the importance of plant science - agriculture with...

The Importance of Plant Science

WHERE 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:

� Explain the importance of plant science.

Key Terms:

�

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

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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

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.

Horticulture is the produc-

tion 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. Floricul-

ture 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 pro-

ducing 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

and management goes into assur-

ing 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 catego-


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FIGURE 1. Field of wheat.

FIGURE 2. Logging at a tree farm.

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. Impor-

tant 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 activ-

ity 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

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, andNut 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


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FIGURE 3. Sugar cane field.

FIGURE 4. An apple orchard.

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 par-

allel 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 cof-

fee, tea, and cocoa, are typically grow in tropical areas. Herbs and spices are grown in small


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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 peo-

ple 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.

quantities throughout North Amer-

ica. 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 medi-

cines.

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 cof-

fee, 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


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FIGURE 5. A sunflower field.

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 com-

pound.

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 produc-

tion, 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. Illi-

nois 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 market-

ing of crops.

Summary:

� Plant science is the study of the structure, functions, growth, and protection ofplants. Plant science can be divided into three major segments—agronomy, horti-culture, and forestry.


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Most of the important plants have been domesticated. The important field and hor-ticultural 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. Afew 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. Approxi-mately 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 19.2percent 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:

� Research the origins of major agricultural crops. Identify where they were firstdomesticated 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


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