WAEC SSCE - Agricultural Science - 1998 (Essay)

(a) Three effects of maize weevil on maize grains

1. It bores holes into the grains and eats the endosperm, reducing the quantity and weight of the grains.
2. It lowers the quality, market value and viability (germination) of the seeds.
3. Its feeding and faeces cause heating, moulding and contamination of the stored grains.

(b) Five general control measures of insect pests of grains in storage

1. Proper drying: dry the grains well to a low moisture content before storage to discourage pests.
2. Use of insecticides: treat grains with approved storage insecticides/dusts.
3. Fumigation: fumigate the store with chemicals such as phostoxin in an airtight room.
4. Good store hygiene: keep the store clean, dry and airtight, and remove old infested stock before storing new grains.
5. Use of resistant varieties and proper containers: store in airtight silos/bins and use hermetic bags, and inspect grains regularly.

(c) Vector for each crop disease

Terms in farm management

(a) Farm valuation

Farm valuation is the process of estimating in money terms the total worth (value) of all the assets on a farm, such as land, buildings, machinery, livestock, crops and stored produce, at a particular point in time. It is used to determine the capital of the business and to prepare the balance sheet.

(b) Cash analysis account

A cash analysis account is a farm record that shows all the cash receipts (income) and cash payments (expenses) of the farm business, arranged and analysed under different headings or items over a period. It helps the farmer to see the sources of income and how money was spent.

(c) Profit and loss account

A profit and loss account is a financial statement that summarises the total income (revenue) and total expenses of the farm business over a period (usually one year), so as to show whether the farm made a profit or a loss. A profit is made when income exceeds expenses; a loss occurs when expenses exceed income.

(d) Balance sheet

A balance sheet is a statement that shows the financial position of the farm business at a particular date by listing its assets (what it owns) on one side and its liabilities (what it owes) and capital/net worth on the other. The two sides must balance, since assets equal liabilities plus the owner's capital.

(a) Farm mechanisation

Farm mechanisation is the use of machines, engines and other mechanical devices (such as tractors, ploughs, planters, harvesters and sprayers) in place of human and animal power to carry out farm operations more quickly and efficiently.

(b) Seven advantages of farm mechanisation

1. It saves time and speeds up farm operations.
2. It reduces the drudgery of manual labour.
3. It makes large-scale farming possible by cultivating large areas.
4. It reduces the cost of production per unit in the long run.
5. It increases output and productivity of the farm.
6. It ensures timely performance of operations such as planting and harvesting.
7. It reduces the problem of labour shortage.

Seven disadvantages of farm mechanisation

1. High cost of purchasing the machines.
2. High cost of fuelling, maintenance and repairs.
3. It causes unemployment by displacing farm workers.
4. It requires skilled operators who may not be available.
5. It causes soil compaction and can damage soil structure.
6. Machines are not suitable for small, scattered or steep/rocky farms.
7. It can lead to soil erosion when large areas are cleared and left bare.

(a) Bush burning

Bush burning is the setting of fire to natural vegetation or crop residues on a piece of land, usually to clear it for farming or hunting. It is a cheap and quick way of clearing land and destroys some weeds and pests. However, it has serious harmful effects: it destroys soil organisms and organic matter, reduces soil fertility, exposes the soil to erosion, destroys wildlife and its habitat, and pollutes the air. Because of these effects, bush burning is generally discouraged in good farming.

(b) Clean clearing

Clean clearing is the complete removal of all vegetation, stumps and roots from a piece of land, leaving the soil surface bare before cultivation. It gives a clean seed bed and makes mechanised operations easier. Its disadvantage is that it leaves the soil exposed to the direct impact of rain and sun, leading to loss of organic matter, leaching and severe soil erosion. It is best combined with cover cropping or mulching to protect the soil.

