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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.
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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
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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.
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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.
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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
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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.
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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
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