WAEC SSCE - Agricultural Science - 2009

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The twisting, wrinkling, and mottling of leaves are symptoms of viral diseases. Viruses can cause a wide range of symptoms in plants, including these visual signs on the leaves. The symptoms can vary depending on the type of virus and the plant species, but generally, viruses can cause deformations, discolorations, and patterns on leaves. Other symptoms may include stunted growth, reduced yield, and wilting. Therefore, it is essential to identify and manage viral diseases to prevent further damage to the crops.

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Edible seeds with a sticky covering and hooks are most likely to be dispersed by animals. This is because the sticky covering and hooks allow the seeds to attach to the fur or feathers of animals as they brush past, allowing the seeds to be carried away from the parent plant and dispersed over a wider area. Animals such as birds, squirrels, and other small mammals are known to disperse seeds in this way, and it is an important method of seed dispersal in many plant species. The seeds may be carried for long distances, and when they eventually fall off, they may have been transported to a new location where they can germinate and grow into new plants.

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The mechanical introduction of semen into the vagina of a female animal is called "artificial insemination." This is a process where the semen is collected from a male animal and then inserted into the reproductive tract of a female animal using special equipment such as a catheter or syringe. This method can be used to breed animals with desirable traits, improve the genetic diversity of a population, and reduce the spread of diseases. It is a common practice in animal agriculture and also used in some human fertility treatments.

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Controlled burning has the advantage of inducing re-growth of pasture grasses. This is because burning can remove dead and woody vegetation, which can accumulate over time and inhibit the growth of new grasses. By removing this vegetation, controlled burning can create open space and allow sunlight to reach the soil, promoting the growth of new grasses. In addition, burning can also stimulate the release of nutrients from the ash, which can further enhance grass growth. While controlled burning can have other benefits, such as improving soil structure and increasing the number of soil organisms, inducing re-growth of pasture grasses is one of its primary advantages and is often the reason why it is used in agriculture and rangeland management.

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Farm surveying is important because it determines the size and shape of farmland. This information is necessary for making decisions about how to use the land, such as how many crops to plant and how to lay out the fields. In addition, farm surveying can also help to identify potential problem areas, such as areas with poor drainage or erosion, which can affect soil fertility and crop yields. Overall, accurate and thorough farm surveying is essential for maximizing the productivity and profitability of a farm.

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The greatest disadvantage of using a bulldozer in land clearing is that it removes the fertile topsoil along with the vegetation. Bulldozers are very powerful machines that can clear large areas of land quickly. However, the process of bulldozing involves removing all of the vegetation, including the top layer of soil, which is the most fertile layer of the soil. This can cause the soil to become less fertile, making it more difficult to grow crops in the future. In addition, the process of bulldozing can also cause erosion, which can further degrade the soil.

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The practice of growing both food and forage crops simultaneously on the same piece of land is called ley farming. This involves planting a forage crop, such as grass or clover, alongside a food crop, such as corn or wheat. The forage crop helps to maintain soil fertility and structure by fixing nitrogen and adding organic matter to the soil, while the food crop provides a source of income for the farmer. The ley is usually grown for a period of one to three years before being plowed under and replaced with a new crop rotation. Ley farming is a sustainable and environmentally friendly farming practice that helps to maximize the productivity of the land.

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The most important contribution of agriculture to mankind is the provision of food. Agriculture is responsible for producing food crops, livestock, and fish that make up the majority of the world's food supply. Without agriculture, humans would not have access to the variety of food needed to sustain life. Agriculture also plays a critical role in ensuring food security, particularly in developing countries where access to food can be limited. Additionally, agriculture provides employment opportunities, contributes to foreign exchange earnings, and can be a source of shelter through the use of natural fibers and building materials. However, the provision of food is considered the most important contribution of agriculture to mankind.

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The correct answer is "drainage". Drainage is the removal of excess water from the sub-soil. Excess water in the sub-soil can be harmful to plant growth as it can cause waterlogging, which reduces the amount of oxygen available to the plant roots. Drainage is done by providing channels or outlets through which the excess water can flow out of the soil. This helps to improve soil aeration, soil structure, and root development, which ultimately leads to improved plant growth and higher yields. Drainage can be achieved through various methods, such as surface drainage, subsurface drainage, and vertical drainage.

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The use of land for agricultural purposes involves different activities such as crop production, livestock grazing, and fish farming. However, road construction is not considered an agricultural activity. Therefore, the answer is road construction.

