WAEC SSCE - Agricultural Science - 2016

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The cattle disease which is likely to be most common in the forest belt of West Africa is trypanosomiasis. Trypanosomiasis is caused by trypanosomes which are transmitted by tsetse flies found in areas of dense vegetation and high rainfall. These conditions are typical of the forest belt of West Africa. Cattle infected with trypanosomiasis often show symptoms such as anemia, weight loss, and reduced milk production. If left untreated, the disease can be fatal. Therefore, it is important for cattle farmers in the forest belt of West Africa to take measures to control the spread of trypanosomiasis, such as using insecticides to control tsetse flies and treating infected animals with appropriate drugs.

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Irrigation can be described as the application of water to the soil for the purpose of providing moisture to crops when there is insufficient natural rainfall. The water is supplied through various methods such as surface irrigation, sprinkler irrigation, and drip irrigation. The primary goal of irrigation is to ensure that crops receive adequate water supply to promote their growth and development, increase yield, and improve the quality of the final product.

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The farm animal which possesses a pair of caeca is the fowl, which refers to domesticated chickens, ducks, geese, and turkeys. Caeca are part of the digestive system and are responsible for the fermentation of ingested materials, particularly cellulose. They are located at the junction of the small and large intestines and are responsible for the absorption of water and the synthesis of amino acids and vitamins.

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The activity that is not a marketing function is "planting of crops". Marketing functions are those activities involved in the distribution of goods and services from producers to consumers. These functions include buying, selling, transporting, and storing of goods. Planting of crops is a production function which involves the actual process of growing crops. While it is an important aspect of agriculture, it is not directly related to marketing.

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Natural incubation is when hens are allowed to sit on their eggs and hatch them on their own. One of the disadvantages of this method is that the brooding hens sometimes abandon the eggs. This may happen due to a number of reasons, including disturbance by predators, weather changes, or lack of proper nutrition. When the hen abandons the eggs, they are left to cool and may no longer hatch. In contrast, with artificial incubation, the eggs are kept in a controlled environment, and there is a higher chance of all the eggs hatching successfully.

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In the carbon cycle, carbon dioxide in the air may be replenished by respiration. This is the process by which living organisms take in oxygen and release carbon dioxide as a waste product. During respiration, carbon dioxide is released back into the atmosphere, increasing the amount of carbon dioxide in the air. This process occurs in all living organisms, including plants and animals, and is a natural part of the carbon cycle.

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Maelezo ya Majibu

The most effective method of controlling viral diseases in crops is by "removing and burning affected crops." Viral diseases in crops spread rapidly and easily from infected plants to healthy ones, and there is no cure for them. The most effective method of controlling viral diseases in crops is to prevent their spread by removing and burning affected crops. By doing so, the viruses are eliminated from the environment and prevented from infecting other plants. This method is more effective than spraying with bordeaux mixture, practicing crop rotation, or planting at recommended spacing, which are used to prevent the spread of other types of diseases in crops.

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The correct answer is "biological control." Biological control is the practice of controlling pests or weeds using natural enemies such as predators, parasites, or pathogens. In this case, parasites and predators are used to control weeds, which means they are introduced into an area to feed on or attack the target weed, ultimately reducing its growth and spread. This method is considered more environmentally friendly compared to chemical control, as it does not involve the use of synthetic pesticides, and is a sustainable way to manage weeds in agriculture and natural ecosystems.

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Maelezo ya Majibu

The cut and carry system of feeding livestock involves cutting and carrying forage or feed to the animals instead of allowing them to graze freely. This system is termed "zero grazing" because the animals are not allowed to roam freely in search of food, but are kept in a confined space and fed on cut forage. The term "zero grazing" comes from the fact that the animals are kept in one place and do not graze on natural pastures.

