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Chapter 2 origin of agriculture and the domestication of plants.

ABSTRACT

A variety of theories are involved in the origin of agriculture and the domestication of plants. This chapter begins with a brief description of five key theories on the origin of agriculture, including agriculture as a divine gift, agriculture as a discovery, agriculture as a result of stress, agriculture as an extension of gathering, and agriculture as a result of no specific model. The basis for selecting edible plants and the resulting major food crops used today is also explained.

A chronological history of agriculture picks up with a discussion of the Egyptian, Greek, and Roman civilizations, which is followed, after the fall of the Roman Empire, by the medieval era. History continues with the Renaissance (a time of rebirth in the arts and sciences), which is followed by the Age of Discovery and the New World. Into modern times, the beginnings of experimental science are covered, along with the beginnings of agricultural research in the United States.

A brief description of the origin of cultivated species shows that earlier scientists, namely de Candolle and Vavilov, believed that there were eight centers of plant origin. More recently, Harlan, an agronomist, states that probably three centers contributed to the propagation of agriculture around the world. The chapter concludes with a discussion of the 13 primary regions of the world where major food crops were domesticated, along with examples of the crops that characterized each of these regions.

Objectives

After reading this chapter, you should be able to

* discuss several theories on the origin of agriculture and why it represents one of the most significant achievements by the human civilization.

* provide background information on the selection of edible plants used today.

* discuss the major contributions that the Egyptian, Greek, and Roman civilizations have made to agriculture.

* provide background information on medieval horticulture and agriculture.

* discuss the impact of the Age of Discovery and the New World on agriculture today.

* provide background information on the beginnings of experimental research throughout the world and agricultural research in the United States.

* discuss some theories of the origins of cultivated plants and the 13 major regions of the world where major food crops were domesticated.

Key Terms

agriculture

agricultural adjustment act

agricultural experiment station

Agricultural Marketing Act

agronomy

Charles Darwin

Dark Ages

Dioscorides

Egyptian

forestry

Greek

Gregor Mendel

Hatch Act

horticulture

Joseph Priestley

Linnaeus

Manorial System

Marcello Malpighi

Marco Polo

Morrill Land Grant College Act

Nehemiah Grew

Pliny the Elder

Renaissance

Robert Hooke

Roman Empire

Rudolph Camerarius

Stephen Hales

Theophrastus

U.S. Department of Agriculture

INTRODUCTION

Although many theories exist on the origin of agriculture (the production of plants and animals to meet basic human needs), one fact remains clear: agriculture provided the human civilization with an available and dependable food supply (Figure 2-1). The advent of agriculture led to a new class of specialists--scientists, artists, engineers, and others--which in turn led to discoveries that increased the quality of human life. Interestingly, in the past, humans used thousands of plant species as food sources, thereby enjoying a highly varied diet. Only a small number of these species were ever domesticated, and with fast food prevalent in many diets, even fewer plant species are now being grown on a large scale.

The major accomplishments of Egyptian agriculture were the development of irrigation systems, drainage methodology, and land preparation methods using the hoe and plow. The Greeks contributed to agriculture indirectly through their great contributions to the study of botany. The Roman Empire soon followed the Greek civilization and lasted for about 1,000 years. Even though the Romans added little new information to agriculture, they made dramatic improvements to existing technology, such as grafting and budding, legume rotation, fertility analysis, and postharvest storage of fruits and vegetables. The Romans also described a prototype greenhouse, which was used to force vegetables. Medieval times were a stagnation period for the arts and sciences in the West. However, during this period, horticulture and other cultural activities were flourishing in the East (India, China, Japan, and others). Following the medieval times, the Renaissance blossomed and is described as the rebirth of the arts and sciences. Works by Leonardo da Vinci, Michelangelo, and others were key to this period. Experimental science began with da Vinci, Galileo, and Newton, and because of their innovative findings, there was a dramatic rise in botanical research.

Agricultural research in the United States began in 1862 when Congress passed bills constituting the U.S. Morrill Land Grant College Act; also that same year, the United States Department of Agriculture was created. Since that time, numerous studies in agricultural research have been conducted in the United States.

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Clearly, centers of plant origin from which agriculture was propagated occurred around the world; however, the actual number of centers is still debated. Many believe there were 13 major regions of the world where plants were domesticated: North America, Meso-America, Highland South America, Lowland South America, Europe, Africa, Near East, Central Asia, India, Southeast Asia, China, South Pacific, and Australia (Figure 2-2). Plants are thought to have been domesticated toward the end of the ice age or 11,000 to 15,000 years ago, and this occurred over a wide geographical range. Considering that some believe humans have been on Earth for approximately 4 million years, the domestication of plants is relatively new. However, the question of where plants were domesticated is much more complex than it appears.

THEORIES ON THE ORIGIN OF AGRICULTURE

In Crops and Man (Harlan, 1992), the many theories on the origin of agriculture theories are presented in detail; however, for the purpose of this introductory text, following is a brief summary of the five major theories.

* Agriculture as a divine gift. Although there are many descriptions on the origin of agriculture based on classical histories from a variety of civilizations, the same general theme is that agriculture was given as a divine gift.

