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THE VARIETY OF PLANTS
QuizĀ by OXFORD HARMONY
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2.2 Study Guide [ 2.2 Sequence Assessment 1/21 and 1/22] Ecosystems and Ecological Relationships Invasive Species ā An invasive species is a plant, animal, or organism that is not native to a specific area and causes harm to the environment or human health. Why are they harmful? Invasive species often outcompete native species for food, water, and space. They can spread quickly because they lack natural predators in the new environment. What is their impact on the ecosystem? Invasive species can reduce biodiversity by pushing native species to extinction or by changing the habitat in which native species live. Biodiversity and Its Importance to Ecosystems Biodiversity refers to the variety of life in a specific area, including different species of plants, animals, and microorganisms, and the ecosystems they form. ā Stability: Biodiversity makes ecosystems more resilient to changes such as climate change, diseases, and natural disasters. ā Food chains and webs: A greater variety of species means more sources of food for different animals, helping maintain a balanced food web. For example, a forest with many species of plants and animals can recover from a drought more easily than a forest with fewer species. Predator-Prey Relationships In a predator-prey relationship, one organism (the predator) hunts and eats another organism (the prey). The predator benefits by getting food, while the prey loses its life.The population sizes of predators and prey are often linked. If there are more prey, the predator population may grow, but if too many predators eat the prey, the predator population will decrease. This relationship can be shown in the graph below. ā For example: Lions hunt zebras for food. When there are many zebras, lions have more food and their population can grow. However, if too many lions eat the zebras, the zebra population can decrease. Predator-prey relationships help keep animal populations balanced, preventing one species from becoming too numerous and harming the environment. Ecological Relationships There are several types of relationships between organisms in an ecosystem. These include commensalism, parasitism, and mutualism. Commensalism In commensalism, one organism benefits from the relationship while the other is neither helped nor harmed. An example would be Barnacles and Whales. Barnacles attach to the skin of whales. The barnacles get access to nutrient-rich water while the whale swims, but the whale is not affected by their presence. Parasitism In parasitism, one organism (the parasite) benefits at the expense of the other organism (the host), which is harmed. For example, fleas live on dogs and feed on their blood. The fleas benefit, but the dog may suffer from itching, infections, or even anemia. Another example are tapeworms and humans. Tapeworms live in the intestines of humans and absorb nutrients, leaving the human host malnourished. Mutualism In mutualism, both organisms benefit from the relationship. An example would be bees and flowers: Bees collect nectar from flowers to make honey, while helping the flowers by transferring pollen, which helps them reproduce.
Biodiversity refers to the variety of living species on Earth, including plants, animals, bacteria, and fungi. While Earthās biodiversity is so rich that many species have yet to be discovered, many species are being threatened with extinction due to human activities, putting the Earthās magnificent biodiversity at risk.
Make a test, with answers best on the following: Conduct an investigation to provide evidence that living things are made of cells; either one cell or many different numbers and types of cells. Supporting Content LS1.A: Structure and Function ⢠All living things are made up of cells, which is the smallest unit that can be said to be alive. An organism may consist of one single cell (unicellular) or many different numbers and types of cells (multicellular). (MS-LS-1.1) Further Explanation: Emphasis is on developing evidence that living things are made of cells, distinguishing between living and non-living things, and understanding that living things may be made of one cell or many and varied cells. In multicellular organisms, the body is a system of multiple interacting subsystems. These subsystems are groups of cells that work together to form tissues and organs that are specialized for particular body functions. (MS-LS-1.3) Further Explanation: Emphasis is on the conceptual understanding that cells form tissues and tissues form organs specialized for particular body functions. Examples could include the interaction of subsystems within a system and the normal functioning of those systems. Organisms reproduce, either sexually or asexually, and transfer their genetic information to their offspring. (MS-LS-1.4) ⢠Living things share certain characteristics. (These include response to environment, reproduction, energy use, growth and development, life cycles, made of