WAEC SSCE - Agricultural Science - 1998

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The correct answer is "symptoms". When crop plants are attacked by diseases, they undergo a variety of physiological changes that can be observed. These changes are collectively referred to as symptoms. Symptoms may include changes in leaf color or shape, wilting, stunting, or the appearance of lesions on the plant. By identifying the symptoms, farmers or agricultural professionals can determine the type of disease that is affecting the crop and take appropriate measures to control or treat it.

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The correct function of the gizzard is grinding of food. The gizzard is a muscular organ in the digestive tract of birds that contains small stones or grits which help in grinding and crushing food particles into smaller pieces. The muscular walls of the gizzard contract and relax, squeezing and grinding the food against the grits or stones, breaking it down into smaller pieces that can be easily digested and absorbed by the bird's digestive system. This process of mechanical digestion is important for birds because they do not have teeth to chew their food like mammals. Therefore, the gizzard serves as a bird's teeth, helping to break down tough food materials such as seeds, grains, and insects.

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Rangeland management refers to the process of managing and conserving the natural resources of rangelands for sustainable use. The methods used in rangeland management include rotational grazing, good irrigation schedule, and roguing of pastures. Fertilizer application is also a management practice that can be used to improve soil fertility and increase forage production. However, overgrazing is not a method of rangeland management because it leads to the degradation of rangeland resources, such as soil erosion, loss of vegetation, and reduced biodiversity. Therefore, the answer is option A - Overgrazing.

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Gneiss is a metamorphic rock that is formed from granite. Granite is a type of igneous rock that is formed from the cooling and solidification of magma or lava. When granite is subjected to high temperatures and pressure over a long period of time, it undergoes a metamorphic process and transforms into gneiss. This process involves the rearrangement of mineral crystals within the rock, resulting in the characteristic layered structure of gneiss.

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The major pest of maize in Southern Nigeria is called "stem borer". Stem borers are insects that tunnel into the stem of the maize plant, causing damage to the plant and reducing its yield. They are common in many parts of the world and can cause significant economic losses to farmers. The stem borer larvae feed on the plant's tissue, causing wilting and stunting of growth. Adult stem borers are typically brown or gray moths that lay their eggs on the maize plant's leaves or stem. When the eggs hatch, the larvae bore into the stem and begin feeding, causing damage to the plant.

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Fumigation is a process of pest control that involves the use of chemicals in a gaseous form to eliminate pests. Among the given options, bean weevils are the insect pests of crops that are usually controlled by fumigation. Therefore, the correct answer is "bean weevil".

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If the percentage of nitrogen in ammonium sulphate fertilizer is 20%, then 20% of 500 kg will be: 20/100 x 500 kg = 100 kg Therefore, the amount of nitrogen in 500 kg of the fertilizer is 100 kg. Hence, the correct option is 4. 100 kg.

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The stoloniferous grass which spreads rapidly and forms a good ground cover is Cynodon plectostachyus. Stoloniferous means that the grass produces horizontal stems called stolons that spread along the ground, forming new plants at each node. This allows the grass to rapidly cover a large area, making it useful for ground cover. Cynodon plectostachyus is also known as "African Bermuda grass" and is commonly used for grazing livestock and erosion control.

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Peasant agriculture is typically characterized by small-scale farming operations with limited resources, which often rely on family labor as the primary source of work. Therefore, the type of labor that is commonly used in peasant agriculture is "family labor." Family labor involves the use of family members for various farming activities, such as planting, weeding, harvesting, and other related farm operations. In this type of labor, family members do not receive any salary or wages but rather share in the farm's profits or benefits. It is an essential component of peasant agriculture and helps to reduce labor costs, increase productivity, and ensure food security for the family.

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Pineapple is the crop that is propagated by suckers. Suckers are vegetative shoots that arise from the base of the mother plant and can be used to propagate a new plant. Pineapple plants typically produce many suckers, which can be removed and planted to establish a new crop. Citrus, tobacco, mango, and carrot are propagated by other methods, such as cuttings, grafting, or seeds.