* Agriculture as a discovery. The origin of agriculture based on invention or discovery has received a great deal of attention. Although there are many theories on how agriculture was discovered, the theories proposed by Sauer (1952) and Anderson (1954) are the most widely accepted.

* Agriculture as a result of stress. A considerable amount of support exists for the theory proposed by Cohen (1977), which suggests the increased stress caused by an increase in population and depleted resources led to the adoption of agriculture as a means of procuring food.

* Agriculture as an extension of gathering. In primitive societies based on hunting/gathering, humans had the knowledge to develop agriculture but elected not to. Basically, hunter/gatherers did not farm because food in the wild was plentiful. A quote taken from Berndt and Berndt (1970) by the Aborigines sums this point up nicely:
   You people go to all that trouble, working and planting seeds, but
   we don't have to do that. All these things are there for us; the
   Ancestral Beings left them for us. In the end, you depend on the
   sun and the rain just the same as we do, but the difference is that
   we just have to go and collect the food when it is ripe. We don't
   have all this other trouble.


* Agriculture as a result of no specific model. All existing models proposed thus far have been refuted in one way or another. The no-specific-model concept allows for a wide array of possibilities in which agriculture was developed. Basically, this theory recognizes that human civilization is very different in all parts of the world, and no single model can explain the origin of agriculture (Harlan, 1992).

* Agriculture (together with fire) is one of the greatest discoveries made by human civilization. In primitive societies, each individual had to be involved with procuring food for a particular group to survive. Therefore, the major limiting factor in primitive societies was the availability and dependability of a food supply. With the discovery of agriculture, this limiting factor was minimized. A surplus supply of food released people who would normally be occupied with food production to contribute to society in other ways, leading to new classes of specialists--such as scientists, artists, engineers, priests, and others--thereby contributing to an increase in the standard of living for a society. Table 2-1 outlines human progress in the fields of agriculture and horticulture over a broad period of time.

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BACKGROUND ON THE SELECTION OF EDIBLE PLANTS USED TODAY

In the past, humans used thousands of plant species as a food source; however, only a small number of these species were ever domesticated. In the early stages of agriculture, farmers unknowingly selected species that grew easily, were good producers, and required very little input. As time passed, farmers sold only the most profitable crops. In recent years, with the development of large supermarkets and fast food, the number of crops produced has decreased even further. Of the 30 major food crops cultivated today, the top 4 crops produce more annual tonnage than the remaining 26 on the list (Harlan, 1976) (Table 2-2).

This is a dangerous trend because as our society moves faster and faster, the limited number of crops currently used puts us in the position that if any one of the crops that we depend on fails, millions of people could go hungry or starve to death. For example, the potato famine, which occurred in Ireland in 1845 and 1846, claimed the lives of more than 1 million people. The majority of the population of Ireland was almost entirely dependent on the potato for its existence less than 50 years after its introduction, which allowed the failure of the potato crop to cause a national disaster. In fact, prior to the 1845 famine, the potato crop had failed in several areas, causing considerable hardship. In 1845 and 1846, crop failure was nationwide. The late blight disease, Phytophora infestans, which came from America, caused the destruction of vines and decay of the

tubers before or shortly after harvest. The disease infected potato crops in other parts of Europe at the time, but those countries (unlike parts of Ireland) were not solely dependent upon the potato.

HISTORY OF AGRICULTURE

Before agriculture, people survived by hunting and gathering. Life flourished when herds and plants were plentiful but people suffered when the food sources diminished. This led to the eventual domestication of animals and cultivation of plants. The gradual transition from a hunter/gatherer society to an agricultural society predates the invention of writing and the details are unknown.

Egyptian Civilization

The beginnings of agriculture can be traced to where the Indus, Tigris, Euphrates, or Nile rivers were located (Figure 2-3). Some of the major accomplishments of Egyptian agriculture were the development of drainage methodology (removal of excess water), irrigation systems (adding an artificial supply of water) through the use of hydraulic engineering, and land preparation by refining the hoe and perfecting the plow. The Egyptians also developed a variety of technologies associated with the culinary arts, such as ceramics, the process of baking, wine making, and food storage (for example, pickling and drying).

Because of their ability to provide water artificially through irrigation and remove it via drainage systems, the Egyptians were the first to establish exotic gardens, which were carefully planned and planted for both ornamental and utilitarian purposes. The first records date back to about 2200 B.C. to a walled garden of an official in Pharaoh Amenhotep's government. The plan for this garden was symmetrical, and shade trees surrounded the pool. All the Egyptian plantings were formal, orderly, small, and required irrigation. Typical elements found in Egyptian gardens were pools for fish; trees bearing figs, pomegranates, and dates; grapevine-covered trellises; and beds of flowers, including roses, jasmine, and myrtle (Figure 2-4). The Egyptian gardens were generally for the pharaohs and government officials, or they were sites for religious or sacred services. Egyptians developed gardens to provide an artificial oasis for privacy and a cool, leafy, shady place, for refreshment from the hot desert sun. Some suggest that the Egyptian gardens and their design were associated with the Formalism School of Landscape Design. The ancient cultures of Mesopotamia, Babylonia, and Asyria, which were located east of Egypt, added to Egyptian technology by establishing innovations such as irrigated terraces, gardens, and parks. These cultures established irrigation canals lined with brick and asphaltsealed joints to maintain more than 10,000 square miles under cultivation, which were responsible for feeding more than 15 million people.

