integrated pest management - agricultural...

Integrated Pest Management

PEST DAMAGE to U.S. agriculturalcrops has been estimated to be 33

percent of the total crop productionpotential, which is a great loss of foodand fiber that could be put to humanuse. Also, it is a huge economic loss.To reduce losses, carefully plannedstrategies must be employed to limitpest damage.

Objective:

� Explain integrated pest management.

Key Terms:

�

E-unit: Integrated Pest Management

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abiotic

bacteria

biological control

biotic

causal agent

chemical control

clean culture

cultural control

disease triangle

economic injury level

economic threshold

eradication

fumigant

fungi

fungicides

genetic control

herbicides

hyphae

infectious diseases

insecticides

insects

integrated pestmanagement (IPM)

key pest

mechanical control

mites

miticides

molluscicides

mycelium

nematocides

nematodes

noninfectious diseases

parasitic plants

pathogens

pest

pest populationequilibrium

pest resurgence

pesticides

pesticide resistance

plant disease

quarantine

regulatory control

rodenticides

targeted pest

trap crop

viruses

weeds

The Importance ofIntegrated Pest Management

Integrated pest management (IPM) is an organized program in which the best man-

agement methods available are used to keep pest populations below the economic injury level.

Also, IPM is used to avoid adverse effects to humans, wildlife, and the environment. IPM is a

pest-control strategy that relies on multiple control practices. It establishes the amount of dam-

age that will be tolerated before control actions are taken.

The key to a successful IPM program is the use of a scout (the grower or a hired individual)

who regularly monitors pest populations and crop conditions. The scout collects data about the

pests that are causing damage, the pests’ current life stages, and if the pest population is

increasing or decreasing. Knowing how to identify a key pest (a pest that occurs on a regular

basis for a given crop) and its biological characteristics is important because the weakest link in

each pest’s biology must be found for successful pest management.

An understanding of the crop’s biology and its ecosystem is essential for successful IPM.

The crop’s ecosystem consists of the biotic and abiotic influences in its living environment.

The biotic components are the living organisms, such as plants and animals. The abiotic

components are nonliving factors, such as soil and water.

IPM attempts to understand the influence of ecosystem manipulation on lowering pest

populations. Pest population equilibrium occurs when the numbers of a pest stabilizes or

remains steady.

TYPES OF PESTS

An understanding of the major pest groups and

their biology is required to ensure success in reducing

crop losses due to pests. A pest is a living organism

that can cause injury or loss to a plant. Pests include

insects, diseases, weeds, mites, nematodes, parasites,

and animals.

Insects

Insects are a group of animals with an exoskeleton

and three body parts. Most insects have six legs and

four wings. At this time, more than 800,000 kinds of

insects have been identified. Due to the ability to pro-

duce large numbers of offspring in a short time,

insects can cause economic loss by feeding on horti-

cultural crops.

Insects have chewing or sucking mouthparts. Dam-

age symptoms caused by chewing insects are leaf defo-


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FIGURE 1. Insects caused considerable damage

to this corn plant.

liation, leaf mining, stem boring, and root feeding. Insects with sucking mouthparts produce

distorted plant growth, leaf stippling, and leaf burn.

As an insect grows from an egg to an adult, it passes through several growth stages called

metamorphosis. There are two types of metamorphosis: incomplete and complete. Incomplete

metamorphosis consists of three life stages: egg, nymph, and adult. As a nymph, the insect

grows and passes through several instars between molts. Each time the insect molts or sheds its

exoskeleton, it passes into the next instar. Complete metamorphosis consists of four life stages:

egg, larva, pupa, and adult. The larva stage is the period when the insect grows. The pupa stage

is a resting period where a dramatic morphological change from larva to adult occurs.

Plant Diseases

A plant disease is a disturbance to normal plant growth and development. Diseases are

generally classified as infectious or noninfectious. Infectious diseases are caused by living

organisms (bacteria, fungi, and viruses) that are often referred to as disease pathogens. An

infectious disease can be spread to other plants. In contrast, noninfectious diseases are

caused by environmental imbalances and cannot be spread to other plants. Examples of nonin-

fectious disease include over watering, nutrient deficiencies, and air pollution damage.

Plants are most susceptible to disease when under stress, which is usually associated with

environmental factors. While the environmental condition itself may or may not cause a non-

infectious disease, the stress it creates can reduce a plant’s ability to fight off infectious disease.

For instance, over watering can cause the death of root tissues, but it also weakens the plants

defenses against soil-borne disease organisms.

The occurrence and severity of infectious plant diseases is based on three factors. A suscep-

tible plant or host must be present. The causal agent or organism that produces a disease

must be present, and the environmental conditions conducive to the causal agent must occur.

The relationship of these three

factors is the disease triangle.

Disease-control programs are

designed to affect each or all of

these factors.