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Prolonged use of sulphate of ammonia (a fertilizer containing ammonium sulfate) on a neutral soil can lead to soil acidification over time, which can adversely affect plant growth. Therefore, the fertilizer that should be applied for good plant growth in this case is one that can help neutralize the acidity of the soil. Lime is commonly used to raise soil pH, and so it is the best choice for neutralizing the acidic effects of prolonged use of sulphate of ammonia on a neutral soil. Ammonium nitrate, urea, and single superphosphate do not have the same soil pH-neutralizing properties as lime and are not effective in addressing the issue of soil acidification caused by the prolonged use of sulphate of ammonia on a neutral soil.

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The embryonic membranes of a developing embryo are the extra-embryonic membranes that surround and protect the embryo inside the egg or the uterus. These membranes include the amnion, chorion, allantois, and yolk sac. Out of the options provided, the embryonic membranes do not include the "uterus." The uterus is the organ inside the female reproductive system where the embryo implants and develops into a fetus during pregnancy. It is not an embryonic membrane, but rather the organ that provides the environment and nutrients necessary for the development of the embryo. In summary, the embryonic membranes are the extra-embryonic membranes that surround and protect the embryo during development, and they include the amnion, chorion, allantois, and yolk sac. The uterus is not an embryonic membrane, but rather the organ inside the female reproductive system where the embryo implants and develops into a fetus.

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The most important input contributed by farm family is labor. This is because farming activities require a lot of manual work, such as planting, weeding, harvesting, and other activities that require human effort. While money, implements, and fertilizers are important inputs, without labor, it would be difficult to carry out farming activities. Additionally, family labor is often more readily available and affordable compared to hired labor, making it a crucial input in small-scale farming operations.

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Hereditary characteristics are passed from parents to offspring through the gene. Genes are the basic unit of inheritance that contain DNA, which carries the genetic information that determines the traits or characteristics of an individual. During the process of reproduction, the genes from the parents are combined to form the genetic makeup of the offspring. This genetic makeup determines the physical and physiological traits of the offspring. The genes are passed down from generation to generation and can be influenced by various factors such as mutation, recombination, and environmental factors.

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The ratio of 0:10:0 written on the fertilizer bag indicates the amount of nitrogen (N), phosphorus (P), and potassium (K) in the fertilizer. The first number represents the percentage of nitrogen, the second number represents the percentage of phosphorus, and the third number represents the percentage of potassium. In this case, the ratio of 0:10:0 means that the fertilizer contains 0% of nitrogen, 10% of phosphorus, and 0% of potassium. Therefore, the correct option is: - 0 kg of nitrogen, 10 kg of phosphate and 0 kg of potash. It's important to note that the numbers in the ratio can be in any units, such as percentages or kilograms per ton. The ratio simply indicates the relative amounts of N, P, and K in the fertilizer.

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To calculate the plant population required for one hectare of land, we need to convert the hectare size to square meters. 1 hectare = 10,000 square meters Next, we need to calculate the area occupied by a single plant, given that the crop is planted at a spacing of 100cm x 50cm. Area occupied by a single plant = 100cm x 50cm = 5000 square cm We need to convert this to square meters: 5000 square cm = 0.5 square meters So, the area occupied by a single plant is 0.5 square meters. To calculate the plant population per hectare, we need to divide the total area of the hectare by the area occupied by a single plant: 10,000 square meters ÷ 0.5 square meters = 20,000 plants Therefore, the plant population required for one hectare of land with a spacing of 100cm x 50cm is 20,000. The answer is option D (20,000).

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Cows should not be allowed to eat plenty of young fresh pastures because they may develop a condition called "bloat." Bloat is a digestive disorder that occurs when gas accumulates in the rumen, which is the cow's first stomach. Young, lush pastures contain high levels of soluble protein and low levels of fiber, which can cause the cow's rumen to produce excess gas. This gas can cause the rumen to distend and put pressure on the cow's diaphragm, making it difficult for the cow to breathe. If left untreated, bloat can be fatal. To prevent bloat, cows should be introduced gradually to young, fresh pastures and given access to dry hay or straw to help balance their diet. Additionally, farmers can use management practices such as rotational grazing, limiting the time that cows spend on a particular pasture, and adding anti-bloat agents to the cow's feed. By managing their cows' diet and pasture access, farmers can prevent bloat and ensure the health and wellbeing of their herd.

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The statement that is true about a good fish pond is that "it must have low concentration of dissolved salts." Fish ponds need to maintain a certain level of salinity to support the health of fish, but if the concentration of dissolved salts is too high, it can be harmful or even fatal for the fish. High levels of dissolved salts can also affect the growth of aquatic plants and lead to an imbalanced ecosystem in the pond. Therefore, it is important to maintain a low concentration of dissolved salts in a fish pond to ensure the health and productivity of the fish.