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Greek Civilization

The Greeks were involved in agriculture in only a minor way; however, they did dedicate much attention to the study of botany and were concerned about the nature of things. When we think of Greek cultures, the names of the great philosophers Plato and Aristotle come to mind because they greatly influenced modern political and education structures. Theophrastus, Aristotle's student, is considered the most significant horticulturist. The botanical writings of Aristotle have been lost; however, the writings of Theophrastus remain intact and cover a wide range of topics, including taxonomy, plant physiology, and natural history. One of his books, History of Plants and Causes of Plants, includes topics such as plant classification, propagation, forestry, horticulture, pharmacology, viticulture, plant pests, and flavors from plants. Theophrastus has been referred to as the father of botany. The excellence of his work exemplifies the contribution the Greeks made to the science and contrasts with the period of scientific stagnation during the Middle Ages. Some speculate that the fall of the Greek Empire was not only due to war but also to a decrease in resources. Although the culture was rich in scientific thinking, the Greek mind did not show much interest in the day-to-day problems of agriculture, which can be boring but extremely important. A variety of factors, such as shallow soil and poor conservation practices, led to the decline of the Greek agricultural base. These reasons, coupled with the 27-year Peloponnesian wars, led to the fall of the Greek Empire. Although the Greek culture added only incidentally to practical agriculture, their curiosity and analytical nature had a profound effect on the future of technological advances.

Roman Civilization

The Roman Empire (Figure 2-5) soon followed the Greek civilization and then lasted for about 1,000 years. The Roman Empire was a conglomeration of a wide range of people from different lands. The Romans were fascinated with practical agriculture, and it was an integral part of their economy. Even though the Romans produced little information in the way of new discoveries, they did make great improvements. They copied and borrowed anything they thought was good from the peoples they conquered. Roman agricultural writings included information detailing grafting and budding, using many kinds of cultivated varieties of fruits and vegetables, legume rotation, fertility analysis, and methods for placing fruits in cold storage. They described a prototype greenhouse, which was used to force vegetables. A major book describing Roman agriculture, Historia Naturalis, was written by Pliny the Elder.

The Romans are thought to have first developed ornamental horticulture to a high level. Their sophisticated ornamental gardens were extensions of their houses and contained pools, statues, walkways, and vine-covered trellises. The prosperous Roman had a little piece of land with a house in the country. The estate typically included fruit orchards where apples, pears, figs, olives, pomegranates, and others were grown. In addition, flower gardens contained lilies, roses, violets, pansies, poppies, irises, marigolds, snapdragons, and asters. The wealthy Roman had an estate with a mansion surrounded by frescoed walls containing statues, fountains, trellises, flower boxes, shaded walks, terraces, topiaries (bush sculptures), and, in many cases, even heated swimming pools. The numerous courtyards and symmetric plantings were characteristics typical of Roman cities.

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Medieval Horticulture and Agriculture

The time between the fall of the Roman Empire and the Renaissance was the medieval period also known as the Dark Ages. During this period, the development of horticulture was static, as was the case with the other arts and sciences. The Dark Ages were restricted to the West, because in the East (India, China, Japan, and others), horticultural and other cultural activities were flourishing. During this period, monasteries became an important way of saving the horticultural and agricultural skills that were perfected by the Romans. Within the monasteries, there were fields of grains, vegetables, and medicinal plants collections together with orchards, located nearby (Figure 2-6). The monks were experts with herbs; they saved many unique plants that would later become very important in the Renaissance.

The Manorial System, which was derived from the manor, was an important component of the social structure in the Middle Ages. This system divided plant cultivation practices into the three areas still used today. The first was horticulture, an important component of the gardens close to the manor house, which were enclosed to protect fruits, vegetables, and herbs. The second was agronomy, which involved the cultivation of grains and forages in open fields farther away from the manor house. The third was forestry, which dealt with the wild lands containing game and forests not maintained to any extent.

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Western Europe emerged from the Dark Ages as a result of a series of changes in the political and social structures. The Crusades had a profound influence on horticultural developments because they established routine contact with the ideas and concepts of the East. Merchants such as the famous Italian family, Polo, formed an important link between the Mediterranean coasts and the China Sea by opening trade routes and introducing many goods--including plants--to Western Europe. These were important factors in the cultural enlightenment of Medieval Europe. Marco Polo is one of the more well-known Polos; his great contribution was the descriptions of the East in his book Il Milione, known in English as the Travels of Marco Polo. He provided services to the Great Khan as his administrator to great cities, busy ports, and remote provinces. As part of his services to the Khan, he had to provide detailed written reports on his travels. In addition to his geographical knowledge, Marco Polo reported that the Great Khan had trees planted to provide shade in the summer and to mark the route in winter when the ground was covered with snow.