cells, etc.) (MS-LS1.4) Further Explanation: Examples should include both biotic and abiotic items, and should be defended using accepted characteristics of life. Plants, algae (including phytoplankton), and many microorganisms use the energy from light to make sugars (food) from carbon dioxide from the atmosphere and water through the process of photosynthesis, which also releases oxygen. These sugars can be used immediately or stored for growth or later use. (MS-LS-1.5) Further Explanation: Emphasis is on tracing movement of matter and flow of energy. Supporting Content LS1.C: Organization for Matter and Energy Flow in Organisms ⢠Within individual organisms, food moves through a series of chemical reactions (cellular respiration) in which it is broken down and rearranged to form new molecules, to support growth, or to release energy. (MS-LS-1.6) Further Explanation: Emphasis is on describing that molecules are broken apart and put back together and that in this process, energy is released and on understanding that the elements in the products are the same as the elements in the reactants. Organisms, and populations of organisms, are dependent on their environmental interactions both with other living things and with nonliving factors. (MS-LS-2.1) ⢠In any ecosystem, organisms and populations with similar requirements for food, water, oxygen, or other resources may compete with each other for limited resources, access to which consequently constrains their growth and reproduction. (MS-LS-2.1) ⢠Growth of organisms and population increases are limited by access to resources. (MS-LS-2.1) Further Explanation: Emphasis is on cause and effect relationships between resources and growth of individual organisms and the numbers of organisms in ecosystems during periods of abundant and scarce resources. Similarly, predatory interactions may reduce the number of organisms or eliminate whole populations of organisms. Mutually beneficial interactions, in contrast, may become so interdependent that each organism requires the other for survival. Although the species involved in these competitive, predatory, and mutually beneficial interactions vary across ecosystems, the patterns of interactions of organisms with their environments, both living and nonliving, are shared. (MS-LS-2.2) Further Explanation: Emphasis is on predicting consistent patterns of interactions in different ecosystems in terms of the relationships among and between organisms and abiotic components of ecosystems. Examples of types of interactions could include competitive, predatory, and mutually beneficial. Food webs are models that demonstrate how matter and energy is transferred between producers, consumers, and decomposers as the three groups interact within an ecosystem. Transfers of matter into and out of the physical environment occur at every level. Decomposers recycle nutrients from dead plant or animal matter back to the soil in terrestrial environments or to the water in aquatic environments. The atoms that make up the organisms in an ecosystem are cycled repeatedly between the living and nonliving parts of the ecosystem. (MS-LS-2.3) Further Explanation: Emphasis is on describing the conservation of matter and flow of energy into and out of various ecosystems, and on defining the boundaries of the system. Ecosystems are dynamic in nature; their characteristics can vary over time. Disruptions to any physical or biological component of an ecosystem can lead to shifts in all its populations. (MSLS-2.5) Further Explanation: Emphasis is on recognizing patterns in data and making warranted inferences about changes in populations, and on evaluating empirical evidence supporting arguments about changes to ecosystems. Biodiversity describes the variety of species found in Earthās terrestrial and oceanic ecosystems. The completeness or integrity of an ecosystemās biodiversity is often used as a measure of its health. (MS-LS-2.6) Supporting Content LS4.D: Biodiversity ⢠Changes in biodiversity can influence humansā resources, such as food, energy, and medicines, as well as ecosystem services that humans rely onāfor example, water purification and recycling. (MS-LS-2.6) Supporting Content ETS1.B: Developing Possible Solutions ⢠There are systematic processes for evaluating solutions with respect to how well they meet the criteria and constraints of a problem. (MS-LS-2.6) Further Explanation: Examples of ecosystem services could include water purification, nutrient recycling, and prevention of soil erosion. Examples of design solution constraints could include scientific, economic, and social considerations. Genes are located in the chromosomes of cells, with each chromosome pair containing two variants of each of many distinct genes. Each distinct gene chiefly controls the production of specific proteins, which in turn affects the traits of the individual. Structural changes to genes (mutations) can result in changes to proteins, which can affect the structures and functions of the organism and thereby change traits. (MS-LS-3.1) Supporting Content LS3.B: Variation of Traits ⢠In addition to