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Mechanization refers to the use of machines in agriculture to carry out various tasks like plowing, sowing, harvesting, and threshing. Mechanization is difficult to practice where the land is fragmented. This is because mechanization requires large tracts of land to be economically viable. If the land is fragmented into small plots, it becomes challenging to use large machines, and farmers will have to rely on manual labor. The cost of acquiring and maintaining the machines is also high. On the other hand, if the farm holding is large, the cost of acquiring and maintaining the machines can be spread over a larger area, making it economically viable to practice mechanization. If the soil fertility is low, it will affect the growth and development of crops, making it difficult to use machines for farm work. In such cases, farmers will have to rely on manual labor and soil improvement practices to improve soil fertility. The wealth of the farmer is not a determinant of the practice of mechanization. However, wealthy farmers may find it easier to acquire and maintain machines for farm work.

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An advantage of commercial agriculture is that it produces high returns. This means that large scale commercial agriculture can result in high profits due to the large volume of crops produced for sale. Unlike subsistence farming, commercial agriculture is carried out on a larger scale with more advanced technology and techniques aimed at maximizing yield and profits. As a result, commercial agriculture is seen as a viable means of generating income and boosting economic growth in many countries.

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The crop that is typically harvested using a combine harvester is maize. A combine harvester is a versatile machine that is designed to harvest a variety of crops, but it is most commonly used for cereal crops like maize, wheat, and barley. The combine harvester can perform several operations at once, including cutting, threshing, separating, and cleaning the grain. This makes it a highly efficient tool for harvesting large fields of cereal crops. The other crops listed in the options, such as groundnut, cassava, and cotton, are not typically harvested using a combine harvester. Groundnuts are usually harvested manually or with the help of machines that dig up the plants and shake the pods loose. Cassava is harvested by hand, and the roots are then dug up and separated from the stems and leaves. Cotton is harvested mechanically using a cotton picker, which is a machine that removes the cotton bolls from the plants. Therefore, the answer is option A, maize.

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The question is asking for a grass that is not common in rangelands. Therefore, we need to identify the grass that is not commonly found in rangelands from the options given. - Panicum maximum, Cynodon dactylon, and Imperata cylindrical are all commonly found in rangelands. - Calopogonium mucunoides, on the other hand, is not a common grass in rangelands. Therefore, the correct answer is Calopogonium mucunoides.

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Fresh farmyard manure is not advisable to apply directly to crops because its heat of decomposition can be too high, which may lead to scorching or burning of the plants. Additionally, it may contain harmful microorganisms that could be detrimental to the plants. It is also possible for fresh manure to increase soil acidity, which could be harmful to plants that prefer neutral or alkaline soil pH. On the other hand, fresh manure does not usually increase soil alkalinity, as it generally contains more acid-forming compounds than alkaline-forming compounds.

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The equipment that is not used in farm surveying is the pick axe. Farm surveying involves taking measurements of the land and its features, and as such, equipment such as Gunter's chain, measuring tape and ranging pole are commonly used. A pick axe, on the other hand, is a tool used for digging and breaking up hard surfaces, and is not typically used in surveying agricultural land.

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Poultry showing difficulty in breathing and loss of appetite are likely under the attack of aspergillosis. Aspergillosis is a respiratory disease caused by the fungus Aspergillus. It affects the respiratory system of poultry causing difficulty in breathing and a loss of appetite. The fungus can grow on damp bedding material, feed, and dust in the poultry house. It can also spread from bird to bird through the air. If left untreated, aspergillosis can lead to death in birds.

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Magnesium deficiency in crops can be corrected by the application of dolomite. Dolomite is a type of mineral that contains both calcium and magnesium. When it is added to soil, it can increase the levels of magnesium in the soil and therefore help to correct magnesium deficiency in crops. Limestone, on the other hand, contains calcium but not magnesium, so it would not be effective in correcting magnesium deficiency. Quicklime is a form of calcium oxide that is often used to raise soil pH, but it does not contain magnesium. Urea is a nitrogen fertilizer and does not contain magnesium either, so it would also not be effective in correcting magnesium deficiency in crops.

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The natural grasslands of West Africa are generally located in the Guinea Savanna. The Guinea Savanna is a biogeographic region in West Africa that stretches across several countries, including Nigeria, Ghana, Côte d'Ivoire, Burkina Faso, and Mali. It is characterized by a mix of grassland and woodland vegetation, with scattered trees and shrubs. The region is typically found between the tropical rainforest to the south and the Sahara Desert to the north. The Guinea Savanna receives more rainfall than the Sahel region to the north, but less than the rainforest to the south. As a result, the vegetation is adapted to a seasonal climate with a long, dry season and a shorter rainy season. The grasslands of the Guinea Savanna are an important resource for the people and wildlife of the region. They provide grazing land for livestock, habitat for wildlife, and are also used for crop cultivation in some areas. In summary, the natural grasslands of West Africa are generally located in the Guinea Savanna, a biogeographic region that stretches across several countries in the region. The Guinea Savanna is characterized by a mix of grassland and woodland vegetation and is found between the tropical rainforest to the south and the Sahara Desert to the north. The grasslands are an important resource for people and wildlife in the region.