When meat became an important part of the medieval diet, gardens were used to grow plants as a source of spices and condiments. In the section "The Apple" in the book Maison Rustique by Estienne and Liebault (1554), the authors discuss practices of fertilizing, grafting, pruning, breeding, dwarfing, transplanting, controlling insects, girdling to promote flowering, harvesting, processing, and using plants for culinary and medicinal purposes. During medieval times, herbs and herbalists were plentiful; there was little distinction between medicine and botany because plants were used in an attempt to cure all ills. The greatest authority of medicinal plants up to the Renaissance was the Greek physician Dioscorides, who wrote the authoritative book De Materia Medica.

The Renaissance

The Renaissance has been described as the rebirth of the arts and sciences and is the period in European civilization that immediately followed the Middle Ages. During this period, new continents were discovered and explored, the Copernican was substituted for the Ptolemaic system of astronomy, the feudal system declined, and commerce grew. Numerous items were invented during this period, including paper, printing, the mariner's compass, and gunpowder. The arts were reborn because of painters such as Leonardo da Vinci, Michelangelo, and others.

The Age of Discovery and the New World

During this period, the trading of spices and other horticultural products played a major role in the development of Western Europe and the settlement of the New World. Cinnamon, cardamon, ginger, pepper, and tumeric, plus frankincense, myrrh, and other fragrant resins and gums became very popular in Europe. Although the Arabian traders tried to withhold the true sources of their spices, the Europeans nevertheless discovered their origin. The Europeans built ships and went abroad to the spice-producing countries; these travels became known as the voyages of discovery now found in history books. Prince Henry the Navigator, Christopher Columbus, and John Cabot were among those who searched for spices in distant lands. For these mariners, the journeys were true adventure, but they were also filled with hard times. For example, Magellan left Spain with five vessels under his command, but only one, the Victoria, returned to Spain successfully bringing cloves. However, for European commercial interests, these journeys were highly rewarding because they broke the monopoly held by others in the spice trade and created a wide range of merchandise that was traded between Europe and the Far East, thereby opening up a New World.

The New World had numerous horticultural contributions, including many new vegetables such as maize, potato, tomato, sweet potato, squash, pumpkin, peanut, kidney bean, and lima bean. The New World also contributed fruits and nuts, such as cranberry, avocado, Brazil nut, cashew, black walnut, pecan, and pineapple, as well as other important crops, such as chocolate, vanilla, wild rice, chili, quinine, cocaine, and tobacco. One of the major results of this period was the discovery of America. As time went on, trade routes expanded, which led to further horticultural advances. The exchange between the Old and New World led to the great horticultural industry known today. Two examples of exchanges between the Old and New World include early American gardens reflecting the European origin of the settlers (English influence was predominant, as exemplified by Williamsburg) and horticultural explorers introducing plants from South America, Africa, and the Orient.

BEGINNINGS OF EXPERIMENTAL SCIENCE

Many suggest that the beginnings of experimental science started with the work of da Vinci, Galileo, and Newton in astronomy and the physical sciences. Their innovative findings caused a resurgence in botanical research. Some of the early botanical studies included the following:

* Marcello Malpighi (1628-1694) and Nehemiah Grew (1641-1712) initiated basic studies in plant anatomy and morphology. Grew wrote The Anatomy of Plants Begun and Malpighi wrote Anatome Plantarum Idea. Their independent studies were the first important descriptions and statements on the internal structure of plants (plant anatomy). The studies of Malpighi and Grew were so detailed and complete that little new information to the field was added for more than 100 years. In their books, they described the structure of buds, the organization of wood, the characteristics of flowers and their separate parts, the generation of the seed and embryo, and a variety of other topics that had never been explored before.

* Robert Hooke (1635-1703) found that living things were made of cells, which led to the future study of cytology.

* Rudolph Camerarius (1665-1721) demonstrated sexuality in plants, thereby providing the start of genetics.

* Linnaeus (1707-1778) developed a simple yet elegant system for the classification of plants called binomial nomenclature, which is still used today.

* Stephen Hales (1677-1761) published the research article "Vegetable Staticks," which was the first significant publication in plant physiology. In this article, he explained some aspects of water uptake by roots, movement of liquid through plants, and evaporation of water from the leaves. His work also advanced the prospect that air provides food for plants and suggested that light was involved. He was the first scientist to use equipment and methods from the physical sciences to study plants.

* Joseph Priestley (1733-1804) showed that burning a candle in a closed container changes the quality of the atmosphere, which results in the flame going out. He also showed that animals placed in that environment would quickly die. However, when a living sprig of mint was placed in the closed container, the candle would burn again and the animal would live in the presence of the burning candle. Today we know that a growing plant takes in carbon dioxide and releases oxygen. Interestingly, upon hearing of this work, Benjamin Franklin sent a letter to Priestly. In this letter he stated, "I hope your findings on the rehabilitation of air by plants will give some check on the rage of destroying trees that grow near houses, which has accompanied our late improvements in gardening from an opinion of their being unwholesome."

* Charles Darwin (1809-1882), although better known for his book on the Origin of Species, also wrote the Power of Movement in Plants, in which he described plants' movement in response to light (phototropism) and gravity (gravitropism). This work laid the foundation for plant hormone research.

* Gregor Mendel (1822-1884) was the founder of modern genetics. In 1866, Mendel published a paper representing eight years of his research on inheritance. The original paper was published in German, but the English translation is available.

