WAEC SSCE - Agricultural Science - 2015 (Essay)
Question 1 Report
(a) Describe the cultivation of Cowpea under the headings:
(i) soil requirement;
(ii) method of propagation;
(iii) spacing [ 3 marks ]
(b) Name one disease and two field pests of Cowpea. [ 3 marks ]
(c) State four cultural methods of controlling crop pests. [ 4 marks ]
(d) State four human activities that promote deforestation in West Africa. [ 4 marks ]
(e) Describe each of the following agro-forestry practices:
(i) alley cropping;
(ii) ley farming. [ 4 marks ]
(a) Cultivation of cowpea
(i) Soil requirement: Cowpea does best on well-drained sandy-loam soil of moderate fertility and slightly acid to neutral pH (about 5.5 to 6.5); it tolerates fairly poor soils but not waterlogged ones.
(ii) Method of propagation: It is propagated by seeds, sown directly at stake.
(iii) Spacing: About 30 cm within rows by 60 cm to 75 cm between rows (roughly 25 cm x 75 cm), 2 to 3 seeds per hole.
(b) One disease and two field pests of cowpea
Disease: cowpea mosaic (viral) disease (also bacterial blight, Cercospora leaf spot).
Field pests: pod borer (Maruca) and pod-sucking bugs (also aphids, thrips).
(c) Four cultural methods of controlling crop pests
- Crop rotation.
- Early/timely planting and use of clean/resistant seeds.
- Regular weeding and destruction of crop residues/alternate hosts.
- Correct spacing and proper field sanitation (also flooding, hand-picking).
(d) Four human activities that promote deforestation
- Bush burning and clearing of forest for farming (shifting cultivation).
- Indiscriminate logging/timber felling.
- Building of houses, roads and towns (urbanisation).
- Fuel-wood/charcoal gathering, mining and overgrazing.
(e) Agro-forestry practices
(i) Alley cropping: Growing arable/food crops in the alleys (spaces) between rows of planted trees or shrubs (usually leguminous), where the trees are periodically pruned and the prunings used as mulch/green manure to enrich the soil.
(ii) Ley farming: A system in which land is put under arable crops for some years and then under grass/pasture (ley) for grazing for some years in rotation, to restore soil fertility.
Answer Details
(a) Cultivation of cowpea
(i) Soil requirement: Cowpea does best on well-drained sandy-loam soil of moderate fertility and slightly acid to neutral pH (about 5.5 to 6.5); it tolerates fairly poor soils but not waterlogged ones.
(ii) Method of propagation: It is propagated by seeds, sown directly at stake.
(iii) Spacing: About 30 cm within rows by 60 cm to 75 cm between rows (roughly 25 cm x 75 cm), 2 to 3 seeds per hole.
(b) One disease and two field pests of cowpea
Disease: cowpea mosaic (viral) disease (also bacterial blight, Cercospora leaf spot).
Field pests: pod borer (Maruca) and pod-sucking bugs (also aphids, thrips).
(c) Four cultural methods of controlling crop pests
- Crop rotation.
- Early/timely planting and use of clean/resistant seeds.
- Regular weeding and destruction of crop residues/alternate hosts.
- Correct spacing and proper field sanitation (also flooding, hand-picking).
(d) Four human activities that promote deforestation
- Bush burning and clearing of forest for farming (shifting cultivation).
- Indiscriminate logging/timber felling.
- Building of houses, roads and towns (urbanisation).
- Fuel-wood/charcoal gathering, mining and overgrazing.
(e) Agro-forestry practices
(i) Alley cropping: Growing arable/food crops in the alleys (spaces) between rows of planted trees or shrubs (usually leguminous), where the trees are periodically pruned and the prunings used as mulch/green manure to enrich the soil.
(ii) Ley farming: A system in which land is put under arable crops for some years and then under grass/pasture (ley) for grazing for some years in rotation, to restore soil fertility.
Question 2 Report
(a) Mention three functions of a farm manager. [ 3 marks ]
(b) Use the information in the demand schedule below to answer the questions that follow.
| Price of Cowpea (Le) | Quantity demanded (kg) |
| 200 | 5 |
| 160 | 10 |
| 120 | 15 |
| 80 | 20 |
| 40 | 25 |
(i) Draw a demand curve from the schedule [ 4 marks ]
(ii) Use the demand schedule to explain the relationship between quantity demanded
and price. [ 2 marks ]
(c) State three advantages of the wholesaler in marketing of agricultural produce.
[ 3 marks ]
(d) Discuss the rinderpest disease under the following headings:
(i) two farm animals affected;
(ii) causative agent;
(iii) two symptoms;
(iv) one mode of transmission;
(v) one preventive measure. [ 6 marks ]
(a) Functions of a farm manager
- Plans and organizes farm operations, including the choice of enterprises and production programme.