variations that arise from sexual reproduction, genetic information can be altered because of mutations. Though rare, mutations may result in significant changes to the structure and function of proteins. Changes can be beneficial, harmful, or neutral to the organism. (MS-LS-3.1) Further Explanation: Emphasis is on conceptual understanding that changes in genetic material may result in making different proteins. Organisms reproduce, either sexually or asexually, and transfer their genetic information to their offspring. (MS-LS-3.2) Supporting Content LS3.A: Inheritance of Traits ⢠Variations of inherited traits between parent and offspring arise from genetic differences that result from the subset of chromosomes (and therefore genes) inherited. (MS-LS-3.2) Supporting Content LS3.B: Variation of Traits ⢠In sexually reproducing organisms, each parent contributes half of the genes acquired (at random) by the offspring. Individuals have two of each chromosome and hence two alleles of each gene, one acquired from each parent. These versions may be identical or may differ from each other. (MS-LS-3.2) Further Explanation: Emphasis is on using models such as simple Punnett squares and pedigrees, diagrams, and simulations to describe the cause and effect relationship of gene transmission from parent(s) to offspring and resulting genetic variation. The collection of fossils and their placement in chronological order is known as the fossil record and documents the change of many life forms throughout the history of the Earth. Anatomical similarities and differences between various organisms living today and between living and once living organisms in the fossil record enable the classification of living things. (MS-LS-4.1, MS-LS-4.2) Further Explanation: Emphasis is on finding patterns of changes in the level of complexity of anatomical structures in organisms and the chronological order of fossil appearance in the rock layers. The collection of fossils and their placement in chronological order is known as the fossil record and documents the change of many life forms throughout the history of the Earth. Anatomical similarities and differences between various organisms living today and between living and once living organisms in the fossil record enable the classification of living things. (MS-LS-4.1, MS-LS-4.2) Further Explanation: Emphasis is on explanations of the relationships among organisms in terms of similarity or differences of the gross appearance of anatomical structures. Scientific genus and species level names indicate a degree of relationship. (MS-LS-4.3) Further Explanation: Emphasis is on inferring general patterns of relatedness among structures of different organisms by comparing diagrams, pictures, specimens, or fossils. Natural selection leads to the predominance of certain traits in a population, and the suppression of others. (MS-LS-4.4) Further Explanation: Emphasis is on using concepts of natural selection, including overproduction of offspring, passage of time, variation in a population, selection of favorable traits, and heritability of traits. In artificial selection, humans have the capacity to influence certain characteristics of organisms by selective breeding. One can choose desired parental traits determined by genes, which are then passed to offspring. (MS-LS-4.5) Further Explanation: Emphasis is on identifying and communicating information from reliable sources about the influence of humans on genetic outcomes in artificial selection (such as genetic modification, animal husbandry, gene therapy), and on the influence these technologies have on society as well as the technologies leading to these scientific discoveries. Adaptation by natural selection acting over generations is one important process by which species change over time in response to changes in environmental conditions. Traits that support successful survival and reproduction in the new environment become more common; those that do not become less common. Thus, the distribution of traits in a population changes. (MS-LS-4.6) Further Explanation: Emphasis is on using mathematical models, probability statements, and proportional reasoning to support explanations of trends in changes to populations over time. Examples could include Peppered Moth population changes before and after the industrial revolution.