BEGINNINGS OF AGRICULTURAL RESEARCH IN THE UNITED STATES

In 1862, Congress passed bills constituting the U.S. Morrill Land Grant College Act, which was signed into law by President Abraham Lincoln. That same year, the U.S. Department of Agriculture was created. These events paved the way for the first state agricultural experiment stations located in California and Connecticut in 1875. In 1887, the Hatch Act was established, which provided yearly support to agricultural experiment stations in each state. Within 10 years, experiment stations across the United States were actively engaged in basic research with the ultimate goal of making agriculture more efficient. More than 13 million acres of federal land was given to states to support the establishment of colleges for the agricultural and mechanical arts. By 1900, there were 60 agricultural experiment stations, and this system became the basis for the U.S. Agricultural Extension service. In 1889, the U.S. Department of Agriculture was elevated to cabinet status, and the newly appointed Secretary of Agriculture had 488 employees and a $1.1 million annual budget. By 1912, the U.S. Department of Agriculture had 13,858 employees and an annual budget of $20.4 million. The overproduction or surplus of goods became a major problem during the Depression of the 1930s. To correct this problem, the Congress passed the Agricultural Adjustment Act in 1938. This act was directed at the expansion of utilization research and was accomplished by creating four regional laboratories as part of what is now called the U.S. Agricultural Research Service. Each of these laboratories had specialties in crops grown in a particular region; for example, cotton research was done in the South. In the western United States, wheat, fruits, vegetables, and alfalfa were studied. Animal products, milk, and tobacco were studied in the eastern part of the country, and grain crops, soybeans, and other oil seeds were studied in the northern United States. In 1946, the Agricultural Marketing Act was passed in order to correct the imbalance between production and postproduction research. In addition, this act put in place the mechanism for contracting with private research facilities, thereby enabling the government to use the expertise of private-sector scientists. The research addressed problems in targeted areas to obtain quick solutions to problems of national importance. As a result of World War II, regional laboratories quickly redirected their research to respond to the national crisis. USDA scientists discovered methods to produce bulk supplies of penicillin, thereby making this drug available on a wide scale. Other examples of targeting research include establishing ways to produce synthetic rubber, replacements for chemical cellulose, and dehydrated foods, as well as methods for extracting starch from wheat used as a supplement to corn for feeding livestock.

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Following World War II, research again focused on dealing with crops in surplus. The development of frozen food technology enabled consumers to have fruits and vegetables year round and to avoid dramatic seasonal changes in prices (Figure 2-7). The ability to concentrate orange juice was an amazing achievement, providing fresh juice all year long. Other accomplishments included instant potato flakes and the development of cotton-blend fabrics that were wrinkle resistant (this led to the resurgence in the use of cotton).

More recently USDA researchers have focused on a number of other areas, such as:

* organic substitutes for petroleum.

* replacing petrochemicals used to manufacture plastics with biodegradable cornstarch derivatives.

* replacing petroleum-based ink products with soy ink, which is made from soybeans.

* replacing gasoline with ethanol or other fuels, which can be made from renewable resources, thereby enabling the United States to cut dependency on foreign sources.

* looking for new and innovative ways to biologically control pests.

* using biotechnology to make foods low in cholesterol and high in vitamins and nutrients.

* searching for new crops worldwide or genetically engineering plants for use as renewable resources for a variety of purposes. Some possibilities include producing a substitute for wood pulp in making paper, producing plants that make oral vaccines to be used for a variety of diseases, and producing plants that produce pharmaceuticals.

From the start of the first U.S. experiment station to the present and even into the future, agricultural research is and will continue to be an important part of our daily lives.

THEORIES OF THE ORIGINS OF CULTIVATED PLANTS

The nineteenth-century French botanist, de Candolle, the twentieth-century Russian agronomist and geneticist, Vavilov, and more recently the American agronomist, Harlan, have published extensively on the geography of plant domestication and crop origins. Both de Candolle and Vavilov concluded that eight centers of plant origin existed (de Candolle, 1959; Vavilov, 1926). Although Harlan (1992) states that just three centers have mostly contributed to the propagation of agriculture around the world, many books have been written on the geographical areas of early agriculture. For more details in this area refer to Harlan (1992).

The current view states that plants were cultivated at approximately the same time over a wide geographical range. The major food crops were domesticated at roughly the same time in the 13 major regions of the world. Today these crops are the staples of our lives. Recall that the 13 major regions where plants were domesticated are North America, Meso-America, Highland South America, Lowland South America, Europe, Africa, Near East, Central Asia, India, Southeast Asia, China, South Pacific, and Australia. The time frame during which the domestication of plants occurred was during the Pleistocene epoch of the Cenozoic era, which was toward the end of the Ice Age or about 11,000 to 15,000 years ago, when early humans began wandering the Earth. Prior to this time, some theories project that tool-using hunter/gatherers had been on Earth for about 4 million years. According to these theories, the domestication of plants began only about 400 generations ago.