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Maelezo ya Majibu

An example of an igneous rock is granite. Igneous rocks are formed from solidified magma or lava. Granite is a common type of intrusive igneous rock that forms from slow cooling of magma deep beneath the Earth's surface. It is composed mainly of quartz, feldspar, and mica, and is known for its characteristic texture and durability. Granite is widely used as a building material and for decorative purposes such as countertops and monuments.

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The price elasticity of demand measures the responsiveness of quantity demanded to a change in price. It is calculated as the percentage change in quantity demanded divided by the percentage change in price. In this case, the percentage change in price is 10% (0.1) and the percentage change in quantity demanded is -5% (-0.05) because the quantity demanded falls when the price rises. Therefore, the price elasticity of demand is: |-0.05 / 0.1| = 0.5 The answer is option (A) 0.5.

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Maelezo ya Majibu

The plant that is not a leguminous forage is B, Panicum maximum. Leguminous forages are plants that belong to the Leguminosae family and are known for their ability to fix atmospheric nitrogen through their symbiotic relationship with rhizobia bacteria. Option A, Centrosema Pubescens, is a leguminous forage plant. Option C, Stylosanthes gracilis, is a leguminous forage plant. Option D, Calopogonium mucunoides, is a leguminous forage plant. Option B, Panicum maximum, is a grass species and not a leguminous forage plant. It is often used as a grazing grass for livestock, but it does not have the ability to fix atmospheric nitrogen like leguminous forages do.

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Ruminants are animals that digest their food by fermenting it in a specialized stomach called the rumen. Dried grasses may not provide all the necessary nutrients that ruminants need to maintain good health and produce milk or meat. Therefore, ruminants fed on dried grasses are given feed supplements to provide deficient nutrients, such as protein, minerals, and vitamins, that are not present in sufficient quantities in dried grasses. These supplements help to ensure that the ruminants are getting all the nutrients they need to maintain good health and productivity.

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Continuous grazing is the method of allowing livestock to graze on a particular land continuously without rotation or rest periods. This can lead to soil degradation, soil erosion, and loss of soil nutrients. Grazing does not replenish lost soil nutrients; rather, it contributes to soil nutrient depletion. Therefore, grazing cannot be used to replenish lost soil nutrients. On the other hand, organic manuring, fertilizer application, and cover cropping are methods used in replenishing lost soil nutrients. Organic manuring involves the application of organic materials to the soil to improve soil fertility. Fertilizer application involves the application of essential plant nutrients to the soil to improve plant growth and development. Cover cropping involves the growing of certain crops to protect the soil from erosion, suppress weed growth, and improve soil fertility through nitrogen fixation.

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Cropping in fish farming refers to the process of harvesting fish from the fish pond or tank. It involves removing the mature fish from the water for sale or consumption. This process is usually done when the fish have reached the appropriate size and weight for market. It is an important aspect of fish farming as it allows farmers to obtain income from the fish they have raised.

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An agricultural extension officer should be able to guide and educate farmers. They are responsible for providing knowledge and skills to farmers to improve their agricultural practices and increase productivity. They also assist farmers in adopting new technologies and innovations to increase efficiency in their farming practices. Therefore, their main role is to educate and provide guidance to farmers.

Maelezo ya Majibu

Maelezo ya Majibu

Maelezo ya Majibu

Rhizobium is a type of bacteria that can live in symbiosis with leguminous plants such as beans, peas, and soybeans. The bacteria live in nodules on the roots of these plants and convert atmospheric nitrogen gas into a form of nitrogen that the plants can use, through a process called nitrogen fixation. The plants, in turn, provide the bacteria with a source of energy in the form of carbohydrates. Therefore, Rhizobium supplies nitrogen to leguminous plants by fixing atmospheric nitrogen into the soil.

Maelezo ya Majibu

An agricultural extension officer should be able to guide and educate farmers. Agricultural extension officers are professionals who work to help farmers improve their agricultural practices and increase their productivity. They provide education and advice on topics such as crop management, livestock care, soil health, pest control, and other important aspects of farming. They also help farmers access resources and services that can improve their operations, such as financing and technical assistance. By guiding and educating farmers, agricultural extension officers can help them make informed decisions that lead to better outcomes for their farms and communities.

