor residual spraying?

• a) Emulsifiable concentrate
• b) Dust
• c) Wettable powder
• d) Aerosol

75. What should be the first action in case of accidental pesticide poisoning?

• a) Induce vomiting immediately
• b) Drink plenty of water
• c) Take a cold shower
• d) Call a physician or poison control center

76. In pest forecasting, the term “ETL” stands for:

• a) Economic Threshold Level
• b) Estimated Tolerance Limit
• c) Ecological Threat Level
• d) Environmental Toxic Load

77. Which tool is most commonly used in pest surveillance programs?

• a) Tensiometer
• b) Pheromone trap
• c) Soil auger
• d) Lysimeter

78. Light traps are mainly effective for monitoring which type of pest?

• a) Aphids
• b) Whiteflies
• c) Nocturnal moths
• d) Termites

79. Degree-day models are used in pest forecasting to:

• a) Measure rainfall
• b) Estimate pest development stages based on temperature
• c) Predict pesticide degradation
• d) Estimate economic damage

80. Which of the following is a preventive approach in pest surveillance?

• a) Reactive pesticide spraying
• b) Monitoring pest population trends
• c) Collecting yield data
• d) Crop rotation

81. Under the Philippine Fertilizer and Pesticide Authority (FPA), what is the minimum training required to become a licensed pesticide applicator?

• a) Basic Applicator Training
• b) IPM Technician Course
• c) Extension Agent Certification
• d) Crop Protection Internship

82. Which Republic Act governs pesticide regulation and control in the Philippines?

• a) RA 8435
• b) RA 10068
• c) PD 1144
• d) RA 9275

83. Which government agency is primarily responsible for pesticide registration in the Philippines?

• a) DA-BAR
• b) FPA
• c) BPI
• d) DENR

84. Which of the following best defines a “restricted use pesticide”?

• a) A pesticide with limited market availability
• b) A pesticide approved only for ornamental crops
• c) A pesticide that can be applied only during rainy season
• d) A pesticide that requires trained personnel due to high toxicity or environmental risk

85. What is the maximum residue limit (MRL) primarily intended to ensure?

• a) Crop yield maximization
• b) Food safety for consumers
• c) Insect resistance control
• d) Fertilizer dosage

86. Which practice best prevents pesticide resistance development?

• a) Repeated use of same chemical group
• b) Spraying higher doses than recommended
• c) Rotation of different mode-of-action pesticides
• d) Continuous spraying regardless of need

87. Which of the following is a systemic fungicide?

• a) Propiconazole
• b) Mancozeb
• c) Sulfur
• d) Copper oxychloride

88. Which pest surveillance technique uses recorded climate and pest population data for predictions?

• a) Light trapping
• b) Forecast modeling
• c) Visual scouting
• d) Yellow sticky traps

89. “Baculovirus” is used primarily for the biocontrol of:

• a) Aphids
• b) Whiteflies
• c) Caterpillars (Lepidopteran larvae)
• d) Mites

90. What is the major purpose of the Economic Injury Level (EIL) in pest management?

• a) Determine harvest time
• b) Avoid unnecessary pesticide applications
• c) Promote crop growth
• d) Identify seed quality

91. A farmer applies a neonicotinoid insecticide on a flowering crop. Which non-target organism is most at risk?

• a) Earthworms
• b) Bees
• c) Rodents
• d) Birds

92. Which of the following is an example of a biorational pesticide?

• a) Glyphosate
• b) Bacillus thuringiensis (Bt)
• c) Chlorpyrifos
• d) Paraquat

93. Which pest management approach focuses on combining biological, cultural, and chemical tools with minimal environmental risk?

• a) Organic farming
• b) High-input agriculture
• c) Integrated Pest Management
• d) Zero-tillage cultivation

94. Which of the following is a contact insecticide with fast knockdown effect?

• a) Imidacloprid
• b) Malathion
• c) Chlorantraniliprole
• d) Pyrethrin

95. What is the first line of defense in preventing crop diseases?

• a) Fungicide application
• b) Use of resistant varieties
• c) Sanitation
• d) Crop rotation

96. Which class of herbicides inhibits photosynthesis by blocking photosystem II?

• a) Triazines
• b) Aryloxyphenoxypropionates
• c) Dinitroanilines
• d) Glycines

97. Which mycotoxin is produced by Aspergillus flavus in stored corn?

• a) Fumonisin
• b) Aflatoxin
• c) Ochratoxin
• d) Deoxynivalenol

98. In fungicide resistance management, what is the FRAC code used for?

• a) Classifying herbicides by crop safety
• b) Identifying insecticide persistence
• c) Grouping fungicides by mode of action
• d) Estimating residue levels

99. Which entomopathogenic fungus is widely used to control whiteflies and aphids?

• a) Beauveria bassiana
• b) Bacillus subtilis
• c) Metarhizium anisopliae
• d) Gliocladium virens

100. The primary goal of Integrated Disease Management (IDM) is to:

• a) Eliminate all disease-causing agents
• b) Minimize disease impact using compatible tools
• c) Depend solely on chemical control
• d) Promote natural disasters to reduce pests