WAEC Agricultural Science 2002 past questions

Checked by the Skolra question team · Last updated 23 October 2026

Ten questions from the 2002 WAEC Agricultural Science paper, with answers and explanations. We hold 50 questions from this paper, and the Skolra app has all of them.

WAEC Agricultural Science 2002 questions and answers

1. 1.The most important factor that limits agricultural production in West Africa is
   1. A
      Unfavourable climatic conditions
   2. B
      Shortage of farm labour
   3. C
      Inadequate capital for investment
   4. D
      The land tenure system
      Correct
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   Answer: D

   The land tenure system is the most important factor limiting agricultural production in West Africa. Under the traditional (communal/family) land tenure system, land is inherited and shared among family members over generations, so individual holdings become small, scattered and fragmented. This makes it difficult to practise large-scale, mechanized farming, and because the land is not individually titled, a farmer cannot use it as collateral to obtain loans from banks. It also discourages farmers from making long-term investments, such as building irrigation works or permanent tree crops, since they are not always sure of continued use of a particular plot.

2. 2.Which of the following is not an effect of water-logging on crop production?
   1. A
      Increased soil aeration for root respiration
      Correct
   2. B
      Leaching of plant nutrients from the soil
   3. C
      Stunted growth and reduced crop yield
   4. D
      Death of plant roots due to lack of oxygen
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   Answer: A

   Water-logging occurs when soil pores become filled with water, driving out the air that plant roots and soil organisms need.

   So leaching of nutrients, death of roots from oxygen shortage, and stunted growth/reduced yield are all genuine effects of water-logging. The statement that soil aeration increases is the opposite of what actually happens, so it is the one that is not an effect of water-logging.

3. 3.Parturition in farm animals marks the end of
   1. A
      Gestation period
      Correct
   2. B
      Lactation period
   3. C
      Weaning period
   4. D
      Oestrus cycle
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   Answer: A

   Parturition is the act of giving birth (calving, lambing, farrowing, foaling, etc.) in farm animals. It is the process by which a mature foetus and the afterbirth are expelled from the uterus.

4. 4.Mealy bug is a major pest of
   1. A
      Maize
   2. B
      Cassava
      Correct
   3. C
      Citrus
   4. D
      Cowpea
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   Answer: B

   Cassava is correct. The mealybug (Phenacoccus manihoti) is a sap-sucking insect pest that attacks the shoot tips and leaves of the cassava plant, causing stunted growth, leaf curling ("bunchy top") and heavy yield loss. It was accidentally introduced into Africa from South America in the 1970s and spread rapidly across cassava-growing countries including Nigeria, becoming one of the most devastating pests of the crop until it was brought under control through the release of a natural enemy, the parasitic wasp Epidinocarsis (Anagyrus) lopezi, in a classic biological control programme.

5. 5.The daily maintenance practice carried out on a disc harrow is
   1. A
      Painting the frame to prevent rust
   2. B
      Cleaning the discs of soil and plant debris after use
      Correct
   3. C
      Sharpening the disc blades
   4. D
      Greasing the bearings and moving parts
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   Answer: B

   Maintenance of farm implements like the disc harrow is graded by how often it must be done:

   Daily (after every day's use): the discs and frame must be cleaned of soil, mud and plant trash. Left on overnight, this debris holds moisture against the metal and causes rust, and dried mud on the discs reduces their cutting efficiency the next time the implement is used. This is why cleaning the discs is the correct answer to a question asking for the daily practice.

6. 6.Which of the following sources of water is least useful for irrigation purposes?
   1. A
      Well water
   2. B
      River water
   3. C
      Sea water
      Correct
   4. D
      Rain water
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   Answer: C

   Sea water is least useful for irrigation. Irrigation water must be low in dissolved salts; sea water contains a very high concentration of salt (sodium chloride and other minerals) which, when applied to farmland, causes salt build-up in the soil, damages soil structure, and scorches or kills crop roots through osmotic stress. Very few crops can tolerate it without expensive desalination first.

   So among the choices, only sea water is unsuitable — making it the least useful source for irrigation purposes.

7. 7.Which of the following is not a characteristic of pigs?
   1. A
      High prolificacy (large litter size)
   2. B
      Short gestation period of about 114 days
   3. C
      Omnivorous feeding habit
   4. D
      Chewing of the cud (rumination)
      Correct
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   Answer: D

   The pig is a monogastric (non-ruminant) animal — it has a simple, single-chambered stomach, unlike cattle, sheep and goats which are ruminants with a four-chambered stomach. Only ruminants chew the cud (bring back swallowed food to re-chew it). Chewing of the cud is therefore not a characteristic of pigs, which is why it is the correct answer to "which is NOT a characteristic."

8. 8.Which of the following sources of farm power is most flexible and adaptable to farm operations?
   1. A
      Human power
      Correct
   2. B
      Animal power
   3. C
      Electrical power
   4. D
      Mechanical power
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   Answer: A

   Human power is correct. Of all the sources of farm power, human (manual) labour is the most flexible and adaptable because a person can move easily to any part of the farm - flat land, sloppy land, swampy or terraced land, or tiny plots - and can switch instantly between different operations such as planting, weeding, harvesting, and handling delicate produce without needing fuel, special training, or heavy equipment.

9. 9.The following are biting and chewing insects except
   1. A
      Beetle
   2. B
      Aphid
      Correct
   3. C
      Grasshopper
   4. D
      Cockroach
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   Answer: B

   Insect pests are grouped by the type of mouthparts they use to feed, and this determines the kind of damage they cause to crops.

   So among the options, the aphid is the odd one out — it does not belong with the biting and chewing insects.

10. 10.Which of the following plant diseases is not caused by fungi?
    1. A
       Swollen shoot disease of cocoa
       Correct
    2. B
       Smut of maize
    3. C
       Black pod disease of cocoa
    4. D
       Leaf spot of groundnut
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    Answer: A

    Swollen shoot disease of cocoa is the one not caused by fungi. It is a viral disease, caused by the Cacao Swollen Shoot Virus (CSSV), which is spread from tree to tree by mealybugs feeding on the plant. The symptoms are swelling of the stem and roots, yellowing of leaf veins, and die-back — nothing like a fungal infection, which usually shows up as spots, rot, moulds or powdery growth.

The questions come from past JAMB, WAEC and NECO papers. We use software to help write the answer options and explanations, and every answer is checked twice before it goes on the site. How we check

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