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The suggestion that would solve transportation problems associated with agriculture is the "efficient railway system." An efficient railway system will provide a means of transporting agricultural products from the farms to the market or processing plants. It will reduce the cost of transportation, increase the speed of transportation, and ensure the timely delivery of agricultural products. The other options, such as the establishment of tractor hiring units, establishment of car hire units, and provision of extension services, may be helpful in other aspects of agriculture but do not directly address transportation problems.

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Maelezo ya Majibu

Maelezo ya Majibu

The surveying instrument used for measuring horizontal and vertical angles is called a theodolite. A theodolite is a precision instrument used in surveying and engineering to measure angles in the horizontal and vertical planes. It consists of a telescope mounted on a base with a graduated circle attached to it. The theodolite is used to measure angles between points, and is essential in establishing accurate distances and elevations in surveying and construction projects. The other options listed are not surveying instruments used for measuring angles. Gunter's chain is a measuring device used to measure land distances. An offset staff is used to measure vertical distances, and an arrow is a projectile used for hunting or target practice.

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Maelezo ya Majibu

The part labeled II in the diagram of the plough is a share. Its function is to make a horizontal cut into the soil, creating a furrow. The share is typically wedge-shaped, allowing it to easily slice through the soil as the plough is pulled forward.

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The question is asking which of the following methods is NOT used for preserving fish. The options are: drying, smoking, salting, and soaking. To answer the question, we need to identify the method that is not used for preserving fish. Drying, smoking, and salting are commonly used methods for preserving fish. Drying involves removing moisture from the fish, smoking involves treating the fish with smoke, and salting involves adding salt to the fish to draw out moisture and create an inhospitable environment for bacteria. Soaking, on the other hand, is not a method of preserving fish. Soaking is a process of immersing something in water or other liquid. While soaking can be used as a preparation method for cooking fish, it is not a method of preserving fish. Therefore, the answer to the question is soaking.

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The chemical equation Fe2O3 + 3H2O → Fe2O3•3H2O represents the process of hydration, which is a type of chemical weathering. In this process, water molecules combine with the iron oxide (Fe2O3) in the rock to form a hydrated iron oxide compound (Fe2O3•3H2O). This process can cause the rock to expand and weaken, making it more susceptible to erosion. Therefore, option (B) hydration is the correct answer.

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Forest resources can be managed by several measures, including taungya farming, selective exploitation, and preventing bush burning. However, promoting deforestation is not a way to manage forest resources. Deforestation is the permanent destruction of forests, which leads to soil erosion, loss of biodiversity, and climate change. Therefore, promoting deforestation would only worsen the problems associated with forest management.

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Quarantine regulations are established to prevent the introduction of foreign diseases into a country. This is done by restricting the importation of diseased plant and animal materials that may carry harmful pests and diseases. By enforcing quarantine regulations, countries can protect their agricultural industries and ecosystems from the rapid spread of foreign diseases, which could have devastating consequences for local farmers and the environment. In short, quarantine regulations are a proactive measure taken by governments to safeguard their national interests and the health of their citizens.

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Progeny selection is a breeding method that involves the selection of breeding stock based on the performance of their offspring. The aim of progeny selection is to identify superior breeding animals by evaluating the performance of their progeny. This method assumes that an animal's genetic potential can be predicted from the performance of its offspring. Therefore, animals with offspring that have superior traits such as higher growth rate, better meat quality, or disease resistance are selected for breeding. Progeny selection is considered an effective method for improving the genetic potential of a breeding population, as it allows for the selection of breeding stock based on actual performance rather than just potential.