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The economic importance of forests cannot be overstated. Forests provide a wide range of resources that can be exploited for various purposes, including economic gains. These resources can be broadly categorized into four main types: timber, non-timber forest products, environmental services, and recreation. Out of the options provided, the economic resource that is not associated with forests is domestic animals. While forests provide habitats for many wild animals, they are not typically used for raising domesticated animals such as cattle, sheep, or pigs. Forests can serve as sources of medicinal plants, which can be used to develop pharmaceuticals and other medical products. They also provide habitats for game animals that can be hunted for meat or used for ecotourism. Additionally, forests are home to a variety of edible wild fruits, nuts, and other non-timber forest products that can be harvested and sold for food or other purposes. In summary, while forests may not be used for raising domestic animals, they provide a wealth of other economic resources, including medicinal plants, game animals, and non-timber forest products. They also provide valuable environmental services and recreational opportunities.

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The major cause of spoilage in fresh fish is bacterial attack. When fresh fish is harvested, it starts to spoil immediately due to the growth of bacteria on the surface and inside the fish. Bacteria present in the environment or on the equipment used during processing can also contaminate the fish. The bacteria breaks down the proteins and lipids in the fish, leading to the production of unpleasant odors and flavors, sliminess, discoloration, and other signs of spoilage. To prevent bacterial growth, fresh fish should be stored at low temperatures, preferably below 4°C, and for a short period of time.

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The atmosphere gains carbon dioxide through various natural and human activities, but one of the options listed is incorrect. Carbon dioxide is taken up by plants during photosynthesis, released into the atmosphere through respiration by plants and animals, and through the death and decay of plants and animals. Additionally, human activities such as burning fossil fuels like coal and wood for energy also release carbon dioxide into the atmosphere. Therefore, the option that is incorrect is "photosynthesis in plants" since photosynthesis actually removes carbon dioxide from the atmosphere rather than adding it.

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The ingredient that is not a major source of minerals in animal feeds is palm kernel meal. This is because palm kernel meal is mainly a source of energy and protein for animals and does not contain significant amounts of minerals. On the other hand, oyster shell, fish meal, and bone meal are all sources of minerals commonly added to animal feeds. Oyster shell is a source of calcium, fish meal is a source of phosphorus, and bone meal is a source of calcium and phosphorus.

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An individual proposing to start a farm would typically obtain estimates of yield, prices, and costs by consulting with agricultural officers or local farmers. Agricultural officers or local farmers can provide valuable information about the specific crops or livestock that the individual is planning to produce, as well as the prevailing market prices and expected yields. This information can help the individual prepare a budget and determine whether the farm is likely to be profitable. It is important to note that relying solely on past experience or trial and error may not be sufficient, as the success of a farm depends on many factors that may vary from year to year. Similarly, books written about overseas farms may not provide relevant information for the specific conditions and markets of the individual's local area.

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Zoonotic diseases are those that can be transmitted from animals to humans. These diseases can be caused by viruses, bacteria, parasites, and fungi, and can be contracted through direct contact with infected animals or their body fluids, through consumption of contaminated food or water, or through bites from infected insects. Some examples of zoonotic diseases include rabies, anthrax, Lyme disease, and avian influenza. Proper hygiene, vaccination, and control of animal populations can help prevent the spread of zoonotic diseases.

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Biological control of pests involves the use of natural enemies of pests to control their population. An example of biological control of pests is using ladybird beetles to feed on aphids, which are pests that damage crops. Ladybirds are natural predators of aphids, so introducing them into a field can help to reduce the population of aphids without the use of harmful chemicals. Therefore, the correct answer is "using lady bird beetles to feed on cytoplasm".

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Predators are not an abiotic condition that affects livestock production. Abiotic conditions are non-living factors that affect the environment, such as sunlight, rainfall, and temperature. These factors can affect the health and productivity of livestock by influencing the availability of food, water, and shelter. For example, temperature can affect the growth and reproduction of livestock, while rainfall can affect the availability of grazing land and water sources. Predators, on the other hand, are living factors, or biotic factors, that can affect livestock production by preying on the animals. While predators can certainly be a concern for livestock farmers, they are not considered abiotic conditions because they are living organisms.

