AGR 001: Agronomy and Crop Production
Question 1
1a(i) Define the term pest. (1 mark)
A pest is any organism (insect, animal, or microorganism) that causes damage, injury, or economic loss to crops, stored produce, or livestock, thereby reducing yield or quality.
1a(ii) State two types of mouth parts possessed by insect pests and one example each. (3 marks)
| Mouth part type | Example insect |
|---|---|
| Biting and chewing mouth parts | Grasshopper |
| Piercing and sucking mouth parts | Aphid (or cotton stainer) |
1a(iii) Highlight two effects of insect pests on crop plants and two methods of control. (3 marks)
Effects:
- Reduction in crop yield/quality through feeding damage (defoliation, boring into stems/fruits).
- Transmission of plant diseases (viruses, bacteria, fungi) from infected to healthy plants.
Methods of control:
- Chemical control — application of appropriate insecticides.
- Cultural control — crop rotation, early planting, or field sanitation to break pest life cycles.
1b. Draw and label a diagram of maize weevil and state its scientific name. (3 marks)
Scientific name: Sitophilus zeamais
Diagram description (to be hand-drawn): an oval-shaped beetle body divided into three regions —
- Head, extended forward into a long, slender snout (rostrum) bearing the mouthparts and a pair of elbowed antennae
- Thorax, roughened/pitted with small round pits, bearing three pairs of legs
- Abdomen/wing covers (elytra), hardened forewings usually marked with two pale reddish-brown spots, covering the membranous hindwings
Question 2
2a(i) Define the term weed. (½ mark)
A weed is any plant growing where it is not wanted, competing with cultivated crops for nutrients, water, light, and space.
2a(ii) Explain two methods of weed dispersal in agriculture. (2 marks)
- Wind dispersal — light seeds with hairy or winged structures (e.g., Tridax, Ageratum) are carried by wind currents to new areas.
- Agents such as farm tools, animals, and man — seeds attach to farm implements, animal fur, or are carried in contaminated crop seeds, manure, or irrigation water and spread when these are moved between fields.
2a(iii) In a tabular form, identify five common weeds in the farm stating their scientific and common names. (5 marks)
| S/N | Common name | Scientific name |
|---|---|---|
| 1 | Nut grass | Cyperus rotundus |
| 2 | Goat weed | Ageratum conyzoides |
| 3 | Spear grass | Imperata cylindrica |
| 4 | Siam weed | Chromolaena odorata |
| 5 | Water grass/ Carpet grass | Axonopus compressus |
2b. Explain elaborately, the chemical method of weeds control. (2½ marks)
Chemical weed control involves the use of chemical substances called herbicides to kill or suppress the growth of weeds. Herbicides may be:
- Selective, killing only certain plant types (e.g., broadleaf weeds) while sparing the crop (e.g., 2,4-D used in cereal fields), or non-selective, killing all vegetation it contacts (e.g., glyphosate/paraquat).
- Contact herbicides, which kill only the plant parts they touch, or systemic/translocated herbicides, which are absorbed and moved through the plant’s vascular system to kill the whole plant, including roots.
- Applied as pre-emergence (before weed seeds germinate, forming a chemical barrier in the soil) or post-emergence (applied after weeds have emerged and are actively growing).
Advantages include speed of application over large areas and effectiveness against weeds that are difficult to control mechanically. Care must be taken with dosage, timing, and weather conditions to avoid crop injury, soil/water contamination, and development of herbicide-resistant weed populations.
AGR 002: Animal Science and Production
Question 3
3a. Differentiate between the following:
(i) Testosterone and oestrogen (2 marks)
Testosterone is the primary male sex hormone, produced mainly by the testes (Leydig cells); it stimulates development of male secondary sexual characteristics and sperm production. Oestrogen is the primary female sex hormone, produced mainly by the ovarian follicles; it stimulates development of female secondary sexual characteristics and controls the oestrus cycle.
(ii) Progesterone and oxytocin (2 marks)
Progesterone is produced by the corpus luteum (and placenta in pregnancy); it maintains pregnancy by preparing and sustaining the uterine lining and suppressing further ovulation. Oxytocin is produced by the posterior pituitary gland; it causes contraction of the uterus during parturition and stimulates milk let-down (ejection) during lactation.