Maelezo ya Majibu

An agricultural extension officer is a professional who works with farmers to provide guidance, education, and support. The main function of an agricultural extension officer is to help farmers improve their agricultural practices, increase productivity, and maximize their income. They achieve this by educating farmers about new agricultural technologies, techniques, and practices. Agricultural extension officers also help farmers access inputs such as seeds, fertilizers, and other resources required for farming. They also act as a liaison between farmers and other stakeholders such as government agencies, NGOs, and financial institutions. Therefore, an agricultural extension officer should be able to guide and educate farmers.

Maelezo ya Majibu

The process of removing excess maize seedlings from a stand is known as thinning. Thinning involves the removal of some of the seedlings from a crop stand to reduce overcrowding and competition for nutrients, light, and water. It is done to promote the healthy growth of the remaining plants and improve yields.

Maelezo ya Majibu

Risks on commercial farms could result from crop failure. Crop failure can be caused by various factors, such as extreme weather conditions, diseases, pests, and inadequate soil fertility. When crops fail, farmers may experience significant losses, including reduced income and profits, increased debt, and decreased food security. It is therefore important for farmers to implement risk management strategies, such as crop insurance, diversification of crops, and good agricultural practices, to minimize the impact of crop failure on their businesses.

Maelezo ya Majibu

The disadvantages of decaying organic matter in soils is that bacterials and fungal growth can be enhanced to an extent that it can lead to soil-borne diseases, plant death, and destruction of organic matter that can lead to loss of nutrients in the soil. This is because when organic matter is not properly decomposed, it can create an environment for harmful pathogens to thrive, which can affect the growth and health of plants.

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The most limiting factor affecting land availability for agriculture in urban settlements is population pressure. This is because urban areas have high population densities, and the demand for residential, commercial, and industrial space is high, leaving little land available for agriculture. As the population grows, the competition for land becomes more intense, making it difficult for farmers to secure land for agricultural purposes. The other options - soil type, topography, and climate - can also affect land availability for agriculture, but they are not as limiting as population pressure in urban areas.

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Maelezo ya Majibu

The botanical name of Northern gamba grass is Andropogon gayanus.

Maelezo ya Majibu

Maelezo ya Majibu

The activity that is not a marketing function is planting of crops. Planting of crops is a production function that involves preparing the land, planting the seeds, and nurturing the crops to maturity. On the other hand, buying of agricultural commodities, transporting of farm produce, and storage of farm produce are all marketing functions that involve activities aimed at getting the products to the final consumers in good condition and at the right time.

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Out of the options given, cocoa is the crop that requires shade at the early stage of its growth. Cocoa plants are usually grown under a shade of taller trees, which provide protection from direct sunlight and wind. The shade trees also help to maintain soil moisture and prevent soil erosion. Once the cocoa plants have grown and matured, the shade trees can be removed to allow more sunlight to reach the cocoa trees.

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The document given to a farmer on acquiring a piece of land from the government is called a "certificate of occupancy." This document certifies that the farmer has legal ownership and right to occupy and use the land for agricultural purposes. It is an important legal document that indicates the farmer's right to the land and serves as evidence of ownership. The certificate of occupancy also outlines the terms and conditions for the use of the land, including any restrictions or obligations that the farmer must abide by.

Maelezo ya Majibu

Mealybug is the insect that transmits the swollen shoot virus of Cocoa. The virus is transmitted by the pink hibiscus mealybug, a tiny insect that feeds on the sap of the cocoa plant. The mealybugs are attracted to the cocoa pods and leaves, and when they feed, they inject the virus into the plant. The virus then spreads throughout the plant, causing the symptoms of swollen shoot disease, which can be devastating to cocoa production. Therefore, the correct answer is "Mealybug".

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Most farm businesses fail due to poor management. This means that the farmer or farm manager is not effectively utilizing the available resources such as capital, labour, land, and technology to achieve maximum productivity and profitability. Poor management may include inadequate planning, lack of proper record-keeping, ineffective marketing strategies, failure to adapt to changing market conditions, and insufficient knowledge of the agricultural sector. All of these factors can lead to financial losses, low productivity, and ultimately, the failure of the farm business.