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Soil formation is a complex process that involves both abiotic and biotic factors. Biotic factors refer to the living organisms that inhabit the soil, including plants, animals, and microorganisms. These biotic factors play an important role in soil formation. Of the options given, the process in soil formation that is caused by biotic factors is bacterial decomposition of plants, soil mixing and turning by earthworms, and burrowing of rodents. These processes involve the action of living organisms, which break down organic matter, mix and aerate the soil, and create channels that facilitate water infiltration and root growth. On the other hand, soil disintegration by dehydration is an abiotic process. It is caused by physical factors such as temperature, wind, and moisture. When soil dries out, it can become hard and compact, making it difficult for plants to grow. Soil disintegration by dehydration can also result in the loss of valuable topsoil through erosion.

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Establishing a grass with centrosema spp. in a pasture will result in high forage yield. This is because centrosema is a legume that can fix atmospheric nitrogen into the soil, making it available for use by the grass. This increased availability of nitrogen leads to increased growth of the grass, resulting in higher yields of forage. Additionally, centrosema has deep roots that help to break up compacted soils, improve soil structure, and reduce erosion, further contributing to the growth of the grass. Therefore, the correct answer is "forage yield will be high."

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Hermetic storage of grains means keeping grains in air-tight containers. This is a method of storing grains in which air is removed from the container or airtight bags, creating an oxygen-deficient atmosphere. This process eliminates insects and pests by suffocating them, thereby preventing the grains from being infested or contaminated by insects and pests. The hermetic storage method helps to reduce grain losses, maintain the quality of stored grains, and increase food security by preserving grains for longer periods.

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The statement that is true about mulches is that they include paper and polythene sheets. Mulches are materials that are used to cover the soil surface to enhance plant growth and reduce soil erosion. They can be organic or inorganic. Organic mulches include leaves, hay, straw, wood chips, while inorganic mulches include plastic and paper sheets. Paper and polythene sheets are examples of synthetic mulches that are used to suppress weed growth and conserve soil moisture. They are placed on top of the soil surface and prevent light penetration, thereby inhibiting the growth of weeds.

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Bush fallowing is necessitated by a reduction in soil fertility. The process of continuous cultivation of land leads to the depletion of soil nutrients, which makes it difficult for crops to grow properly. To address this, farmers practice bush fallowing, which involves leaving the land fallow for several years. During this period, the land is allowed to regenerate and restore soil fertility. The practice is also used to control pests and diseases that may have accumulated in the soil due to continuous cultivation. Therefore, the primary reason for bush fallowing is to restore soil fertility and maintain crop productivity.

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The correct answer is that deep-rooted crops should follow shallow-rooted crops in crop rotation because they feed from different soil layers. Shallow-rooted crops mostly utilize nutrients from the topsoil, while deep-rooted crops obtain nutrients from deeper soil layers. By alternating these crops in a particular field, nutrients will not be depleted from a particular soil layer, and the soil will remain healthy and productive. Additionally, the use of deep-rooted crops such as legumes can help to improve soil structure, aerate the soil, and increase water infiltration rates, which will further enhance soil health and crop productivity.

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A well fermented and dried coffee seed is said to be "graded". Grading of coffee refers to the sorting of coffee beans by size, shape, density, and color. Grading helps to ensure consistency in the quality of coffee, as beans of similar characteristics are grouped together. A well-graded coffee seed is free of defects, has a consistent size and color, and has been properly dried and fermented. This helps to produce a higher quality cup of coffee, as the beans will roast more evenly and extract more consistently during brewing.

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The sign of heat in animals refers to the period of sexual receptivity in females. During this time, the animal is ready to mate and can conceive offspring. The signs of heat in animals include restlessness and nervousness, attempting to mount other animals, and a red and swollen vulva. However, increased appetite is not a sign of heat in animals. While some animals may experience changes in their appetite during the estrus cycle, it is not considered a reliable indicator of sexual receptivity. Overall, the signs of heat in animals are important for breeders and owners to recognize in order to ensure the best reproductive outcomes for their animals.

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If a pig has only one testis, it can still produce viable sperm. This is because the testis is the organ where sperm is produced, and only one testis is required for this function. However, the pig may produce fewer sperm than a pig with two testes. The ability to mate a sow will depend on factors such as the pig's libido, physical condition, and the presence of any other reproductive abnormalities.

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Rubber produces latex. Latex is a milky fluid that is obtained from the bark of rubber trees. It is used to make a variety of products such as rubber gloves, tires, and other industrial items. Mango and citrus are fruit trees while sisal is a plant used to produce fiber for ropes and carpets.

