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The Importance of Plant Science W HERE would we be without plants? Without plants, we and all other animals would not exist. We primarily depend on plants for food. We also depend on plants for fiber, shelter, medicines, and industrial products. This unit focuses on the importance of plants in our lives. Objective: þ Explain the importance of plant science. Key Terms: Ñ agronomy cereal grain fiber crops fibers field crops floriculture foliage food crop horticulture forage forestry fruit grain crops grasses herb horticulture legumes nursery/landscape nut crops oil crops olericulture ornamental horticulture plant domestication plant science pomology spice sucrose sugar crops tree farms turf vegetable vegetable, fruit, and nut crops Plant Science Plant science is the study of the structure, functions, growth, and protection of plants. Plant science can be divided into three major segments—agronomy, horticulture, and forestry. E-unit: The Importance of Plant Science Page 1 u www.MyCAERT.com Copyright © by CAERT, Inc. — Reproduction by subscription only. E040108 Agronomy is a specialized area of plant science that deals with field crops. Agronomy includes the relationship between plants and the soil. Field crops are plants grown in large fields for oil, fiber, grain, and similar products. Field crops, such as corn and wheat, are often grown for their seed, but other parts may also be used. FIGURE 1. Field of wheat. Horticulture is the production and use of plants for food, comfort, and beauty. There are two major areas of horticulture. These are ornamental and food crop production. Ornamental horticulture is growing and using plants for their beauty. Two main divisions of horticulture are floriculture and nursery/landscape. Floriculture is the production and use of plants for their flowers and foliage. Foliage is the stems and leaves of the plant. Nursery/landscape is growing and using plants to make the outdoor environment more appealing. It includes trees, shrubs, vines, flowering plants, and ground covers. Food crop horticulture is growing plants for food. This can be divided into the two areas of olericulture and pomology. Olericulture is the science of producing vegetable crops. Pomology is the science of producing fruits and nuts. Forestry is the science of growing trees and producing wood products. Tree farms are cultured forests that have been carefully planned, established, and maintained. A great deal of labor FIGURE 2. Logging at a tree farm. and management goes into assuring high-quality timber. DOMESTICATED PLANTS Very few plants that play an important role in everyday life are harvested in the wild. Most of the important plants have been domesticated. Plant domestication is removing plants from their native wild environment and growing them under controlled conditions. The important field and horticultural crops of North America can be divided into different categoE-unit: The Importance of Plant Science Page 2 u www.MyCAERT.com Copyright © by CAERT, Inc. — Reproduction by subscription only. E040108 ries. Major categories are grain crops; sugar crops; oil crops; fiber crops; vegetable, fruit, and nut crops; forage crops; ornamental crops; and forest crops. Grain Crops Grain crops include plants grown for their edible seeds, not including the horticultural crops. Cereal grain is the seed of grass-type plants grown for food and animal feed. Important grain crops include rice, corn, wheat, oats, barley, rye, and sorghum. Sugar Crops Sugar crops are used as a source of sucrose sweeteners. Sucrose is a carbohydrate that provides energy for physical activity by the body. The major sugar crops are sugar beets and sugar cane. Other sources are honey, maple syrup, and some kinds of sorghum. Oil Crops Oil crops are plants grown for FIGURE 3. Sugar cane field. the vegetable oil contained in their seed and fruit. Some of the major oil crops are soybeans, cotton, canola, and corn. Other common oil seeds are sunflower, safflower, peanut, coconut, linseed, and palm. Fiber Crops Fiber crops are crops grown for the fiber produced in their fruit, leaves, or stems. Fibers are tiny threadlike structures used in manufacturing cloth, paper, and other materials. Cotton is the major fiber crop. Others include flax, kenaf, hemp, jute, and ramie. Vegetable, Fruit, and Nut Crops Vegetable, fruit, and nut crops are grown primarily for food. There are many different types of plants that are included in this category. A vegetable is usually a herbaceous plant grown for an edible part, such as leaves, stems, seeds, and roots, which is FIGURE 4. An apple