(c) Organic manuring

Organic manuring is the application of manures obtained from plant and animal remains (such as farmyard manure, compost, green manure and poultry droppings) to the soil to improve its fertility. It supplies plant nutrients slowly, adds humus, improves soil structure, water-holding capacity and aeration, and encourages the activity of beneficial soil organisms. It is cheaper than inorganic fertiliser and has a long-lasting effect, though it is needed in large quantities and its nutrient content is low and not precisely known.

(a) Four factors of soil formation

1. Parent material: the type of rock from which the soil is formed determines the mineral composition, texture and colour of the resulting soil.
2. Climate: rainfall and temperature control the rate of weathering; heavy rain and high temperature speed up rock breakdown and leaching.
3. Living organisms (biota): plants, animals and micro-organisms add organic matter, aid weathering and mix the soil, forming humus.
4. Topography (relief): the slope of the land affects drainage, erosion and the depth of soil that forms; and time, since soil development takes many years.

(b) Four chemical processes in the weathering of rocks

1. Oxidation
2. Hydrolysis
3. Hydration
4. Carbonation (and solution)

(a) Ration

A ration is the total amount of feed (food) given to a farm animal in a period of 24 hours to meet its nutritional needs.

(b) Four classes of livestock feed and two characteristics of each

Difference between maintenance and production rations

A maintenance ration is the amount of feed needed to keep an animal alive and in good health, without any gain or loss in body weight and without any production. A production ration is the extra feed given, over and above the maintenance ration, to enable the animal to produce (grow, fatten, work, give milk, lay eggs or reproduce).

This question tests your understanding of agricultural marketing, which covers all the activities that move farm produce from the farmer to the final consumer. Marketing is not simply "selling"; it includes assembling, transporting, storing, processing, grading and financing the produce along the way. The people and firms that carry out these functions are the marketing agents, and most of them fall under the broad name middlemen. Keep the three parts distinct: part (a) wants named agents, part (b) wants the value middlemen add, and part (c) wants the obstacles that make marketing difficult in Nigeria.

(a) Four marketing agents for agricultural products

1. Wholesalers - they buy produce in large quantities and sell in bulk to retailers.
2. Retailers - they buy from wholesalers and sell in small quantities directly to the final consumer.
3. Commission agents (brokers) - they buy and sell on behalf of others and earn a commission rather than owning the goods.
4. Assemblers (bulking agents) - they gather small lots of produce from many scattered farmers into large marketable quantities.

Co-operative marketing societies and produce merchants are also acceptable named agents.

(b) Four importance of middlemen in agricultural marketing

Farmers usually produce in small, scattered lots and lack the time, capital and reach to sell directly to distant consumers. Middlemen bridge that gap, and each of the following functions explains why they are valuable rather than merely "extra hands taking a profit":

1. Bulking (assembling): they collect the small quantities produced by many separate farmers and combine them into large, economical lots that traders and processors can handle. Without this, no single farmer produces enough to reach a big market efficiently.
2. Transportation: they move produce from remote farming areas to the towns and city markets where demand and higher prices exist, relieving the farmer of transport cost and risk.
3. Storage: they hold produce after harvest and release it gradually, so that seasonal crops remain available all year round and prices are stabilised between harvest and lean seasons.
4. Market information, credit and processing: they inform farmers about prices and demand, often advance credit before harvest, and may process, grade or package produce, thereby linking producers efficiently to consumers.

(c) Eight problems of agricultural marketing in Nigeria

1. Poor transport and road network, especially poor rural feeder roads, which raise cost and delay delivery.
2. Inadequate storage facilities, leading to heavy post-harvest losses.
3. High perishability of many products (fruits, vegetables, milk, meat), which spoil quickly before sale.
4. Price fluctuation and instability, so farmers cannot predict or plan their income.
5. Too many middlemen, each taking a margin and reducing the farmer's final share of the price.
6. Lack of grading and standardisation, making it hard to price produce fairly or trade at a distance.
7. Inadequate market information and poor market infrastructure, so farmers sell blindly and are easily cheated.
8. Inadequate processing facilities and lack of credit or finance for marketing operations.