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A combine harvester, also known as a combine, is a versatile machine that can be used for harvesting a variety of crops. However, among the options listed, the crop most commonly harvested using a combine harvester is rice. A combine harvester is equipped with a cutting platform that cuts the rice stalks and then separates the grain from the stalks and husks. The harvested rice is then stored in a hopper on the machine for transport. The use of a combine harvester for rice harvesting is faster and more efficient than traditional methods and can help farmers to increase their yield and profitability.

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Wastage of agricultural products during harvesting period is mainly due to inadequate storage and processing facilities. In many cases, farmers may harvest their crops but not have the proper facilities to store them until they can be sold or processed. This can lead to spoilage or damage from pests or weather, resulting in significant losses for the farmer. Without proper processing facilities, crops may also be left in the field to rot or be eaten by animals, further contributing to wastage. Therefore, the need for proper storage and processing facilities cannot be overemphasized in reducing post-harvest losses and ensuring food security.

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Soil is a complex mixture of different components that are essential for plant growth. These components include living organisms, such as bacteria and earthworms, which help in decomposing organic matter and recycling nutrients. Moisture is also an important component of soil, as it provides water for plants to absorb through their roots. Mineral matter, such as sand, silt, and clay, make up the non-living part of soil and provide nutrients for plant growth. Humus is the organic matter in soil that comes from the decomposition of plant and animal remains. However, light is not a component of soil, as it is a form of electromagnetic radiation that does not physically make up the soil itself.

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Establishment of agriculture and forestry should be given more attention in Nigeria for self-sufficiency in food production. Agriculture and forestry involve the cultivation of crops and the management of forests, respectively. Nigeria is blessed with fertile land and a favourable climate, which are ideal for agriculture and forestry. By establishing agriculture and forestry, Nigeria can increase its food production and achieve self-sufficiency in food supply. This will not only reduce the country's dependence on food imports but also create job opportunities for the people. The construction of roads, building of research centres, establishment of wildlife, and construction of fish ponds are also important, but the establishment of agriculture and forestry should be given more priority as it is essential for food security and economic growth.

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The term that best fits the definition provided is 'supply'. Supply refers to the quantity of a particular good or service that producers are willing and able to offer for sale at a particular market price over a given period of time. In this case, the focus is on the quantity of food crop available for sale, which falls under the purview of supply.

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The annual depreciation of the sprayer can be calculated using the straight-line method of depreciation. This method assumes that the asset depreciates at a constant rate over its useful life. To calculate the annual depreciation, we need to first determine the depreciable value of the sprayer. Depreciable value is the difference between the cost of the asset and its salvage value (the amount for which it is sold at the end of its useful life). Depreciable value = Cost - Salvage value Depreciable value = N2,000.00 - N1,000.00 Depreciable value = N1,000.00 Since the sprayer was used for 5 years, its useful life is 5 years. Annual depreciation = Depreciable value / Useful life Annual depreciation = N1,000.00 / 5 Annual depreciation = N200.00 Therefore, the annual depreciation of the sprayer is N200.00.

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A miracidium is a larval stage of a liver fluke. The liver fluke is a parasitic flatworm that infects the liver of various mammals, including humans. The life cycle of the liver fluke involves several stages, including the miracidium, which is released from the eggs of the fluke and infects a snail intermediate host. After undergoing several more developmental stages in the snail, the fluke is released as a cercariae, which can infect the final host, such as a cow or a human, by penetrating the skin or being ingested.

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One hectare of land is equal to 10,000 square meters (m²). Therefore, one hectare of a school farm is equal to 10,000m².

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The option that does not fit into the agricultural use of land is "mining". Agriculture is the practice of cultivating land, raising animals, and producing food, fiber, and other products to sustain human life. Mining, on the other hand, involves the extraction of minerals and other valuable materials from the earth's surface. While agriculture involves the management of land for the purpose of producing food and other agricultural products, mining does not involve the same type of land management and is not typically considered an agricultural practice.