- Supervises and directs farm workers and allocates duties to them.
- Keeps farm records and controls the use of capital, inputs and other farm resources.
(b)(i) Demand curve for cowpea
The demand schedule is represented below. Quantity demanded is plotted on the horizontal axis and price on the vertical axis. The plotted points are joined to form the demand curve, DD.
| Quantity demanded (kg) | 5 | 10 | 15 | 20 | 25 |
|---|---|---|---|---|---|
| Price of cowpea (Le) | 200 | 160 | 120 | 80 | 40 |
(b)(ii) Quantity demanded and price have an inverse relationship. As the price falls from Le 200 to Le 40, quantity demanded rises from 5 kg to 25 kg. Conversely, an increase in price reduces quantity demanded.
(c) Advantages of wholesalers in the marketing of agricultural produce
- They buy produce in large quantities from farmers, thereby providing a ready market for farm produce.
- They assemble, store and distribute produce to retailers, making the produce available where it is needed.
- They may bear marketing risks, such as spoilage and price fluctuations, and can provide credit to retailers or producers.
(d) Rinderpest disease
- Farm animals affected: cattle and buffaloes.
- Causative agent: rinderpest virus.
- Symptoms: high fever and severe diarrhoea, often with discharge from the eyes and nose.
- Mode of transmission: direct contact with an infected animal or its nasal discharge, saliva or faeces.
- Preventive measure: vaccinate susceptible animals and isolate infected animals from the herd.
Answer Details
(a) Functions of a farm manager
- Plans and organizes farm operations, including the choice of enterprises and production programme.
- Supervises and directs farm workers and allocates duties to them.
- Keeps farm records and controls the use of capital, inputs and other farm resources.
(b)(i) Demand curve for cowpea
The demand schedule is represented below. Quantity demanded is plotted on the horizontal axis and price on the vertical axis. The plotted points are joined to form the demand curve, DD.
| Quantity demanded (kg) | 5 | 10 | 15 | 20 | 25 |
|---|---|---|---|---|---|
| Price of cowpea (Le) | 200 | 160 | 120 | 80 | 40 |
(b)(ii) Quantity demanded and price have an inverse relationship. As the price falls from Le 200 to Le 40, quantity demanded rises from 5 kg to 25 kg. Conversely, an increase in price reduces quantity demanded.
(c) Advantages of wholesalers in the marketing of agricultural produce
- They buy produce in large quantities from farmers, thereby providing a ready market for farm produce.
- They assemble, store and distribute produce to retailers, making the produce available where it is needed.
- They may bear marketing risks, such as spoilage and price fluctuations, and can provide credit to retailers or producers.
(d) Rinderpest disease
- Farm animals affected: cattle and buffaloes.
- Causative agent: rinderpest virus.
- Symptoms: high fever and severe diarrhoea, often with discharge from the eyes and nose.
- Mode of transmission: direct contact with an infected animal or its nasal discharge, saliva or faeces.
- Preventive measure: vaccinate susceptible animals and isolate infected animals from the herd.
Question 3 Report
(a) State two advantages and two disadvantages of using biogas as a source of farm power. [ 4 marks ]
(b) Mention eight simple farm tools. [ 4 marks ]
(c) List two common storage structures and two processing structures that could be found on a farmstead in West Africa. [ 4 marks ]
(d) Explain the term denitrification. [ 2 marks ]
(e) Describe the following components of the soil:
(i) mineral matter;
(ii) organic matter. [ 4 marks ]
(a) Biogas as a source of farm power
Two advantages:
- It is a cheap, renewable source of energy made from farm/animal waste.
- It is clean and reduces pollution, and the spent slurry is a good manure.
Two disadvantages:
- It requires a fairly costly digester and technical know-how to set up.
- Gas production is slow and reduced in cold weather, and the gas is flammable/explosive if mishandled.
(b) Eight simple farm tools
Cutlass (matchet), hoe, rake, spade, shovel, axe, watering can and hand trowel (also file, sickle, garden fork, head-pan).
(c) Storage and processing structures on a farmstead
Two storage structures: barn and crib (also silo).
Two processing structures: the rice/oil mill and the grinding/processing shed (also cassava processing unit, drying floor).
(d) Denitrification
Denitrification is the process by which denitrifying bacteria break down nitrates in the soil and release free nitrogen gas back into the atmosphere, thereby reducing the nitrogen (fertility) available to plants.
(e) Components of the soil
(i) Mineral matter: The inorganic part of the soil formed from weathered rock particles (sand, silt and clay). It gives the soil its texture and supplies mineral nutrients to plants.