orchard. E-unit: The Importance of Plant Science Page 3 u www.MyCAERT.com Copyright © by CAERT, Inc. — Reproduction by subscription only. E040108 usually eaten as part of a meal. Examples of vegetables include lettuce, asparagus, and carrots. A fruit is a succulent reproductive body of a seed plant used chiefly in a dessert or sweet course. Common fruits are apples, raspberries, and bananas. Nut crops are a group of botanically unrelated plants that are grouped together because their fruit type is a nut, and the harvesting, post-harvest processing, nutritional value, and marketing characteristics are relatively similar. Nut crops include walnuts, macadamia nuts, and pistachio. Forage Crops Forage crops are primarily grasses and legumes. Grasses are nonwoody plants that have parallel veins in their leaves. Grass plants used for forage include Bahia grass, ryegrass, and fescue. Legumes are broadleaf plants that have the potential of fixing nitrogen from the air into the soil, such as alfalfa, clover, and soybeans. Forage is the leaves and stems of plants used for animal feed. It is most nutritious while the plants are still young and before seed maturity. These crops may be harvested by animals grazing in a pasture or cut, dried, and stored to be fed later. Ornamental Crops Ornamental crops include bedding plants, shrubs, trees, vines, turf, and other species grown for their beauty and personal appeal. Turf is comprised of plants used to present a pleasing appearance and protect the soil. Turfgrasses are low-growing, fine-leaved grasses used in lawns and to cover the ground to prevent soil erosion. Forest Crops Forest crops consist of trees planted for the purpose of harvest. Some uses include lumber, pulpwood, furniture, and paper. A few valued timber species include Douglasfir, longleaf pine, and black walnut. Specialty Crops There are many other crops grown for a variety of specific uses. Beverage crops, such as coffee, tea, and cocoa, are typically grow in tropical areas. Herbs and spices are grown in small FURTHER EXPLORATION… ONLINE CONNECTION: Agronomic Crops of the World Compared to the hundreds of thousands of plants on earth, we cultivate very few. Even so, many people know very little about the plants grown. Identify agronomic plants grown in your area, in the United States, and in the world. Then, conduct research to learn more about these crops. Seek answers to a number of questions. Where did the crops on which our lives depend originate? What makes them valuable? How are they related to other agronomic crops? Where are they grown? What is the economic importance of the crops? These are a few of the questions that can be answered through investigation using the Internet. As you conduct research, you will surely come up with more questions that interest you. Prepare a report to be given to your class. E-unit: The Importance of Plant Science Page 4 u www.MyCAERT.com Copyright © by CAERT, Inc. — Reproduction by subscription only. E040108 quantities throughout North America. These crops have little food value but are used to improve the flavor of food and make it more attractive. An herb is a non-woody plant with leaves, seeds, or other parts used as medicine or to enhance food. A spice is an aromatic plant part that is used to season food. Distinguishing between herbs and spices is difficult. Even with the best definitions, some overlap exists. Medicinal plants are those used in making human medicines. FIGURE 5. A sunflower field. Uses of Plants Plants are the base of the food chain for all living things. Plants are able to utilize inorganic elements and incorporate them into living tissues. Many organisms rely on plants for the energy to carry out life processes. The roles that plants play in the everyday life of all living things are numerous. A few of the most important uses are for food, industrial, medicinal, and oil. Food Many plants are edible. Whole plants or portions of plants, such as seeds and fruits, are used as a food source for many types of animals, including humans. The most important food plants are the grains of the grass family, particularly wheat, rice, corn, sorghum, and barley. In parts of the world where these crops do not grow well, such as countries found in the tropics, starchy root crops are grown for the same purpose. Some examples of these crops are yams, sweet potatoes, and manioc or cassava. About 88 percent of the world’s total caloric intake and about 80 percent of its protein intake comes from plant food sources. In addition to food, plants are used in the production of beverages. Some of the major beverages derived from plants are coffee, tea, and