Escape from Unsuitable Conditions Some species can survive unfavorable environmental conditions by escaping from them temporarily. For example, desert animals usually hide underground or in the shade during the hottest part of the day. Many desert species are active at night, when temper- atures are much lower. A longer-term strategy is to enter a state of reduced activity, called dormancy, during periods of unfavorable conditions, such as winter or drought. Another strategy is to move to a more favorable habitat, called migration. An example of migration is the seasonal movements of birds, which spend spring and summer in cooler climates and migrate to warmer climates in the fall. THE NICHE Species do not use or occupy all parts of their habitat at once. The specific role, or way of life, of a species within its environment is its niche (NICH). The niche includes the range of conditions that the species can tolerate, the resources it uses, the methods by which it obtains resources, the number of offspring it has, its time of reproduction, and all other interactions with its environment. Parts of a lionās niche are shown in Figure 18-6. Generalists are species with broad niches; they can tolerate a range of conditions and use a variety of resources. An example of a generalist is the Virginia opossum, found across much of the United States. The opossum feeds on almost anything, from eggs and dead animals to fruits and plants. In contrast, species that have narrow niches are called specialists. An example is the koala of Australia, which feeds only on the leaves of a few species of eucalyptus trees. Some species have more than one niche within a lifetime. For example, caterpillars eat the leaves of plants, but as adult butter- flies, they feed on nectar. Plants and animals are able to share the same habitats because they each have different niches. FIGURE 18-6 niche from the Old French nichier, meaning āto nestā Word Roots and Origins www.scilinks.org Topic: Niche/Habitats Keyword: HM61029 mb06se_iecs02.qxd 5/24/07 10:25 AM Page 365 366 CHAPTER 18 ENERGY TRANSFER All organisms need energy to carry out essential functions, such as growth, movement, maintenance and repair, and reproduction. In an ecosystem, energy flows from the sun to autotrophs, then to organisms that eat the autotrophs, and then to organisms that feed on other organisms. The amount of energy an ecosystem receives and the amount that is transferred from organism to organism affect the ecosystemās structure. PRODUCERS Autotrophs, which include plants and some kinds of protists and bacteria, manufacture their own food. Because autotrophs cap- ture energy and use it to make organic molecules, they are called producers. Recall that organic molecules are molecules that con- tain carbon. Most producers are photosynthetic, so they use solar energy to power the production of food. However, some autotrophic bacteria do not use sunlight as an energy source. These bacteria carry out chemosynthesis (KEE-moh-SIN-thuh-sis), in which they use energy stored in inorganic molecules to produce carbohydrates. In terres- trial ecosystems, plants are usually the major producers. In aquatic ecosystems, photosynthetic protists and bacteria are usu-
Peas ļµ Peas are one of the most important vegetables Zimbabweans can grow for export. ļµ They are legumes ļµ Legumes fix Nitrogen ļµ IMPORTANCE OF PEAS ļµ Peas have a lot of health benefits for human consumption. ļµ They can be eaten raw or added to a variety of dishes ļµ Peas have vitamins and antioxidants. ļµ They are good for heart performance. ļµ They are good for dealing with high blood pressure. ļµ They have a very high protein content VARIETIES ļµ Some of the common varieties to grow are Snowbird, Sabre, Serge, Alaska, Greenfeast and Recruit ļµ Varieties are also called cultivars FAVOURABLE CLIMATE ļµ Peas prefer cold conditions to grow well. ļµ Temperatures of 22 degrees or below (starting at 13 degrees Celsius) are the best for peas farming. ļµ The best temperature is 22 degrees Celsius. ļµ Extremely hot temperatures will lead to lack of growth or hard pods. SOIL REQUIREMENTS ļµ Soil should be fertile. ļµ The soil should have good drainage. ļµ Soil pH must be in the range of 6 to 7.5. ļµ The best soil type is sandy loam ā clay soils can also cut it ļµ The soil should be deep LAND PREPARATION ļ Land preparation includes the following ļ Dig or plough to aerate the soil and improve drainage ļ Harrow to break the clods (big lumps) ļ Make ridges to keep water within the bed ļ level the bed to ensure equal water distribution SOWING AND PLANTING ļµ Seeds must be sown about 2 to 3 centimeters into the ground ļµ The germination process takes place within at most 1 week. ļµ When sowing seeds, the in-row spacing should be 5 ā 10 centimeters whereas the inter-row spacing should be 25 centimeters. Management Practices ļµ Watering is necessary but does not overdo it ā water depending on the state of the pea plants. ļµ Generally, peas do not require lots of water. ļµ WEEDING - Weeding should be done occasionally as informed by the state of the field. ļµ MULCHING ā to conserve soil moisture ļµ PEST CONTROL ā to protect crops from damage ļµ DISEASE CONTROL ā to protect crops from damage ļµ TRELLISING ā to support indeterminate varieties PEST, DISEASE AND WEED CONTROL ļµ Aphids, beetles, leaf weevils, nematodes, and leaf miners are some of the common pests to look out for. ļµ Powdery and Downey mildew, fusarium wilt are some of the common diseases to look out for. ļµ As much as you can use chemical methods to deal with pests, diseases and weeds you can still use biological and cultural control methods. ļµ Most of the pests and diseases that affect peas can be dealt with by usingcultural methods like weed control. ļµ getting rid of affected plants and plant debris can control pest and diseases control.