(ii) Organic matter: The part of the soil made up of decayed and decaying plant and animal remains (humus). It improves soil structure, water and nutrient retention, and supports soil organisms.
Answer Details
(a) Biogas as a source of farm power
Two advantages:
- It is a cheap, renewable source of energy made from farm/animal waste.
- It is clean and reduces pollution, and the spent slurry is a good manure.
Two disadvantages:
- It requires a fairly costly digester and technical know-how to set up.
- Gas production is slow and reduced in cold weather, and the gas is flammable/explosive if mishandled.
(b) Eight simple farm tools
Cutlass (matchet), hoe, rake, spade, shovel, axe, watering can and hand trowel (also file, sickle, garden fork, head-pan).
(c) Storage and processing structures on a farmstead
Two storage structures: barn and crib (also silo).
Two processing structures: the rice/oil mill and the grinding/processing shed (also cassava processing unit, drying floor).
(d) Denitrification
Denitrification is the process by which denitrifying bacteria break down nitrates in the soil and release free nitrogen gas back into the atmosphere, thereby reducing the nitrogen (fertility) available to plants.
(e) Components of the soil
(i) Mineral matter: The inorganic part of the soil formed from weathered rock particles (sand, silt and clay). It gives the soil its texture and supplies mineral nutrients to plants.
(ii) Organic matter: The part of the soil made up of decayed and decaying plant and animal remains (humus). It improves soil structure, water and nutrient retention, and supports soil organisms.
Question 4 Report
(a) In an incubator, 1,500 eggs were arranged on the trays for incubation. During candling, 25 eggs were discovered to be unfertilized. At hatching, 475 chicks were male and the remaining were female. Calculate the percentage of:
(i) unfertilized eggs;
(ii) fertilized eggs;
(iii) male chicks;
(iv) female chicks. [ 6 marks]
(b) State four signs that indicate the approach of parturition in a cow. [ 4 marks ]
(c) Mention four vegetative materials that could be used in propagating ornamental
plants. [ 4 marks ]
(d) State four advantages of grafting. [ 4 marks ]
Given: 1,500 eggs incubated; 25 unfertilized; at hatching 475 chicks were male, the rest female.
(a)(i) Percentage of unfertilized eggs
\[ \frac{25}{1500} \times 100 = 1.67\% \](a)(ii) Percentage of fertilized eggs
Fertilized eggs = 1500 - 25 = 1475.
\[ \frac{1475}{1500} \times 100 = 98.33\% \](a)(iii) Percentage of male chicks
Total chicks hatched = 1475. Male = 475.
\[ \frac{475}{1475} \times 100 = 32.2\% \](a)(iv) Percentage of female chicks
Female = 1475 - 475 = 1000.
\[ \frac{1000}{1475} \times 100 = 67.8\% \](Percentages of chicks are taken on the 1,475 eggs that hatched; if taken on all 1,500 eggs, male = 31.7% and female = 66.7%.)
(b) Four signs of approaching parturition in a cow
- Swelling/enlargement of the udder and dropping of milk (waxing of teats).
- Swelling and reddening of the vulva with mucous discharge.
- Restlessness and the cow isolating itself from the herd.
- Slackening/sinking of the pelvic (tail-head) ligaments and loss of appetite.
(c) Four vegetative materials for propagating ornamental plants
- Stem cuttings.
- Suckers.
- Bulbs/corms.
- Layers (also rhizomes, offsets).
(d) Four advantages of grafting
- The offspring is true to type and retains the good qualities of the parent.
- It brings early maturity/fruiting.
- It allows a disease-resistant or hardy rootstock to be combined with a high-yielding scion.
- It is used to propagate plants that do not produce viable seeds, and to repair damaged plants.
Answer Details
Given: 1,500 eggs incubated; 25 unfertilized; at hatching 475 chicks were male, the rest female.
(a)(i) Percentage of unfertilized eggs
\[ \frac{25}{1500} \times 100 = 1.67\% \](a)(ii) Percentage of fertilized eggs
Fertilized eggs = 1500 - 25 = 1475.
\[ \frac{1475}{1500} \times 100 = 98.33\% \](a)(iii) Percentage of male chicks
Total chicks hatched = 1475. Male = 475.
\[ \frac{475}{1475} \times 100 = 32.2\% \](a)(iv) Percentage of female chicks
Female = 1475 - 475 = 1000.
\[ \frac{1000}{1475} \times 100 = 67.8\% \](Percentages of chicks are taken on the 1,475 eggs that hatched; if taken on all 1,500 eggs, male = 31.7% and female = 66.7%.)
(b) Four signs of approaching parturition in a cow
- Swelling/enlargement of the udder and dropping of milk (waxing of teats).
- Swelling and reddening of the vulva with mucous discharge.