Determining where plants were domesticated is complex because some of the plants originally domesticated are much different from the plants used today; in many cases, these plants are the same in name only. For example, three kinds of wheat were originally domesticated, none of which are commercially used today; in fact, these plants are hardly grown at all. The wheats originally domesticated were diploids and tetraploids, known as glume wheats. Today the major wheat species used are hexaploids, known generally as bread wheat, which have very different characteristics than those originally domesticated (Harlan, 1976).

SUMMARY

After reading this chapter, it should be clear that the development of agriculture is one of the most important discoveries affecting the human race, even though its origin is still open for discussion. It was because of agriculture that many other discoveries were made. The Egyptian and Roman civilizations contributed directly to the development and betterment of agriculture, whereas the Greeks contributed in a less direct way. The Egyptians' most significant contribution to agriculture was the development of irrigation systems, drainage methodology, and land-preparation methods using the hoe and plow. The Romans took existing technology and made it better, thereby adding to agriculture in a variety of ways, including:

* grafting and budding.

* legume rotation.

* fertility analysis.

* postharvest storage of fruits and vegetables.

* prototype greenhouse used to force vegetables.

Although the Greeks did not have a direct impact on agriculture, they did provide us with great thinkers such as Plato, Aristotle, and Aristotle's student, Theophrastus. Following the Egyptian, Greek, and Roman civilizations, there was a period of stagnation during medieval times known also as the Middle Ages and the Dark Ages. During this time, horticulture made little strides in the West; however, in the East (India, China, and Japan), major discoveries were being made. After the Dark Ages, the Renaissance occurred and, men such as da Vinci, Galileo, and Newton were key to the surge in botanical research. Key names to be remembered for their contributions to the botanical sciences are Marcello Malpighi, Nehemiah Grew, Robert Hooke, Rudolph Camerarius, Linneaus, Stephen Hales, Joseph Priestly, Charles Darwin, and Gregor Mendel. The following key dates in U.S. agriculture should also be noted.

* In 1862, the U.S. Morrill Land Grant College Act was passed, which led to the establishment of land grant colleges throughout the United States. At the same time, the U.S. Department of Agriculture was formed.

* In 1875, the first state agricultural experiment stations located in California and Connecticut were established.

* In 1887, the Hatch Act was established, which provided yearly support to agricultural experiment stations in each state.

There were 13 major regions of the world where plants were domesticated. You have read that plants were domesticated toward the end of the Ice Age, or 11,000 to 15,000 years ago, and this occurred over a wide geographical range at basically the same time. Considering that theories project man to have been on Earth for approximately 4 million years, the domestication of plants is relatively new. When considering where plants were domesticated, it is important to understand that the answer is much more complex than it appears. (For more details in this area, a good starting point is Harlan's works published in 1976 and 1992.)

Review Questions for Chapter 2

Short Answer

1. What is the definition of agriculture?

2. List five theories on the origin of agriculture and provide a brief explanation of each.

3. What was the major limiting factor in primitive societies?

4. What was the immediate reward of agriculture, which provided an available and dependable supply of food?

5. What are the top four major food crops produced today?

6. Provide examples of food crops domesticated in each of the 13 major regions of the world.

7. What was the time frame during which the domestication of plants occurred?

Define

Define the following terms:

Hatch Act

Agricultural Adjustment Act

Agricultural Marketing Act

True or False

1. The time frame during which domestication of plants occurred was toward the end of the Ice Age.

2. The current view holds that plants were domesticated at different times over a wide geographical range.

3. One of the major accomplishments of the Egyptian civilization was the development of irrigation systems through the use of hydraulic engineering.

4. The Greek civilization was only involved in practical agriculture in a minor way.

5. Although the Greeks were great scientific thinkers, they did not show much interest in the day-to-day problems of agriculture.

6. The Romans produced very little new discoveries, but they did make great improvements on existing technology.

Fill in the Blanks

1. There are--major regions of the world where major food crops were domesticated.

2. Agriculture is the production of--and--to meet basic human needs.

3. The--was the period of time which immediately followed the Middle Ages.
Matching

1. Hatch Act (1887)          A. Passed to correct the imbalance
                                between production and postproduction
                                research

2. Research Marketing        B. Initiated to correct the problem with
   Act (1946)                   overproduction or surplus of goods
                                resulting from the Depression

3. Agricultural Adjustment   C. Provides yearly support to agricultural
   Act (1938)                   experiment stations in each state

Matching

1. Stephen Hales             A. Responsible for the initiation of
   (1677-1761)                  basic studies in plant anatomy and
                                morphology

2. Charles Darwin            B. Found that living things were made of
   (1809-1882)                  cells leading to the future of cytology

3. Marcello Malpighi         C. Demonstrated sexuality in plants,
   (1628-1694) and              thereby providing the roots of genetics
   Nehemiah Grew
   (1641-1712)

4. Rudolph Camerarius        D. Developed a simple yet elegant system
   (1665-1721)                  for the classification of plants
                                called binomial nomenclature

5. Linneaus (1707-1778)      E. Published "Vegetable Staticks," which
                                was the first significant publication
                                in plant physiology

6. Gregor Mendel             F. Showed that plants purify air
   (1822-1884)

7. Joseph Priestly           G. First to describe plant movement
   (1773-1804)                  in response to light and gravity

8. Robert Hooke              H. Founder of modern genetics
   (1635-1703)


Activities

1. Contact the U.S. Department of Agriculture in Washington, D.C., and find URLs for research currently being done at experiment stations located in the United States. Select two research projects of interest to you, summarize them, and specify why you feel that they are important.