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The property that is not associated with clay soil is "has low capillarity". Capillarity refers to the ability of soil to draw water upwards against the force of gravity. Clay soil actually has high capillarity because its small particles can hold onto water and draw it upwards. Therefore, is the correct answer.

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The provision of farm inputs to farmers by the government can best be described as a subsidy. This is because a subsidy is a financial assistance given by the government to a specific group or industry to support them and make their products more affordable to the consumers. In the case of farm inputs, the government provides support to farmers by subsidizing the cost of inputs such as fertilizers, seeds, and other necessary materials needed for farming. This helps to increase the farmers' yield and productivity, which ultimately benefits the economy as a whole.

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The act of clearing forests is termed "deforestation." It refers to the deliberate removal or destruction of trees and other vegetation from an area. Deforestation is often done to make room for agriculture, human settlements, and industrial activities. Deforestation has negative impacts on the environment, such as soil erosion, loss of biodiversity, and increased greenhouse gas emissions.

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Layers mash should contain a high percentage of calcium. This is because calcium is a vital mineral that is essential for eggshell formation in poultry. Laying hens require a sufficient amount of calcium in their diet to lay eggs with strong, hard shells. Calcium deficiency in hens can lead to soft-shelled or shell-less eggs, which are prone to breakage and can cause health problems for the birds. Therefore, it is important to provide layers with a diet that is rich in calcium, typically provided in the form of calcium carbonate.

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Cow dung is usually added to a fish pond in order to encourage the growth of phytoplankton and zooplankton. Cow dung contains nutrients such as nitrogen, phosphorus, and potassium, which are essential for the growth of algae and other aquatic plants. These aquatic plants form the base of the food chain in a fish pond by providing a source of food for zooplankton, which in turn are eaten by small fish, and so on up the food chain. Therefore, adding cow dung to a fish pond can help increase the amount of phytoplankton and zooplankton in the water, ultimately leading to a healthier and more productive fish population.

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The system of growing arable crops at the early stage of forest establishment is referred to as the "Taungya System". This system involves the clearing of forest land for the purpose of establishing new forests. However, during the early stage of forest establishment, farmers are allowed to plant crops such as maize, cassava, and yams in between the newly planted trees. This helps to reduce the cost of establishing a new forest while also providing income for the farmers. The crops are usually grown for a few years until the trees have grown enough to provide sufficient shade, after which the farmers are required to stop planting crops and focus solely on tending the trees. The system is named after a practice used in Myanmar (formerly Burma) and is now widely used in many tropical countries.

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The correct answer is "latex". The rubber tree is a major source of natural rubber latex, which is harvested by making small incisions in the bark of the tree and collecting the sap that flows out. Latex is a milky liquid containing a complex mixture of organic compounds, including rubber hydrocarbons, proteins, sugars, and various other substances. It is used to produce a wide variety of rubber products, such as tires, gloves, balloons, and medical equipment.

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The major advantage of drainage in agriculture is removing excess water from the soil. Drainage helps to prevent water-logging which can lead to a reduction in crop yield or even crop failure. When there is excess water in the soil, it displaces the air in the soil pores, leading to the death of plant roots due to lack of oxygen. Drainage helps to create a balance between water and air in the soil, which promotes healthy plant growth. Additionally, excess water in the soil can lead to the leaching of nutrients, making them unavailable to plants. Drainage can help to prevent this by allowing water to move through the soil, carrying nutrients to the root zone where they are needed.

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The mating of different breeds of animals is known as cross-breeding. Cross-breeding involves mating individuals from different breeds, resulting in offspring that exhibit a combination of traits from each parent breed. This is often done to produce animals with desirable characteristics, such as increased milk or meat production, improved disease resistance, or better temperament. Cross-breeding is also important for genetic diversity and can help to prevent inbreeding depression.