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The most effective management system for commercial egg production depends on several factors such as space availability, cost, labor, and production goals. However, many commercial egg producers prefer the battery management system. This is because it allows for the intensive rearing of a large number of birds in a small space. The battery system involves housing hens in small cages, usually in tiers or levels, with automatic feeding, watering, and egg collection. This system offers ease of management, efficient use of space, and higher egg production per bird compared to other management systems. However, there are concerns about the welfare of the birds, and some countries have banned or restricted the use of battery cages.

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The digestion of plant fiber in non-ruminant herbivores takes place in the caecum and colon. Non-ruminant herbivores, such as horses and rabbits, are unable to digest plant fiber in the same way that ruminant animals, such as cows and sheep, can. Instead, they rely on a specialized digestive system that includes a large caecum and colon. The caecum and colon contain millions of beneficial bacteria that are able to break down the tough plant fiber through a process called fermentation. This process releases nutrients from the fiber, which are then absorbed by the animal's body. The process of fermentation is aided by the fact that non-ruminant herbivores have a relatively long digestive tract, which allows for more time for the bacteria to work on the plant fiber. Additionally, these animals may engage in coprophagy, or the consumption of their own feces, in order to further extract nutrients from their food. In summary, the digestion of plant fiber in non-ruminant herbivores takes place in the caecum and colon, where beneficial bacteria are able to break down the tough plant fiber through fermentation. This specialized digestive system allows these animals to extract nutrients from plant material that would otherwise be indigestible.

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(a)(i) Meaning of marketing channel [2 marks]

A marketing channel is the path or chain of intermediaries (middlemen) through which agricultural produce passes from the producer (farmer) to the final consumer.

(a)(ii) Marketing channels for cocoa [4 marks]

A typical channel for cocoa is:

Farmer (producer) → local buying agent/village assembler → licensed buying agent/commodity board → wholesaler/exporter → processor/overseas manufacturer → final consumer.

In short form: Producer → Middlemen (agents and licensed buyers) → Marketing board/exporter → Processor → Consumer.

(b) Three characteristics of land [3 marks]

• Land is a free gift of nature (it is not produced by man).
• Land is fixed in supply (its total quantity cannot be increased or decreased).
• Land is immobile (it cannot be moved from one location to another).

(c) Three agricultural extension programmes in West Africa [3 marks]

• Agricultural Development Projects (ADPs).
• Farm Settlement Schemes.
• Operation Feed the Nation (OFN) / Green Revolution programme.

(d) Four advantages of demonstration as an extension teaching method [4 marks]

• It shows farmers practically how a new practice is carried out, so learning is by seeing and doing.
• Results seen with the eyes convince farmers more easily and encourage quick adoption.
• It builds the confidence and skill of farmers in the new technique.
• It is suitable for illiterate farmers because it depends on demonstration rather than reading.

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(a)(i) What is an inventory record? [2 marks]

An inventory record is a written and up-to-date list showing all the assets and property of a farm (land, buildings, machinery, tools, livestock, stored produce, inputs, etc.), together with their quantities and money value at a particular date.

(a)(ii) Four steps involved in taking inventory [4 marks]

1. Listing (identifying and writing down) all the items and property found on the farm.
2. Counting or measuring each item to determine its quantity.
3. Valuing each item by attaching a current money value to it.
4. Recording and totalling the values to obtain the overall worth of the farm assets.

(a)(iii) Two ways inventory record is important in farm business [2 marks]

• It shows the true worth (net worth) of the farm and is used in preparing the balance sheet.
• It helps in obtaining loans and credit because it serves as evidence of the assets available as security.

(b) Four objectives of agricultural extension [4 marks]

• To teach farmers improved and modern farming practices and techniques.
• To raise the standard of living and income of rural farmers.
• To help farmers identify and solve their own farming problems.
• To pass research findings and innovations from research stations to the farmers.

(c) Extension teaching methods [4 marks]

(i) News bulletin: This is a printed sheet or short broadcast that carries up-to-date farming information, announcements and advice to many farmers at the same time. It is used to give timely reports on prices, new inputs, weather and events, spreading information quickly and cheaply over a wide area.

(ii) Agricultural shows: These are organised exhibitions where farmers, research bodies and companies display improved crops, livestock, tools and produce. They allow farmers to see new varieties, breeds and machines, compare results, exchange ideas, and are motivated (through prizes and competition) to adopt improved practices.

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(a)(i) Meaning of culling in poultry production [2 marks]

Culling is the deliberate removal (selecting out and disposing of) of undesirable, unproductive, sick, weak or old birds from a flock in order to keep only the healthy and productive stock.

(a)(ii) Three benefits derived from culling [3 marks]

• It removes unproductive birds, so feed is not wasted on non-layers and cost of production is reduced.
• It removes sick and weak birds, thereby checking the spread of diseases and parasites in the flock.
• It improves the overall quality and productivity of the flock, raising average egg or meat output.