2. Contact the U.S. National Research Initiative Program in Washington, D.C, and find the URLs summarizing research efforts that are currently being funded by this agency. Select two research projects of interest to you, summarize them, and explain why you feel that they are important.

3. Visit a supermarket and make a list of fresh fruits and vegetables available. Go through the store looking for all the ways in which two crops are processed (for example, apples and potatoes).

4. Visit a processing plant for commodities, such as tomatoes, apples, peaches, potatoes, or cotton, which may be found in your location. Summarize what you saw and why it was interesting or not interesting.

5. Visit a supermarket and look at the nutritional facts on processed fruits and vegetables, and then make a list of crops that you consider to be high, medium, and low in sugar, starch, and cholesterol.

References

Anderson, E. (1954). Plants, Man and Life. London: A. Melrose.

Berndt, R. M., & Berndt, C. (1970). Man, Land, and Myth in North Australia: The Gunwinnggu People. East Lansing: Michigan State University Press.

Cohen, M. (1977). The Food Crisis in Prehistory. New Haven, CT: Yale University Press. de Candolle, A. (1959). Origin of Cultivated Plants (2nd ed.). New York: Hafner. (Original work published 1886)

Harlan, J. R. (1976). The Plants and Animals which Nourish Man. Scientific American 235(3), 88-97.

Harlan, J. R. (1992). Crops and Man (2nd ed.). Madison, WI: American Society of Agronomy and Crop Science Society of America.

Saur, B. D. (1952). Agricultural Origins and Dispersals. Cambridge: M.I.T. Press.

Vavilov, N. I. (1926). Studies on the Origin of Cultivated Plants. Leningrad: Inst. Appl. Plant Breeding.
TABLE 2-1 BROAD DATES OUTLINING HUMAN PROGRESS IN THE
AREAS OF AGRICULTURE AND HORTICULTURE

Date Event

8000 B.C.  Domestication of edible plants.

3500 B.C.  Egyptians employed irrigation, pruning, and field
           cultivation using an oxen-pulled plow.

300 B.C.   Theophrastus (ca. 372-287 BC), the Father of Greek Botany,
           taught about plants from his own working knowledge of
           them. Text covers 550 kinds of plants. The rediscovery of
           his works in 1483 rekindle an interest in botany.

77 AD      Dioscorides, Father of Medicinal Botany, wrote a medical
           reference.

50-500     Grafting, budding, legume rotation, fertility appraisals,
           and cold storage of fruit practiced by the Romans.

500-1200   Dark Ages in Europe--Horticulture technologies preserved
           and practiced only in monasteries while flourishing in the
           Far East. Interest in horticulture began in Renaissance
           Italy as feudalism died out.

1492       Discovery of the New World. Broadening trade routes aid the
           transport and transplantation of new plant species.

1554       First written record of the tomato. Italians grew the plant
           by about 1550. Thomas Jefferson was the first American to
           grow tomatoes in 1781. George W. Carver dedicated to
           promoting the tomato and peanut.

1665       Robert Hooke detailed the structure of cork cells using a
           newly invented microscope.

1727       Stephen Hales's work in Vegetable Staticks represented the
           first significant publication in plant physiology. He
           explained some aspects of water uptake by roots, movement
           of liquid through plants, and evaporation of water from
           leaves. Hales was one of the first to use the equipment
           and methods of the physical sciences to study plants.

1739       About 500,000 people died in Ireland due to widespread crop
           failure of potatoes.

1747       Dr. James Lind experimented with sailors who had scurvy and
           discovered that consuming lemons and oranges for six days
           improved their health. Scurvy is a nutritional disease
           caused by inadequate vitamin C.

1774       Joseph Priestley reported that burning a candle in a closed
           container changes the quality of the atmosphere so that the
           flame is extinguished. Animals placed in that environment
           quickly die. A living mint sprig renews the air so a candle
           will burn.

1830       The first machine for cutting lawns was introduced by Edwin
           Budding. The machine was imported to the U.S. 25 years
           later.

1839       Salicylic acid (chemically related to salicin, the
           pain-relieving compound named for its source, Salix-willow)
           was isolated from the flowerbuds of a member of the rose
           family. In 1853, a number of synthetically prepared
           derivatives of this compound were prepared, one of which
           was acetylsalicylic acid. The Bayer Company selected that
           chemical as a substitute for salicylic acid and named it
           aspirin.

1847       Chocolate candy was first created.

1850       The mechanization of agriculture began. Mechanical reapers,
           the internal combustion engine, and the tractor altered the
           face of the world and the growth and increasing
           urbanization of the world population. Between 1860 and
           1920, about 1 billion acres of new land were brought under
           cultivation, with another 1 billion acres coming into
           production during the following six decades. Improvements
           in shipping, refrigeration, and processing further
           industrialized this process.

1859       Charles Darwin published On the Origin of Species by means
           of natural selection. The impact of Darwin's work has been
           significant in all areas of biology, including the search
           for natural relationships of plants and interpretations of
           plant adaptations and ecology.