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Guinea grass can be propagated mainly by roots and seeds. Guinea grass (Panicum maximum) is a tropical grass widely used for grazing livestock in many parts of the world. It is known for its high yield, high protein content, and tolerance to a range of environmental conditions. Guinea grass can be propagated by root splits and seeds, making it relatively easy to establish in pastures. The other grasses mentioned in the options may also have some capacity for vegetative propagation, but they are primarily propagated by other means, such as stolons or rhizomes.

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The major raw material of the paper industry is pulp. Pulp is made by separating the cellulose fibers from the other components of wood, such as lignin and hemicellulose, through a process called pulping. The cellulose fibers are then processed further to make different types of paper products. Other raw materials like recycled paper and non-wood fibers can also be used in making pulp, but wood pulp is the primary raw material for the paper industry.

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Compost is an organic manure. Organic manure is a type of fertilizer made from natural sources, such as animal or plant materials. Compost is made by decomposing organic waste such as food scraps, leaves, grass clippings, and manure. It is rich in nutrients that plants need to grow, such as nitrogen, phosphorus, and potassium. Compost is often used to improve soil fertility and structure, as well as to retain moisture in the soil.

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The particle size of silt is 0.002 mm - 0.02 mm. This means that silt particles are smaller than sand particles (which are 0.02 mm - 2 mm) but larger than clay particles (which are smaller than 0.002 mm). Silt particles are often considered ideal for soil fertility because they are small enough to increase soil porosity and water-holding capacity, but not so small that they easily compact and reduce soil aeration.

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A goat's stomach has four compartments, which are the rumen, reticulum, omasum, and abomasum. The correct sequence of the components of a goat's stomach is rumen-reticulum-abomasum-omasum. This is because when a goat eats, the food goes into the rumen and reticulum, where it is fermented and partially digested. The food is then regurgitated and chewed again before being swallowed and sent to the omasum for further digestion and absorption of nutrients. Finally, the remaining digesta enters the abomasum, which is the true stomach, where it is mixed with acid and digestive enzymes to complete the process of digestion.

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The foot and mouth disease of cattle is caused by a virus. The foot and mouth disease is a highly contagious viral disease that affects cattle and other cloven-hoofed animals such as sheep, goats, and pigs. The virus is spread through direct contact with an infected animal or contact with contaminated objects or surfaces. It affects the animals by causing blisters and sores on their mouth, feet, and teats, which leads to fever, lameness, and reduced milk production. The virus can survive for long periods in contaminated soil, water, and manure. There is no cure for the disease, but vaccination is available for prevention.

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The correct option is "high feed intake." High environmental temperature has several negative effects on dairy cows, including fever, high water intake, low milk production, and restlessness. Heat stress caused by high temperatures can lead to decreased milk yield, reduced fertility, and increased susceptibility to diseases. In response to high temperatures, cows may also reduce their feed intake, which can further decrease milk production and cause weight loss. Therefore, high feed intake is not an effect of high environmental temperature on dairy cows.

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The symptom that occurs when there is a deficiency of iron and copper in livestock rations is anemia. Anemia is a condition where the body does not have enough red blood cells or hemoglobin, which are responsible for carrying oxygen to the body's tissues. Iron and copper are essential minerals that are required for the production of hemoglobin. A deficiency of these minerals can result in anemia, which can cause reduced growth rate and weakness in livestock. Rickets is a condition caused by a deficiency of vitamin D, which can result in weakened and deformed bones. Scaly skin and lameness are not typically associated with deficiencies of iron and copper.

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The group of farm equipment that uses electricity as their source of power includes milking machine, incubator, and refrigerator. Milking machines are used to extract milk from animals using vacuum pressure, and they require a power source to run the vacuum pump. Incubators are used for hatching eggs and require electricity to maintain the appropriate temperature and humidity levels. Refrigerators are used for preserving agricultural produce and require electricity to run the compressor that maintains low temperatures inside the refrigerator. Therefore, options A is the correct answer.

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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.

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(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.

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(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).

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(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

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None

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None

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(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.

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(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)

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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

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(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.