fruit juice. Industrial Uses Plants have industrial uses. There are several important products produced from plants, such as wood, fibers, oils, and rubber. Many of the fibers that are used in textile manufacturing come from cotton, flax, and hemp plants. The wood from timber production is used to make furniture, homes, and many other products. Many chemicals, such as acetic acid, methanol, and turpentine, are obtained from trees. Medicinal Uses Since early human development, plants have served medicinal purposes. The importance that plants play in the development of medicines is becoming increasingly evident. Scientists E-unit: The Importance of Plant Science Page 5 u www.MyCAERT.com Copyright © by CAERT, Inc. — Reproduction by subscription only. E040108 continue to study many different types of plants in order to understand the various chemical compounds found within them. Many people believe that the key to curing many of our most deadly diseases, such as cancer and AIDS, may lie within some yet undiscovered plant compound. Oil Many plants store oil as a food reserved in the seeds and fruits of the plant. Most of these plant oils are used in the production of food for humans, but some are used in industry. The soybean is the most significant oil plant. Others also play an important role in plant oil production, such as coconut, sunflower, peanut, cottonseed, and rapeseed. The Impact of Agricultural Plants on the Illinois and U.S. Economies Agricultural plants have a huge impact of on the Illinois and U.S. economies. Illinois Approximately 90 percent of the agricultural land in Illinois is used to produce crops. In 2005, there were about 72,500 Illinois farms collectively, covering 77 percent of the state. Illinois farmers produce about 17 percent of the nation’s soybeans and 17 percent of the nation’s corn. Illinois also produces significant amounts of pumpkins, horseradish, summer potatoes, popcorn, snap beans, winter wheat, grain sorghum, peaches, oats, cabbage, sweet corn, apples, nursery crops, bedding plants, and alfalfa hay. In 2005, cash receipts from marketing all crops totaled $6.9 billion. United States According to the USDA National Agriculture Statistics Service, there were over 434 million acres of cropland in the United States and 1,362,608 farms in 2002. The market value of crops, including nursery and greenhouse crops, totaled $95,151,954,000. About 19.2 percent of the United States is covered by cropland. Related Impact In addition to the crops, cropland, and farmers, plant production supports millions of Americans. Many people are employed in the processing, packaging, distributing, and marketing of crops. Summary: 2 Plant science is the study of the structure, functions, growth, and protection of plants. Plant science can be divided into three major segments—agronomy, horticulture, and forestry. E-unit: The Importance of Plant Science Page 6 u www.MyCAERT.com Copyright © by CAERT, Inc. — Reproduction by subscription only. E040108 Most of the important plants have been domesticated. The important field and horticultural crops of North America are grain crops; sugar crops; oil crops; fiber crops; vegetable, fruit, and nut crops; forage crops; ornamental crops; and forest crops. The roles that plants play in the everyday life of all living things are numerous. A few of the most important uses are for food, industrial, medicinal, and oil. Agricultural plants have a huge impact on the Illinois and U.S. economies. Approximately 90 percent of the agricultural land in Illinois is used to produce crops. The market value of crops in the United States totaled $95,151,954,000. About 19.2 percent of the United States is covered by cropland. Checking Your Knowledge: ´ 1. What is plant science? 2. What are the major categories of agricultural crops? 3. What are some of the uses of plants? 4. What is the importance of plants to the Illinois economy? 5. What is the importance of plants to the U.S. economy? Expanding Your Knowledge: L Research the origins of major agricultural crops. Identify where they were first domesticated and record the various uses of the crops. Web Links: : Plants http://www.blueplanetbiomes.org/plants.htm Writeups and Illustrations of Economically Important Plants http://www.botgard.ucla.edu/html/botanytextbooks/economicbotany/index.html A Gallery of Some Economically Important Plants http://facultystaff.vwc.edu/~presslar/EconomicBotany/index.htm Agricultural Career Profiles http://www.mycaert.com/career-profiles E-unit: The Importance of Plant Science Page 7 u www.MyCAERT.com Copyright © by CAERT, Inc. — Reproduction by subscription only. E040108