Fungi are a principal cause of

plant disease. Fungi are

eukaryotic organisms (organisms

whose cells are organized into

complex structures by internal

membranes) that are members of

the kingdom Fungi. They absorb

nutrients from living or dead

organisms, and their bodies con-

sist of thread-like vegetative struc-

tures known as hyphae. When

grouped together, hyphae is called

mycelium. Fungi can reproduce


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FIGURE 2. The blight on this tomato is known as a fungus. (Courtesy, Jackie

Mullen, Auburn University)

and cause disease by producing spores or mycelia. The fungus can produce spores asexually or

sexually.

Bacteria are one-celled microscopic organisms. Individual bacteria have a wide range of

shapes. They are found in every Earth habitat and can enter a plant only through wounds or

natural openings.

Viruses are composed of nucleic acids surrounded by protein sheaths. They are capable of

altering a plant’s metabolism by affecting protein synthesis. Plant viruses are transmitted by

seeds, insects, nematodes, fungi, and mechanical means. Viral diseases produce several symp-

toms including ring spots, stunting, malformations, and mosaics. A mosaic symptom is a leaf

pattern of light and dark green color.

Weeds

Weeds are plants that are undesirable and are often considered out of place. Weeds com-

pete with crops for growth essentials: space, nutrients, water, and light. They also harbor insect

pests.

Other Pests

Plants suffer from a variety of other pests including mites, nematodes, parasitic plants, and

mammals. Mites are small organisms with an exoskeleton, two body parts, and eight legs.

Nematodes are tiny hair-like roundworms that feed on plant roots. They may live in the

soil or water, within insects, or as plant or animal parasites. Nematodes are quite small and

produce damage to plants by feeding on roots, stems, or leaf tissue. Some plants (e.g., dodder

and mistletoe) are parasitic. Parasitic plants extract water and nutrients from other plants


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FIGURE 3. This out-of-place sunflower is robbing nutrients from nearby crop

plants.

FIGURE 4. Nematodes are extremely

small pests that can destroy plant roots.

(Courtesy, Frank Killebrew, Mississippi

State University)

and give nothing in return. Mammals including deer, mice, rabbits, and voles cause severe

physical damage to plants, which often causes plant death.

ECONOMIC LOSSES

The estimated pest damage to U.S. agricultural crops amounts to one-third of the total crop

production potential. Methods are available to minimize or eliminate the losses that pests

cause, but the goal of managing pest populations is to keep losses below a level where profit is

reduced.

The economic injury level is the point at which the cost of pest control equals the reve-

nue loss caused by a pest. Economic injury level is determined by estimating the potential yield

loss, the value of the crop, and the cost of treatment. The economic injury level clearly defines

how much damage can be tolerated.

The economic threshold is the number of insects per plant or the amount of damage to

the plant that economically justifies the use of control measures. If a control is applied when a

pest population reaches the economic threshold, the population will be suppressed before the

economic injury level is reached.

BENEFITS OF INTEGRATED PEST MANAGEMENT

There are many benefits of integrated pest management (IPM) to agriculture and to the

environment. These benefits help sustain the ability of the earth to meet the needs of an

increasing human population.

Benefits of IPM to the Agriculture Industry

1. Reduced pesticide costs—Fewer pesticides are used with IPM. As a result, the cost of

pesticide is reduced, and less equipment is needed.

2. Reduced application costs—The cost of labor for pesticide application is reduced due to

less time needed.

3. Less pesticide resistance—Insects, weeds, and other pests will be less likely to develop

pesticide resistance, which means that a pesticide is more effective when its use is

required.

Benefits of IPM to the Environment

1. Reduced contamination—The environment suffers less degradation through the use of

IPM. Pesticide residues do not build up in soil, water, and other natural resources.

2. Fewer residues on food—Food products will have less pesticide residue with IPM,

which reduces the chance of people contracting diseases associated with pesticides.


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3. Improved human health—IPM contributes to food products that promote good health.

Cancer-causing residues from agricultural chemicals are present in smaller amounts or

are not on food at all.

COMPONENTS OF IPM

The reason for using IPM methods of pest control and crop protection is that reliance on

chemicals as the only means of pest control can lead to pest resistance, pest resurgence, and

possible harmful effects to humans and the environment.

IPM uses chemical and nonchemical control methods to help reduce losses from pests.

Choosing which method or methods to use will depend on an accurate assessment of the

problem as well as information about the crop, the field, and the type of management. IPM

methods include biological, chemical, cultural, genetic, and mechanical control.

Biological Control

Biological control is the use

of living organisms to reduce pest

populations. These beneficial

organisms are natural enemies of

pests. They attach, live in, or

infect pest hosts. Parasites, preda-

tors, and pathogens are all used as

biological controls.

Chemical Control

Chemical control is an inte-

gral part of an IPM program and

is the use of pesticides to reduce

pest populations. Pesticide

resistance is the ability of an

organism to tolerate a lethal level

of a pesticide. Pest resurgence

refers to a pest’s ability to repopu-

late after control measures have

been eliminated or reduced.