Other acceptable points include seasonal and bulky nature of produce, illiteracy of farmers, and poor packaging.

Examination takeaway: in part (b) do not merely list the functions - add the short reason each one matters, because the command word is "discuss briefly", which earns the discussion mark. In parts (a) and (c) a clean list of correctly named, distinct points is enough; avoid repeating the same idea in two different words, since a repeated point earns only one mark.

(a) Seven reasons for good housing in poultry management

1. To protect the birds from harsh weather (rain, sun, cold and wind).
2. To protect the birds from predators and thieves.
3. To provide comfort and reduce stress, promoting good growth and egg production.
4. To make feeding, watering and general management easy.
5. To control and prevent the spread of pests and diseases.
6. To provide clean, laying nests and so keep eggs clean and reduce breakage.
7. To make it easy to collect eggs, droppings and to isolate sick birds.

(b) Nine essential features of a poultry deep litter house

1. Concrete floor: smooth, easy to clean and covered with litter material such as wood shavings.
2. Litter material: a deep layer of dry litter (wood shavings, sawdust or straw) spread on the floor.
3. Adequate ventilation: wire-mesh sides and openings to allow free flow of air.
4. Good roofing: leak-proof roof that keeps out rain and provides shade.
5. Correct orientation and spacing: sited to allow light and air, with enough floor space per bird.
6. Feeders and drinkers: adequate feeding troughs and waterers provided.
7. Laying nests: clean nesting boxes provided for laying birds.
8. Perches/roosts: provided for the birds to rest.
9. Wire-mesh/half walls and rat guards: to keep out predators and vermin, plus a foot dip at the entrance for biosecurity.

(a) Contributions of three Government agricultural programmes to the development of agriculture in Nigeria

(i) Agricultural Development Projects (ADPs)

1. Provide farm inputs such as improved seeds, fertilisers and agro-chemicals to farmers.
2. Offer extension services and training that spread improved farming techniques.
3. Construct rural roads, boreholes and storage facilities in farming areas.
4. Give farmers access to credit and to improved markets, raising output and income.

(ii) River Basin and Rural Development Authorities

1. Construct dams and provide water for irrigation, extending farming into the dry season.
2. Supply water for domestic and livestock use and control flooding.
3. Develop rural infrastructure such as roads and electricity.
4. Encourage large-scale food and fish production and generate hydro-electric power.

(iii) Agricultural Research Institutes

1. Develop improved, high-yielding and disease-resistant crop varieties and livestock breeds.
2. Discover better methods of pest, disease and soil-fertility management.
3. Train personnel and produce foundation/breeder seeds and planting materials.
4. Pass research findings to farmers through extension, increasing productivity.

(b) Four agro-based industries in Nigeria and their raw materials

Production of cocoa

(a) Method of propagation

Cocoa is propagated sexually by seeds and can also be propagated vegetatively by budding, grafting or cuttings. The seeds are first raised in a nursery before transplanting.

(b) Climatic and soil requirements

• Climate: hot, humid conditions; temperature of about 21 to 32 degrees Celsius; rainfall of about 1000 to 1500 mm well distributed; high relative humidity and shade, especially when young.
• Soil: deep, well-drained, fertile loamy soil rich in organic matter with a slightly acidic pH.

(c) Nursery requirement

Fresh, viable seeds are sown in polythene bags or seed beds filled with rich topsoil, provided with shade, watered regularly and protected from pests and diseases. Seedlings are raised for about four to six months before transplanting to the field.

(d) Maturity period

Cocoa begins to bear fruit (pods) about three to five years after transplanting and reaches full/economic bearing at about five to seven years.

(e) Method of harvesting

Ripe pods are harvested by cutting them from the tree with a sharp cutlass or a harvesting hook/knife on a pole, taking care not to damage the flower cushions. The pods are then broken open and the beans removed, fermented and dried.

(f) Two major diseases and their control