1862       Congress passed bills constituting the U.S. Morrill
           Land Grant College Act and at this same time created the
           U.S. Department of Agriculture. Over 13 million acres of
           federal land were given to states to support the
           establishment of colleges for the agricultural and
           mechanical arts.

1866       Gregor Mendel discovered and published the basic
           patterns of inheritance and his understanding of the
           hereditary nature of variation between individuals in a
           population.

1869       A biologist imported European gypsy moth to the United
           States for study. A few of those insects escaped and
           established populations that have caused great devastation
           to Eastern forests.

1870       The Red Delicious apple is discovered in Iowa. The Golden
           apple originated on a farm in West Virginia in 1910.

1875       The first agricultural experiment station in the United
           States was established in Connecticut.

1880       Darwin published Power of Movement in Plants.

1882       Professor Millardet invented the Bordeaux mixture by adding
           lime to a copper sulfate spray, which caused the copper to
           precipitate and stick to the leaves. When applied to
           grapes, it deterred downy mildew.

1886       John S. Pemberton created Coca-Cola, a beverage using
           water, caramel, kola nut, sugar, vanilla, cinnamon, lime,
           and coca leaf extractions. By 1903, the makers began
           purging the coca leaf extract of its cocaine component.

1887       The Hatch Act established a yearly grant to support an
           agricultural experiment station in each state. The
           experiment station system became the basis for the U.S.
           Agricultural Extension Service.

1900       Liberty H. Bailey completes the compilation of a
           four-volume Cyclopedia of American Horticulture.

1917       Ford's Fordson tractor was introduced at $397.

1919       The publication of Inbreeding and Outbreeding by E. M. East
           and D. F. Jones gave scientific underpinnings to corn
           breeding and introduced Jones's system of double crossing
           through the use of four inbred lines. This work was one of
           the most significant early accomplishments of modern
           agricultural science.

1922       W. J. Robbins initiated plant tissue culture studies.

1922       Knudson published his asymbiotic method of seed germination
           "Nonsymbiotic Germination of Orchid Seeds" in Botanical
           Gazette. This technique revolutionized the propagation of
           orchids, both sexually and vegetatively. It led to
           techniques of mericloning and meristemming that are used
           widely for production of many crops today.

1939       Chemist Paul Muller discovered the insecticidal qualities
           of DDT, a compound first synthesized by German chemist
           Othmar Zeidler in 1874.

1947       Developed during World War II, the herbicide 2,4-D was
           introduced for weed control.

1961       Melvin Calvin was awarded the Nobel Prize for his work
           describing the light-independent reactions (often called
           the dark reactions, or the Calvin cycle) of the
           photosynthetic system.

1962       Rachael Carson published Silent Spring, spurring a new era
           of environmental concern and awareness.

1970       Norman Borlaug, Father of the Green Revolution, was awarded
           the Nobel Peace Prize for developing high-yielding dwarf
           strains of wheat that allowed tropical countries to double
           their wheat productivity.

1972       DDT (dichloro-diphenyl-trichloroethane) usage was banned in
           the United States.

1982       The first genetically engineered crop was developed, and by
           1994, the Flavr-Savr tomato became the first such plant
           approved for commercial marketing. The Flavr-Savr tomato
           was designed for slow fruit ripening and increased shelf
           life.

1983       Kary B. Mullis devised the polymerase chain reaction, a
           system to replicate large quantities of DNA from a small
           initial sample. The ability to create a large sample of DNA
           for testing and study had extraordinary impact on various
           fields of study, from areas of paleobiology to forensic
           analysis.

1983       Barbara McClintock received the Nobel Prize for her work
           with the complex color patterns of Indian corn, studies
           that revealed moveable genetic elements termed jumping
           genes.

TABLE 2-2 THIRTY MAJOR FOOD CROPS CULTIVATED TODAY
AND THE ANNUAL TONNAGE PRODUCED BY EACH

                                       Annual Production
* Crop                             (Millions of Metric Tons)

 1. Wheat                                    360
 2. Rice                                     320
 3. Maize                                    300
 4. Potato                                   300
 5. Barley                                   170
 6. Sweet Potato                             130
 7. Cassava                                  100
 8. Grapes                                    60
 9. Soybean                                   60
10. Oats                                      50
11. Sorghum                                   50
12. Sugarcane                                 50
13. Millets                                   45
14. Banana                                    35
15. Tomato                                    35
16. Sugar Beet                                30
17. Rye                                       30
18. Orange                                    30
19. Coconut                                   30
20. Cottonseed Oil                            25
21. Apples                                    20
22. Yam                                       20
23. Peanut                                    20
24. Watermelon                                20
25. Cabbage                                   15
26. Onion                                     15
27. Bean                                      10
28. Pea                                       10
29. Sunflower Seed                            10
30. Mango                                     10

* Thirty major crops used by humans (Harlan, 1976).
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Article Details
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Author:Arteca, Richard N.
Publication:Introduction to Horticultural Science
Article Type:Chronology
Geographic Code:1USA
Date:Jan 1, 2006
Words:7645
Next Article:Chapter 3 the horticulture industry: an important part of agriculture.
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