(iii) Relaxin and placental hormones (2 marks)
Relaxin is a hormone produced mainly by the corpus luteum/ovary (and placenta) that relaxes the pelvic ligaments and softens/dilates the cervix to ease parturition. Placental hormones (e.g., placental lactogen, oestrogens, progesterone from the placenta) are hormones secreted by the placenta during pregnancy to maintain gestation, support foetal growth, and prepare the mammary gland for lactation.
3b. Draw and label the urinogenital system of a male rabbit. (4 marks)
Diagram description (to be hand-drawn), showing the following labelled parts in sequence:
- Kidneys (paired, bean-shaped, produce urine)
- Ureters (carry urine from kidneys to bladder)
- Urinary bladder (stores urine)
- Testes (paired, in the scrotum; produce sperm and testosterone)
- Epididymis (attached to each testis; stores and matures sperm)
- Vas deferens (sperm duct carrying sperm from epididymis)
- Seminal vesicles, prostate gland, Cowper’s (bulbourethral) glands (accessory glands adding seminal fluid)
- Urethra (common passage for urine and semen, running through the penis)
- Penis (copulatory organ, terminal end of the urethra)
Question 4
4a. In an incubator, 1,500 eggs were set. During candling, 185 were unfertilized. At hatching, 644 were females and the rest were males.
Working:
- Total eggs set = 1,500
- Unfertilized eggs = 185
- Fertilized eggs = 1,500 − 185 = 1,315
- Female chicks = 644
- Male chicks = 1,315 − 644 = 671
i. % Unfertilized eggs
= (185 ÷ 1,500) × 100 = 12.33%
ii. % Fertilized eggs
= (1,315 ÷ 1,500) × 100 = 87.67%
iii. % Male chicks
= (671 ÷ 1,500) × 100 = 44.73%
iv. % Female chicks
= (644 ÷ 1,500) × 100 = 42.93%
(Check: 12.33% + 87.67% = 100%; 44.73% + 42.93% = 87.66% ≈ 87.67%, consistent with the fertilized-egg percentage.)
4b. Explain briefly the roles of the following in poultry production:
(i) Temperature (3 marks)
Temperature is critical for embryo development during incubation (optimum ≈ 37.5°C) — too high or too low reduces hatchability and causes deformities. After hatching, chicks (which cannot regulate their own body temperature well) need brooder heat (about 32–35°C, reduced gradually) to stay warm, aid digestion, feed intake, and prevent chilling, huddling, and mortality.
(ii) Relative humidity (3 marks)
Relative humidity (ideally ~55–65% during incubation, raised to ~65–70% just before hatching) controls the rate of moisture loss from the egg through the shell pores. Too low humidity causes excessive water loss, sticky chicks, and difficulty breaking the shell; too high humidity prevents adequate moisture loss, leading to large, weak chicks that drown in fluid or fail to hatch properly. Proper humidity also affects air cell size and hatch timing.
AGR 003: Wildlife, Aquaculture and Agro-forestry
Question 5
5a. Define the term desertification. (2 marks)
Desertification is the process by which fertile land progressively becomes degraded and turns into desert-like, unproductive land, typically as a result of drought, deforestation, or unsuitable/inappropriate agricultural practices.
5b. State four factors that can lead to desertification. (2 marks)
- Overgrazing by livestock
- Deforestation/indiscriminate bush burning
- Poor/unsustainable farming practices (e.g., continuous cropping without fallow)
- Prolonged drought and low, erratic rainfall
5c. Enumerate four damaging effects of desertification. (4 marks)
- Loss of soil fertility and vegetation cover
- Reduction in agricultural land and crop/livestock productivity
- Increased soil erosion (wind and water)
- Food shortages, famine, and displacement/migration of people
5d. List four systems of agroforestry. (2 marks)
- Taungya system
- Alley cropping/alley farming
- Home gardens
- Silvopastoral system (trees + livestock)
Question 6
6a. Explain four methods of harvesting fish. (4 marks)
- Netting — use of various nets (cast nets, gill nets, seine nets) to trap and haul fish out of water.