- Restlessness and the cow isolating itself from the herd.
- Slackening/sinking of the pelvic (tail-head) ligaments and loss of appetite.
(c) Four vegetative materials for propagating ornamental plants
- Stem cuttings.
- Suckers.
- Bulbs/corms.
- Layers (also rhizomes, offsets).
(d) Four advantages of grafting
- The offspring is true to type and retains the good qualities of the parent.
- It brings early maturity/fruiting.
- It allows a disease-resistant or hardy rootstock to be combined with a high-yielding scion.
- It is used to propagate plants that do not produce viable seeds, and to repair damaged plants.
Question 5 Report
(a) State four reasons why the prices of most agricultural produce are unstable in West
Africa. [ 4 marks ]
(b) Explain the following agricultural extension methods:
(i) method demonstration;
(ii) agricultural shows. [ 4 marks ]
(c) Discuss the cercospora leaf spot disease under the following headings:
(i) crop affected;
(ii) causative agent;
(iii) mode of transmission;
(iv) two symptoms;
(v) one preventive measure. [ 6 marks ]
(d) State four advantages of selection as a method of crop improvement. [ 4 marks ]
Question 6 Report
(a) Differentiate between land ownership by leasehold and land ownership by freehold. [ 2 marks ]
(b) Mention five ways in which non-governmental organizations contribute to agricultural
development in West Africa. [ 5 marks ]
(c) State four ways in which rural-urban migration has hindered agricultural development in West Africa. [ 4 marks ]
(d) Mention three socio-economic uses of land. [ 3 marks ]
(e) Explain two ways by which each of the following environmental factors affect agricultural production:
- Soil organisms;
- soil texture. [ 4 marks ]
(a) Leasehold versus freehold land ownership
In leasehold, an individual holds land for a fixed period on payment of rent to the owner, and the land reverts to the owner when the term expires. In freehold, the individual owns the land outright and permanently, with full title and the right to sell, lease or bequeath it.
(b) Five ways NGOs contribute to agricultural development in West Africa
- They provide credit/grants and inputs (seeds, fertilizer, tools) to farmers.
- They train farmers and offer extension/advisory services.
- They fund and sponsor agricultural research and projects.
- They help build rural infrastructure, storage and processing facilities.
- They assist in marketing produce and forming cooperatives, and give relief during disasters.
(c) Four ways rural-urban migration has hindered agricultural development
- It causes shortage of farm labour in the rural areas.
- It leaves mainly the aged and children on the farms, reducing productivity.
- It leads to abandonment of farmland and fall in food production.
- It reduces the adoption of improved practices as able-bodied, educated youths leave farming.
(d) Three socio-economic uses of land
- For building of houses, schools and hospitals.
- For recreation (parks, playgrounds) and worship.
- For siting of markets, industries and roads.
(e) Two ways each environmental factor affects agricultural production
Soil organisms:
- They decompose organic matter and release/recycle nutrients, improving fertility.
- Some (earthworms) improve aeration and drainage, while harmful ones cause plant diseases.
Soil texture:
- It determines water-holding capacity and drainage of the soil (sandy drains fast, clay holds water).
- It influences aeration, ease of tillage and root penetration, hence crop growth.
Answer Details
(a) Leasehold versus freehold land ownership
In leasehold, an individual holds land for a fixed period on payment of rent to the owner, and the land reverts to the owner when the term expires. In freehold, the individual owns the land outright and permanently, with full title and the right to sell, lease or bequeath it.
(b) Five ways NGOs contribute to agricultural development in West Africa
- They provide credit/grants and inputs (seeds, fertilizer, tools) to farmers.
- They train farmers and offer extension/advisory services.
- They fund and sponsor agricultural research and projects.
- They help build rural infrastructure, storage and processing facilities.
- They assist in marketing produce and forming cooperatives, and give relief during disasters.
(c) Four ways rural-urban migration has hindered agricultural development
- It causes shortage of farm labour in the rural areas.
- It leaves mainly the aged and children on the farms, reducing productivity.
- It leads to abandonment of farmland and fall in food production.
- It reduces the adoption of improved practices as able-bodied, educated youths leave farming.
(d) Three socio-economic uses of land
- For building of houses, schools and hospitals.
- For recreation (parks, playgrounds) and worship.
- For siting of markets, industries and roads.
(e) Two ways each environmental factor affects agricultural production
Soil organisms:
- They decompose organic matter and release/recycle nutrients, improving fertility.
- Some (earthworms) improve aeration and drainage, while harmful ones cause plant diseases.
Soil texture:
- It determines water-holding capacity and drainage of the soil (sandy drains fast, clay holds water).
- It influences aeration, ease of tillage and root penetration, hence crop growth.