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The continuous removal of forest trees without replacement is known as "deforestation." Deforestation is the practice of clearing forests or trees permanently from a land area for various purposes, such as agriculture, mining, urbanization, or development. This practice results in a loss of biodiversity, soil erosion, climate change, and ecological imbalance. Deforestation has negative impacts on the environment, economy, and social well-being, and it is a major environmental issue facing the world today.

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Maelezo ya Majibu

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Maelezo ya Majibu

Pure line of crops are produced through continuous inbreeding. Inbreeding involves mating of closely related individuals for several generations, which leads to the production of homozygous offspring with uniform characteristics. Continuous inbreeding of selected individuals with desirable traits results in a pure line of crops with consistent and predictable characteristics. This process helps to maintain the genetic purity of the crop and is important in crop improvement programs.

Maelezo ya Majibu

(a) Farm surveying

Farm surveying is the process of measuring and mapping out the boundaries, dimensions, area, shape and relative position of a piece of farmland.

(b) Four disadvantages of electrical power

1. It cannot be easily stored in large quantities.
2. It is dangerous and can cause electric shock, electrocution or fire.
3. Its installation is costly.
4. Supply is often irregular and it is not available in many remote rural areas.

(c) Four reasons why farm machines should be maintained

1. To prolong their lifespan and durability.
2. To ensure efficient performance and reduce breakdowns.
3. To reduce the cost of major repairs.
4. To prevent accidents and ensure the safety of the operator.

(d) Land as used in agriculture

Land is the natural or physical resource, including the soil and all the free gifts of nature on and under the surface, that is used for agricultural production. It is a factor of production provided by nature.

(e) How the factors affect land availability for agriculture

• (i) Population pressure: A high population increases the demand for land for houses, roads and settlement, leaving less land for farming and leading to fragmentation and over-cultivation.
• (ii) Mining: Mining takes over and destroys large areas of land and degrades the soil, so that such land can no longer be used for crop or animal production.
• (iii) Topography: Rugged, hilly, steep or waterlogged land is unsuitable for farming, so only the gentle or flat land is easily available for cultivation.

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(a) Three systems of mating in livestock management

Stud (hand) mating: A proven sire is kept in a stud, and each dam that comes on heat is brought to him for a controlled, supervised service; the dam is then taken away. The farmer decides exactly which male serves which female, so parentage and records are accurate.

Pen mating: One selected male is placed in a pen together with a group of females that are on heat, and he is allowed to serve them freely within that pen. It is easier to manage than hand mating while still keeping the sire known.

Flock (pasture) mating: Both the sires and the dams are turned out together on the range or pasture and allowed to move about and mate freely at will. It needs little labour, but the exact parentage of the offspring is uncertain.

(b) Labelled digestive tract of a hen

Food passes through the alimentary canal of the hen in the following order:

beak (mouth) → oesophagus → crop → proventriculus (true stomach) → gizzard → small intestine (duodenum and ileum) → caeca → large intestine (rectum) → cloaca → vent.

The liver, gall bladder and pancreas are associated glands that pour their secretions into the small intestine to aid digestion. The diagram below shows these parts fully labelled and in their correct order.

(c) Five reasons why ornamental plants are important

1. They beautify the environment - homes, offices, gardens and roadsides - and are widely used in landscaping.
2. They are a source of income and employment through the florist and horticultural trade (sale of flowers, bouquets, wreaths and potted plants).
3. They are used to demarcate boundaries and, when planted as hedges, serve as windbreaks and shelter belts.
4. They provide shade, help purify the air and reduce noise pollution around buildings and roads.
5. They have educational, recreational and medicinal value, and some promote tourism and earn foreign exchange for the country.