- Draining/dewatering the pond — the pond is drained of water, concentrating fish for easy hand-picking or netting.
- Angling (hook and line) — baited hooks and lines are used to catch fish individually, common in small-scale/artisanal fishing.
- Use of traps and basket — woven traps or baskets are set in the water to passively catch fish that swim in but cannot escape.
6b. Define the term Fishery regulation. (2 marks)
Fishery regulation refers to laws, rules, and guidelines established by government or regulatory bodies to control fishing activities (such as fishing methods, seasons, and quantities) in order to conserve fish stocks and ensure sustainable exploitation of fishery resources.
6c. Explain four fishery regulations in Nigeria. (4 marks)
- Mesh size regulation — specifying minimum net mesh sizes to prevent capture of immature/juvenile fish.
- Closed season — restricting fishing during breeding seasons to allow fish stocks to reproduce and replenish.
- Licensing of fishermen/vessels — requiring registration and permits before engaging in fishing, especially for commercial/trawler operations, to monitor and control fishing effort.
- Ban on use of harmful methods — prohibiting the use of chemicals, explosives (dynamite), or poison for fishing, which indiscriminately kill fish of all sizes and damage the aquatic ecosystem.
AGR 004: Agricultural Economics/Extension
Question 7
7a(i). Explain four channels of marketing farm produce. (4 marks)
- Producer → Consumer — direct sale from the farmer straight to the final consumer, with no middlemen.
- Producer → Retailer → Consumer — the farmer sells to retailers, who then sell in smaller units directly to consumers.
- Producer → Wholesaler → Retailer → Consumer — produce passes from farmer to a wholesaler (who buys in bulk), then to retailers, then to consumers.
- Producer → Commission agent/Cooperative → Wholesaler → Retailer → Consumer — farmers sell through agents or cooperative societies who bulk produce from many farmers before it moves further down the chain.
7a(ii). State two functions of agricultural marketing. (2 marks)
- Assembling/bulking of farm produce from scattered producers.
- Storage and preservation of produce to ensure availability and price stability across seasons.
7b(i). State two advantages and two disadvantages of cooperative society. (2 marks)
Advantages:
- Enables bulk purchase of inputs and bulk sale of produce at better prices.
- Provides easier access to credit/loans for members.
Disadvantages:
- Slow decision-making due to the need for consensus among many members.
- Possible mismanagement or lack of adequate managerial/technical expertise.
7b(ii). Mention two problems of agricultural marketing. (2 marks)
- Poor storage and transportation facilities, leading to high post-harvest losses.
- Price fluctuation/instability, often worsened by seasonal gluts and middlemen exploitation.
Question 8
8a(i). Define the term agricultural extension. (1 mark)
Agricultural extension is the process of educating and assisting farmers by transferring useful agricultural knowledge, skills, and improved technologies from research institutions to them, to improve farm productivity and living standards.
8a(ii). Mention two qualities of a good extension worker. (1 mark)
- Good communication skills.
- Sound knowledge of agricultural practices/technical competence.
8a(iii). State four functions of agricultural extension. (2 marks)
- Educating farmers on improved farming techniques and innovations.
- Disseminating research findings/information from research institutes to farmers.
- Assisting farmers in solving farm problems and decision-making.
- Organizing farmers into groups/cooperatives for better access to inputs, credit, and markets.
8b(i). Explain the roles of mass media on agricultural development in Nigeria. (3 marks)
Mass media (radio, television, newspapers, and increasingly the internet/social media) play a key role in agricultural development by rapidly disseminating information on improved farming methods, new technologies, market prices, and weather/climate updates to a large number of farmers spread over wide areas simultaneously. They create awareness of government agricultural policies and programmes, encourage adoption of innovations, and serve as a platform for farmer education even in remote areas where extension agents may not physically reach.
8b(ii). What are the three factors affecting the rate of adoption of innovation in agriculture? (3 marks)
- Characteristics of the innovation itself — e.g., its relative advantage, complexity, cost, and compatibility with existing practices.
- Characteristics of the farmer/adopter — e.g., level of education, age, farm size, income, and risk attitude.
- Socio-economic and environmental factors — e.g., availability of credit, access to extension services/information, government policy, and cultural/social norms within the community.