A symbiosis (SIM-bie-OH-sis) is a close, long-term relationship between two organisms. Three examples of symbiotic relation- ships include: parasitism, mutualism, and commensalism. Parasitism (PAR-uh-SIET-IZ-UHM) is a relationship in which one indi- vidual is harmed while the other individual benefits. Mutualism (MYOO-choo-uhl-IZ-uhm) is a relationship in which both organisms derive some benefit. In commensalism (kuh-MEN-suhl-IZ-uhm), one organism benefits, but the other organism is neither helped nor harmed. Parasitism Parasitism is similar to predation in that one organism, called the host, is harmed and the other organism, called the parasite, benefits. However, unlike many forms of predation, parasitism usually does not result in the immediate death of the host. Generally, the parasite feeds on the host for a long time rather than kills it. Parasites such as aphids, lice, leeches, fleas, ticks, and mosquitoes that remain on the outside of their host are called ectoparasites. Parasites that live inside the hostās body are called endoparasites. Familiar endoparasites are heart- worms, disease-causing protists, and tapeworms, such as the one shown in Figure 20-5. Natural selection favors adaptations that allow a parasite to exploit its host efficiently. Parasites are usually specialized anatomically and physiologically for a par- asitic lifestyle. Parasites can have a strong negative impact on the health and reproduction of the host. Consequently, hosts have evolved a variety of defenses against parasites. Skin is an important defense that prevents most parasites from entering the body. Tears, saliva, and mucus defend openings through which parasites could pass, such as the eyes, mouth, and nose. Finally, the cells of the immune system may attack para- sites that get past these defenses. parasite from the Latin word parasitus, meaning āone who eats at the table of anotherā Word Roots and Origins Tapeworms are endoparasites that can grow to 20 m or greater in length. Tapeworms are so specialized for a parasitic lifestyle that they do not have a digestive system. They live in the hostās small intestine and absorb nutrients directly through their skin. Tapeworms reproduce by producing egg-filled chambers, which are released in their hostās feces to be unknowingly picked up by a future host. FIGURE 20-5 Copyright Ā© by Holt, Rinehart and Winston. All rights reserved. 404 CHAPTER 20 Mutualism Mutualism is a relationship in which two species derive some benefit from each other. Some mutualistic relation- ships are so close that neither species can survive without the other. An example of mutualism, shown in Figure 20-6, involves ants and some species of Acacia plants. The ants nest inside the acaciaās large thorns and receive food from the acacia. In turn, the ants protect the acacia from herbi- vores and cut back competing vegetation. Pollination is one of the most important mutualistic rela- tionships on Earth. Animals such as bees, butterflies, flies, beetles, bats, and birds that carry pollen between flowering plants are called pollinators. A flower is a lure for pollina- tors, which are attracted by the flowerās color, pattern, shape, or scent. The plant usually provides foodāin the form of nectar or pollenāfor its pollinators. As a pollinator feeds in a flower, it picks up a load of pollen, which it may then carry to other flowers of the same species. Commensalism Commensalism is an interaction in which one species benefits and the other species is not affected. Species that scavenge for leftover food items are often considered commensal species. However, a relationship that appears to be commensalism may simply be mutu- alism in which the mutual benefits are not apparent. An example of a commensal relationship is the relationship between cattle egrets and Cape buffaloes in Tanzania. The birds feed on small animals such as insects and lizards that are forced out of their hiding places by the movement of the buffaloes through the grass. Occasionally, the cattle egrets also feed on ectoparasites from the hide of the buffaloes, but the buffaloes gen- erally do not benefit from the presence of the egrets.
Classification of plants ⢠Plants can be classified as cultivated and wild plants. ⢠Both cultivated and wild plants are very useful to people, animals and the environment. 1. Cultivated plants: ⢠Cultivated plants are plants grown by people for selling. ⢠They can be grown in the field, vegetable garden, home garden and orchard. Classification of plants 2. Wild plants ļWild plants are plants that grow on their own outside the garden, orchard or field. ļThey have many uses such as: ⢠Food for people and animals ⢠Shelter ⢠Source of fuel in form of firewood. ⢠Examples include, grasses, msasa, yellow wood, mahogany, mopane Plant Nutrition ⢠The presence of plant nutrients in the soil make them grow well. ⢠The three major plant nutrients are nitrogen, phosphorus and potassium. Sources of plant nutrients ⢠The source for plant nutrients are grouped into organic and inorganic sources. Organic sources of plant nutrients ⢠These are found in nature. ⢠They are natural materials such, decayed plant and animal matter which include: ⢠Animal manure from cattle, sheep, goats, poultry and pigs. ⢠Green manure ⢠Legume crops like beans, peas and groundnuts. ⢠Humus ⢠These material sources may also be called natural fertilizers. Inorganic sources of plant nutrients ⢠These are sources of plant nutrients made by people in industries. They include: ⢠Compound fertilizers like compound A, B, C and D. ⢠These have two or more nutrients. ⢠Straight fertilizers like ammonium nitrate, single super phosphate and urea. ⢠A straight fertilizer supplies a single or more nutrient to the crop. A straight fertilizer A Compound fertilizer Sources of N,P,K ⢠Ammonium nitrate and Urea- contain nitrogen Double super Phosphate, Single super phosphate-contain phosphorus ⢠Muriate of Potash contains Potassium 2 . Compound fertilisers -have two or three of the three major plant nutrients (N.P.K). N-nitrogen P-phosphorus K-potassium Examples Compound D Wednesday 17 May 2023 Revision exercise (Plant nutrition) 1 .Name the 3 plant nutrients needed by plants. 2. What are the 2 groups of plant nutrients sources? 3. Give 3 examples of organic sources of plant nutrients. 4. What is a straight fertilizer? 5. Compound fertilizer supplies ā¦ā¦ā¦ā¦ā¦or ā¦ā¦ā¦ā¦ā¦ā¦. Nutrients. Vegetable crops ⢠A vegetable is any part of a plant that is eaten by humans as food part of a meal. ⢠Vegetables are grouped and named according to the part that is eaten. ⢠These are leaf, root, fruit, flower, bulb, tuber and legume vegetables. Leaf vegetables Types of veg Legume etable cropsvegetables Fruit vegetables Root, bulb and tuber Flower vegetables Cabbage Peas Tomato Root: carrots Cauliflower Rape Green beans Pepper Parsnip broccoli Spinach Melons Beetroot Tsunga Cucumber Bulb: onion Lettuce Squash Garlic kale Egg plant Leek chillies Tuber: Irish potato Wednesday 31 May 2023 Vegetable crops 1. What is a vegetable? 2. Which one is not a vegetable from the list below? a. Covo B. cabbage C. wheat D. tomato 3. Choose a vegetable which is not a fruit vegetable. a. tomato B. pepper C. kale D. egg plant 4. From which pair of vegetables do we eat the flower? A. cauliflower and garlic B. broccoli and cauliflower C. broccoli and rape D. cauliflower and pepper 5. Give one example of a vegetable belonging to each of the following groups. a. root b. legume c. bulb 6. Name any 5 groups of vegetable classification according to the parts eaten. Growing leaf vegetables ⢠Although there are many types of vegetables, the leaf, fruit and bulb vegetables are widely grown. ⢠Leaf vegetables form the greater part of vegetable crops. ⢠Leaf vegetables belong to a family called brassica. ⢠Brassicas include cabbages, lettuce, spinach, covo and many others. ⢠Each brassica family has got its own varieties called cultivar. ⢠They usually grow under the same climatic conditions and are affected by the same pests and diseases. ⢠The selection of a variety depends on the following : ļ¼The intended use of the vegetable, for example, salad, stew or snacks. ļ¼Days taken to mature. ļ¼Disease resistant ļ¼Season of the year Seedbed preparation ⢠Brassica vegetables are usually raised in seedbeds. ⢠The seedbeds are prepared by: ⢠Marking the position of the bed 1 meter in width by any length using a tape measure, hammer and pegs. ⢠Digging a seedbed to a depth of 25 to 30cm using a hoe. ⢠Breaking lumps of soil using a garden rake. Soil requirements ⢠Brassicas need: ⢠Well drained soils. ⢠Fertile soil for good growth ⢠Slightly acidic soils (pH 5.5-6) Climatic requirements ⢠Brassicas need cool to warm temperatures. ⢠Very low temperatures cause cabbages to flower which is called bolting. ⢠Brassicas can be grown throughout the year. Seedbed preparation ⢠Brassica seedlings are usually raised in seedbeds. ⢠A seedbed is prepared by: ļ¼Marking the position of the bed 1 metre in width by any length using a tape measure, hammer and pegs. ļ¼Digging a seedbed to depth of 25 to 30 cm using a hoe. ļ¼Breaking lumps of soil using a garden rake. ļ¼This is done in order to have a fine tilth and improve soil to seed contact. ļ¼Making ridges that a 15cm high. ļ¼Apply 3 to 5kg/m² of well decomposed manure. ļ¼ļ 60 to 100g/m² of compound fertilizer can be added into the soil. Management of vegetable crops ⢠After transplanting the seedlings, the seedlings need to be looked after. (a)Controlling weeds: all vegetables must be kept weed free. ⢠This is done either by hand pulling weeds or shallow cultivation using a hand fork. (b) Pest control: common pests that affect the brassicas are aphids and diamond black moth larva. ⢠Aphids are small green insects that suck the juice from the leaves leaving them with curls. ⢠They are controlled by spraying malathion using the instructions on the label. (c) Disease control: bacterial diseases are common in brassicas. ⢠Common diseases are black rot and soft rot, especially in cabbages. ⢠These are controlled by: ļ¼Crop rotation ļ¼Early planting ļ¼Planting resistant cultivars (d) Top dressing: brassicas are top dressed using Ammonium Nitrate at a rate of 2.5g per plant. ⢠Top dressing is usually done 3 or 4 weeks after germination. FIELD CROPS ⢠Field crops are crops that are grown on a large piece of land. ⢠Example of field crops: ļ¼ Maize ļ¼ Cotton ļ¼ Groundnuts ļ¼ Roundnuts ļ¼ Wheat ļ¼ Sunflower ļ¼ Tobacco ļ¼ Sugar cane ļ¼ Tea ļ¼ Coffee ļ¼ Soya beans ļ¼ sorghum Classification of field ⢠Field crops can be classified according to use such crops cereal, fibre, sugar and oil. 1. Cereal crops: ⢠A cereal is a grass grown for its edible seeds. ⢠They are also known as grain crops. ⢠The major cereal crops are maize, wheat, rice, barley, sorghum and millet. 