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(a) Agricultural insurance

Agricultural insurance is a contract in which a farmer pays a regular sum of money called a premium to an insurance company, and in return the company agrees to compensate the farmer against losses arising from stated risks such as fire, flood, drought, pest and disease outbreak or death of animals. It spreads the risk of farming so that a single disaster does not ruin the farmer.

(b) Types of insurance policies

1. Specific enterprise insurance: covers only a particular named farm enterprise, for example a poultry unit, a fish pond or a cocoa plantation. The farmer is compensated only for losses affecting that stated enterprise.
2. Fire disaster insurance: protects the farmer against losses caused by outbreak of fire that may destroy farm buildings, stored produce, machinery or standing crops. The company pays the agreed value of the property destroyed by fire.
3. Life assurance: covers the life of the farmer or key farm worker. On the death of the assured person, or on reaching an agreed age, the insurance company pays the agreed sum to the beneficiaries or to the assured.

(c) Process of egg formation in a hen

1. The ovary releases a mature ovum (yolk) into the funnel-shaped infundibulum, where fertilisation takes place if sperm are present.
2. The yolk moves into the magnum, where the thick albumen (egg white) is added over several hours.
3. It then passes into the isthmus, where the two shell membranes are formed around the albumen.
4. In the uterus (shell gland) water and mineral salts are added and the hard, calcareous egg shell together with its shell pigment is deposited; this is the longest stage.
5. Finally the completed egg passes through the vagina and cloaca and is laid through the vent, usually blunt end first.

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(a) Five differences between subsistence and commercial agriculture

(b) Two solutions to each problem

(i) Inadequate land

1. Introduce land reform and land-use laws to make land available.
2. Discourage fragmentation by consolidating small holdings, and practise intensive farming.

(ii) Inadequate finance

1. Provide agricultural credit and loans through banks.
2. Give government subsidies and encourage cooperative societies to pool funds.

(iii) Incidence of diseases

1. Use disease-resistant crop varieties and animal breeds.
2. Carry out regular spraying and vaccination and establish quarantine.

(c) Agricultural ecology

Agricultural ecology is the study of the relationship or interaction between crops and farm animals and their environment (both the living and the non-living components).

(d) Five sources of pollution of agricultural lands and fish ponds

1. Industrial waste and effluents.
2. Oil spillage.
3. Agrochemicals (pesticides and herbicides).
4. Excess inorganic fertilizers washed into water.
5. Sewage and domestic refuse.

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(a) Staking in yam cultivation

Staking is the practice of providing stakes or poles to which the growing yam vines are tied so that they can climb and spread. This exposes the leaves fully to sunlight for efficient photosynthesis, which leads to bigger tubers and higher yield.

(b) Nursery practices in cocoa cultivation

1. Prepare a nursery site near a source of water and provide overhead shade.
2. Fill polythene bags with fertile topsoil.
3. Select viable, pre-germinated seeds and sow one seed per bag.
4. Water the seedlings regularly and keep the nursery weed-free.
5. Apply manure or fertilizer and control pests and diseases.
6. Harden off the seedlings by gradually removing the shade before transplanting after about four to six months.

(c) Five reasons for parboiling paddy rice

1. It makes milling easier and reduces breakage of the grains.
2. It hardens the grain.
3. It loosens the husk from the grain.
4. It improves the nutritional (vitamin) content of the milled rice.
5. It improves the keeping or storage quality and kills insects and micro-organisms.

(d) Taungya farming: three advantages and two disadvantages

Advantages:

1. Farmers grow food crops among the young forest trees, making full use of the land.
2. It provides food and income to the farmers.
3. It reduces the cost of establishing the forest because farmers weed and tend the tree seedlings.

Disadvantages:

1. The food crops compete with the tree seedlings for nutrients, water and light.
2. Farming operations may damage the tree seedlings and expose the soil to erosion.

Maelezo ya Majibu

None