(b) Four ways of preventing diseases in a sheep flock [4 marks]

• Vaccinate the sheep regularly against common diseases such as PPR (peste des petits ruminants).
• Provide clean feed, clean drinking water and good sanitation in the pen.
• Deworm the flock routinely and dip or spray them to control external parasites (ticks, lice).
• Isolate (quarantine) newly bought or sick animals to prevent the introduction and spread of disease.

(c) Paddocking as a way of improving rangeland [4 marks]

Paddocking is the division of a large range or pasture into smaller fenced units called paddocks so that animals can be grazed in one paddock at a time while the others rest and regrow. By rotating the animals from paddock to paddock, the grasses are not overgrazed and are given time to recover and re-establish, which maintains a good stand of nutritious forage. It allows even utilisation of the pasture, prevents selective grazing and trampling, permits the resting paddocks to be treated (reseeded, fertilised or weeded), helps to break the life cycle of internal parasites, and makes it easier to manage and control the movement of the herd. Overall, paddocking increases the carrying capacity and productivity of the rangeland.

(d) Three fishery regulations [3 marks]

• Prohibition of the use of harmful fishing methods such as chemicals, explosives (dynamite) and poisons.
• Use of nets with an approved (large) mesh size so that young/immature fish are not caught.
• Observance of a closed season and licensing of fishermen to prevent over-fishing and protect breeding stock.

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(a)(i) What is an agricultural system?

An agricultural system is a particular method or pattern of organising and carrying out farming activities (the way crops are grown and/or animals are reared) on a piece of land to achieve production goals.

(a)(ii) Five agricultural systems practised in West Africa

• Shifting cultivation.
• Bush fallowing (land rotation).
• Mixed farming (crops and livestock together).
• Mixed cropping.
• Continuous cropping / plantation (monocropping) system.

(b) Four ways NGOs contribute to agricultural production

• They provide credit, grants and farm inputs to farmers.
• They train farmers and provide extension education.
• They fund and carry out agricultural research.
• They help provide rural infrastructure and market outlets for produce.

(c) One function of each incubator component

• (i) Counter: records/keeps track of the number of days (turns) the eggs have been incubated.
• (ii) Thermostat: automatically regulates and maintains the correct temperature inside the incubator.
• (iii) Hygrometer: measures the relative humidity (moisture content) inside the incubator.
• (iv) Egg tray: holds/supports the eggs in position (and aids turning) during incubation.
• (v) Heater: supplies the heat needed to keep the eggs warm for the embryos to develop.

Antwoorddetails

(a) Four soil conservation practices to control erosion on a gentle slope

• Contour ploughing/cultivation.
• Cover cropping (and mulching).
• Strip cropping.
• Crop rotation (and afforestation/planting cover vegetation).

(b) How each practice conserves the soil

• Contour ploughing: The ridges and furrows are made across the slope (along the contour). They act as barriers that trap running water, slow it down and encourage it to soak into the soil instead of washing the topsoil away.
• Cover cropping/mulching: The cover crop or mulch shields the soil surface from the direct impact of raindrops, reduces the speed of run-off, holds the soil particles together with roots and adds organic matter that improves soil structure and water retention.
• Strip cropping: Erosion-permitting crops (row crops) are alternated in strips with close-growing, soil-protecting crops across the slope. The protective strips slow down run-off and trap soil washed from the open strips, reducing the total soil lost.
• Crop rotation: Growing different crops, including cover/leguminous crops, in sequence keeps the ground continuously covered, improves soil structure and organic matter, and reduces the exposure and loss of bare soil to erosion.

Antwoorddetails

(a) Four characteristics of clay

• It has very fine particles (less than 0.002 mm).
• It has high water-holding capacity and drains poorly (poor aeration).
• It is sticky and plastic when wet, and hard/cracks when dry.
• It is heavy to work (heavy soil) and generally high in nutrients (high cation exchange capacity).

(b) Four effects of drought on plant growth and development

• Wilting and eventual death of plants.
• Stunted growth and reduced yield.
• Shedding of leaves, flowers and fruits (premature ripening).
• Reduced germination and poor nutrient uptake (nutrients cannot dissolve without water).

(c) Two symptoms of phosphorus deficiency in crops

• Purplish/reddish colouration of the leaves and stem.
• Stunted growth with poor root development and delayed maturity.

(d) Importance of soil properties in crop production

(i) Soil reaction (pH):

• It determines the availability of plant nutrients in the soil.
• It affects the activity of soil micro-organisms (for example nitrogen-fixing bacteria).
• It influences which crops can grow well, since crops have preferred pH ranges.