2 . fiber crops : ⢠these are crops which are grown for their fiber and are used in making textiles, ropes and rugs. ⢠Important fiber crops are cotton, flax and sisal 3. Oil seed crops: ⢠These crops are grown for the purpose of extracting oil from their seed. ⢠The main oil seed crops are groundnuts, sunflower, soyabean and cotton seed. 4 . Sugar crops : ⢠Sugar crops include sugarcane,
Soils Southeast Asia, on balance, has a higher proportion of relatively fertile soils than most tropical regions, and soil erosion is less severe than elsewhere. Much of the region, however, is covered by tropical soils that generally are quite poor in nutrients. Often the profusion of plant life is more related to heat and moisture than to soil quality, even though these climatic conditions intensify both chemical weathering and the rate of bacterial action that usually improve soil fertility. Once the vegetation cover is removed, the supply of humus quickly disappears. In addition, the often heavy rainfall leaches the soils of their soluble nutrients, hastens erosion, and damages the soil texture. The leaching process in part results in laterites of reddish clay that contain hydroxides of iron and alumina. Laterite soils are common in parts of Myanmar, Thailand, and Vietnam and also occur in the islands of the Sunda Shelf, notably Borneo. The most fertile soils occur in regions of volcanic activity, where the ejecta is chemically alkaline or neutral. Such soils are found in parts of Sumatra and much of Java in Indonesia. The alluvial soils of the river valleys also are highly fertile and are intensively cultivated. Climate All of Southeast Asia falls within the warm, humid tropics, and its climate generally can be characterized as monsoonal (i.e., marked by wet and dry periods). Changing seasons are more associated with rainfall than with temperature variations. There is, however, a high degree of climatic complexity within the region. Temperatures Regional temperatures at or near sea level remain fairly constant throughout the year, although monthly averages tend to vary more with increasing latitude. Thus, with the exception of northern Vietnam, annual average temperatures are close to 80 °F (27 °C). Increasing elevation acts to decrease average temperatures, and such locations as the Cameron Highlands in peninsular Malaysia and Baguio in the Philippines have become popular tourist destinations in part because of their relatively cooler climates. Proximity to the sea also tends to moderate temperatures. Precipitation Much of Southeast Asia receives more than 60 inches (1,500 millimeters) of rainfall annually, and many areas commonly receive double and even triple that amount. The rainfall pattern is distinctly affected by two prevailing air currents: the northeast (or dry) monsoon and the southwest (or wet) monsoon. The northeast monsoon occurs roughly from November to March and brings relatively dry, cool air and little precipitation to the mainland. As the southwestward-flowing air passes over the warmer sea, it gradually warms and gathers moisture. Precipitation is especially heavy where the airstream is forced to rise over mountains or encounters a landmass. The east coast of peninsular Malaysia, the Philippines, and parts of eastern Indonesia receive the heaviest rains during this period. The southwest monsoon prevails from May to September, when the air current reverses and the dominant flow is to the northeast. The mainland receives the bulk of its rainfall during this period. Over much of the southern Malay Peninsula and insular Southeast Asia there is little or no prolonged dry season. This is especially marked in much of the equatorial region and along the east coast of the Philippines. While the dry and wet monsoons are important in explaining rainfall patterns, so too are such factors as relief, land and sea breezes, convectional overturning and cyclonic disturbances. These factors often are combined with monsoonal effects to produce highly variable rainfall patterns over relatively short distances. While many of the cyclonic disturbances produce only moderate rainfall, others mature into tropical stormsācalled cyclones in the Indian Ocean and typhoons in the Pacificāthat bring heavy rains and destruction to the areas over which they pass. The Philippines are particularly affected by these storms. Plant life Tropical forests in Southeast Asia Tropical forests in Southeast Asia The seasonal nature and pattern of Southeast Asiaās rainfall, as well as the regionās physiography, have strongly affected the development of natural vegetation. The hot, humid climate and enormous variety of habitats have given rise to an abundance and diversity of vegetative forms unlike that in any other area of the world. Much of the natural