Pesticides are the most danger-

ous means of pest control in

terms of risks to the environment

and to humans. Even highly

trained applicators must be

extremely cautious when using

pesticides.


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FIGURE 5. Using parasitic wasps to control pest populations is known as

biological control. (Courtesy, Agricultural Research Service, USDA)

FIGURE 6. Using chemicals to destroy pests is a form of chemical control.

Cultural Control

Cultural control is used to make the crop environment unsuitable for pests to feed, live,

or reproduce. In addition, cultural control helps to improve the crop’s health. Examples of cul-

tural controls include soil tillage, crop rotation, the adjustment of harvest or planting dates,

irrigation schemes, variety selection, clean culture, and trap crops. Clean culture refers to

any practice that removes the breeding or over-wintering sites of a pest. A trap crop is a sus-

ceptible crop planted to attract a pest to a localized area. After the pest arrives, the trap crop is

destroyed or treated with a pesticide.

Genetic Control

Genetic control involves the use of genetically engineered organisms to fight pests. Plant

breeders are constantly working to develop varieties and hybrids that are resistant to or tolerant

of pests.

Mechanical Control

Mechanical control is used to physically remove or exclude pests. It includes hand

destruction as well as the use of screens to keep out insects and traps to catch them.

Federal and state governments have created laws that prevent the entry or spread of known

pests into uninfested areas, which is referred to as regulatory control.

Regulatory agencies also attempt to contain or eradicate certain types of pest infestations.

The Plant Quarantine Act of 1912 provides for inspection at ports of entry. Plant or animal

quarantines are implemented if shipments are infested with targeted pests. Quarantine is the

isolation of pest-infested material. A targeted pest is a pest that, if introduced, poses a major

economic threat. If a targeted pest becomes established, an eradication program will be started.

Eradication means total removal or destruction of a pest, which is extremely difficult and

expensive to administer.

Pesticide Classes

Using chemicals to manage pests and diseases is referred to as chemical control. Pesti-

cides are the materials used to control pests. These chemicals may be natural or man-made.

Although once used almost exclusively, pesticides are now viewed as only one component of

an IPM program. In fact, chemical pesticides often are used only when it is absolutely neces-

sary. Pesticide application must be done safely to reduce potential injury to people and the

environment. The different types of pesticide are classified according to the pest(s) they con-

trol.

Insecticides are used to control insects. Making body contact with the chemical, swallow-

ing the insecticide, or inhaling it (enabling it to enter through the respiratory system) will

result in insect death.

Miticides are used to control mites and ticks, which are usually killed by coming in contact

with the chemical.


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Fungicides are used to control fungal diseases. Fungicides are used to prevent a plant from

becoming infected with the disease. Therefore, they are applied before the disease is present.

Herbicides are used to kill unwanted plants.

Rodenticides kill rodents, such as rats and mice. These chemicals are usually applied as

bait. Eating the chemical poisons the rodents.

Nematocides kill nematodes. Nematocides are usually applied in the form of a fumi-

gant, which is a substance that produces a smoke, vapor, or gas when applied.

Molluscicides are used to kill slugs and snails. These chemicals are usually applied as bait,

which attracts the slugs and snails and poisons them.

Summary:

� Integrated pest management (IPM) is an organized program in which the best man-agement methods available are used to keep pest populations below the economicinjury level. Also, PMI is used to avoid adverse effects on humans, wildlife, and theenvironment.

A pest is a living organism that can cause injury or loss to a plant. Pests includeinsects, diseases, weeds, mites, nematodes, parasites, and animals.

The goal of managing pest populations is to keep losses below a level where profit isreduced.

Benefits of IPM to agriculture and the environment include reduced pesticide costs,reduced application costs, less pesticide resistance, reduced contamination, fewerresidues on food, and improved human health.

IPM methods include biological, chemical, cultural, mechanical, and genetic con-trol.

Pesticides are the materials used to control pests. Pesticide classes include insecti-cides, miticides, fungicides, herbicides, rodenticides, nematocides, andmolluscicides.

Checking Your Knowledge:

� 1. What is integrated pest management?

2. What are the types of plant pests?

3. How are economics tied to integrated pest management?

4. What are some benefits to integrated pest management?

5. What methods of control are involved in integrated pest management?


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Expanding Your Knowledge:

� Compile a list of cultural practices that could be employed to reduce pest problemsfor a crop of your choice. Possible crops include an orchard crop, a field crop, alawn, a vegetable garden, or a greenhouse crop.

Web Links:

� Integrated Pest Management

http://www.ipm.uiuc.edu/


http://www.dec.state.ak.us/eh/pest/ipm.htm


http://en.wikipedia.org/wiki/Integrated_pest_management

Integrated Pest Management Principles

http://www.epa.gov/opp00001/factsheets/ipm.htm


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http://www.ipm.uiuc.edu/

http://www.dec.state.ak.us/eh/pest/ipm.htm

http://en.wikipedia.org/wiki/Integrated_pest_management

http://www.epa.gov/opp00001/factsheets/ipm.htm

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