(ii) Soil temperature:

• It affects the rate and speed of seed germination.
• It influences the rate of root growth and nutrient/water absorption.
• It affects the activity of soil micro-organisms and the rate of decomposition of organic matter.

Antwoorddetails

(a)(i) Definition of brooder

A brooder is a specially heated house or equipment used to provide artificial warmth and care for day-old chicks in the absence of a mother hen, until they can regulate their own body temperature.

(a)(ii) Four characteristics of a good layer

• A bright red, well developed comb and wattles.
• A large, soft and moist vent.
• Wide spacing (three to four fingers) between the pelvic bones.
• Alert and active with bleached (pale) shanks and beak from continuous laying.

(b) Four reasons for providing suitable housing for livestock

• To protect the animals from harsh weather (rain, sun, cold, wind).
• To protect them from predators and thieves.
• To make feeding, watering, management and disease control easy.
• To provide comfort and reduce stress, thereby improving growth and production.

(c) Scientific names of three fish species commonly stocked in a pond

• Oreochromis niloticus (tilapia).
• Clarias gariepinus (African catfish).
• Heterotis niloticus (also Heterobranchus species).

(d) Three qualities of a good pasture plant

• It should be highly palatable and nutritious (high protein).
• It should be fast growing and produce high yield of herbage.
• It should be persistent, drought tolerant and able to withstand repeated grazing/trampling.

Antwoorddetails

Production of cocoa (Theobroma cacao)

(a) Land preparation

The land is cleared, with some tall forest trees deliberately left or shade trees planted to provide shade for the young cocoa. The undergrowth is slashed and the debris packed, avoiding complete clearing so that the soil and young seedlings are protected. Planting holes are then dug and lined out.

(b) Climatic requirements

• High rainfall of about 1,000 mm to 2,000 mm, well distributed through the year.
• Warm temperature of about 21 to 32 degrees Celsius.
• High relative humidity and shade, sheltered from strong winds.

(c) Planting

• Cocoa is first raised in a nursery from seeds (pods), usually in polythene bags under shade, for about four to six months.
• Seedlings are hardened off and transplanted to the field at the onset of the rains.
• Planting is done at a spacing of about 3 m x 3 m (roughly 1,100 stands per hectare) under temporary/permanent shade.
• The seedlings are planted carefully into the prepared holes, watered and mulched to establish them.

(d) One disease of cocoa

Black pod disease, caused by the fungus Phytophthora palmivora. It causes black or brown spots that spread over the pods, rotting them, and can be controlled by regular harvesting, removal/burning of infected pods and spraying with a copper-based fungicide (for example Bordeaux mixture).

Antwoorddetails

(a) Four aims of crop improvement

• To develop high-yielding varieties.
• To develop varieties resistant to pests and diseases.
• To produce early-maturing varieties.
• To improve the quality of produce and develop varieties tolerant of adverse conditions (drought, poor soils).

(b) Four conditions necessary for seed germination

• Adequate water (moisture).
• Suitable/warm temperature.
• Oxygen (air).
• Viable seed (and, for some seeds, light).

(c) Importance of conducting a germination test

It is done to determine the viability (percentage germination) of the seeds, so that the farmer knows the quality of the seed and can decide the correct seed rate to plant and avoid wasting time and land on seeds that will not germinate.

(d) Three problems associated with poor quality planting materials

• Poor germination: low-viability seeds give patchy, uneven stands and gaps in the field, reducing plant population.
• Low yield: weak or unimproved materials produce sickly plants that give poor yields and low-quality produce.
• Disease and pest carry-over: infected planting materials introduce and spread pests and diseases into the field, causing further crop losses.

Antwoorddetails

(a) Six factors that limit food production in West Africa

• Inadequate finance/capital and credit for farmers.
• Use of poor tools and low level of mechanisation.
• Pests and diseases of crops and livestock.
• Unfavourable/unreliable climate (drought, erratic rainfall).
• Poor storage, processing and transport facilities leading to high losses.
• Poor/infertile soils, land tenure problems, and inadequate improved inputs (seeds, fertilizer).

(b) Solar energy as a source of farm power

Three advantages:

• It is free, renewable and inexhaustible once the equipment is installed.
• It is clean and does not pollute the environment.
• It requires little maintenance and can be used in remote areas without a power grid.

Three disadvantages:

• It is not available at night and is unreliable on cloudy/rainy days.
• The initial cost of the equipment (panels, batteries) is high.
• It produces relatively small amounts of power and requires storage (batteries) for continuous use.

(c) Four tractor-coupled implements

• Plough.
• Harrow.
• Ridger.
• Planter (also harvester/trailer).