vegetation has been modified by human action, although large areas of relatively untouched land still can be found. The vegetation can be grouped into two broad categories: the tropical-evergreen forests of the equatorial lowlands and the open type of tropical-deciduous, or āmonsoon,ā forests in areas of seasonal drought. The evergreen forests are characterized by multiple stories of vegetation, consisting of a variety of trees and plants. Although a large diversity of tree species is found in these forests, members of the Dipterocarpaceae family account for roughly half of the varieties. Deciduous forests are found in eastern Indonesia and those parts of the mainland where annual rainfall does not exceed 80 inches. Just as in the equatorial forest, a wide variety of species is normally the rule. Certain species, such as teak, have become highly valued commercially. Teak is found in parts of Indonesia, Myanmar, Thailand, and Laos. In addition to these two basic types of vegetation, other regional patterns reflect topography. Especially noteworthy are coastal and highland plant communities. Mangrove belts, of which there are more than 30 varieties, occur where silt is deposited in coastal areas. Upland forests dominated by maples, oaks, and magnolias are found especially on mainland mountain slopes. Human activity has been rapidly altering the stands of virgin forest in Southeast Asia. Most deforestation results from removal for fuelwood and clearing for agriculture and grazing. Although only a relatively small portion of the total land area has been permanently cleared for cultivationāe.g., in Java (Indonesia) and western Luzon (the Philippines)āin some areas shifting cultivation has brought about the replacement of virgin forest with secondary growth. In addition, nearly all countries have commercial logging industries; notable are those in Indonesia, Malaysia, Thailand, and Myanmar. A growing problem has been illegal logging. Thus, timber harvesting has come to contribute significantly to deforestation. Programs in social forestry and reforestation have yet to halt the rapid denuding of the landscape. Animal life Southeast Asia is situated where two major divisions of the worldās fauna meet. The region itself constitutes the eastern half of what is called the Oriental, or Indian, zoogeographic region (part of the much larger realm of Megagaea). Bordering along the south and east is the Australian zoogeographic region, and the eastern portion of insular Southeast AsiaāCelebes (Sulawesi), the Moluccas, and the Lesser Sunda Islandsāconstitutes a transition zone between these two faunal regions. a classroom in Brazil More From Britannica education: Southeast Asia Southeast Asia is notable, therefore, for a considerable diversity of wildlife throughout the region. These differences are especially striking between the species of the eastern and western fringes as well as between those of the archipelagic south and the mainland north. The differences stem largely from the isolation, over varying lengths of geologic time, of species following their migration from the Asian continent. In addition, the tropical rain forests in many parts of the region, with their great diversity of vegetation, have made possible the development of complex communities of animals that fill specialized ecological niches. Especially numerous are arboreal and flying creatures. orangutans orangutansOrangutans (Pongo pygmaeus) in Sumatra, Indonesia. The distinction between the two faunal regions is best depicted by their mammal populations. In general, Australia is inhabited largely by marsupials (pouched mammals) and monotremes (egg-laying mammals), while Southeast Asia contains placental mammals and such hybrid species as the bandicoot of eastern Indonesia. Small mammals such as monkeys and shrews are the most numerous, while in many areas the larger mammals have been pushed into more remote areas and national preserves. Bears, gibbons, elephants, deer, civets, and pigs are found in both mainland and insular Southeast Asia, as are diminishing numbers of tigers. The Malayan tapir, a relative of the rhinoceros, is native to the Malay Peninsula and Sumatra, while the tarsier is found in the Philippines and parts of Indonesia. A number of rare endemic species are found in Indonesia and East (insular) Malaysia, including the Sumatran and Javan rhinoceros, the orangutan, the anoa (a dwarf buffalo), the babirusa (a wild swine), and the palm civet. As the pace of development accelerates and populations continue to expand in Southeast Asia, concern has increased regarding the impact of human activity on the regionās environment. A significant portion of Southeast Asia, however, has not changed greatly and remains an unaltered home to wildlife. The nations of the region, with only few exceptions, have become aware of the need to maintain forest cover not only to prevent soil erosion but to preserve the diversity of flora and fauna. Indonesia, for example, has created an extensive system of national parks and preserves for this purpose. Even so, such species as the Javan rhinoceros face extinction, with only a handful of the animals remaining in western Java