Transcript Horticulture Science

Horticulture Science
Lesson 31
Understanding Integrated
Pest Management
Interest Approach
Begin the lesson by having students read a newspaper
article about pesticides found in a groundwater supply.
Ask students for ways they believe this problem
can be stopped. Indicate that chemical pesticides are
useful tools for horticulturists, but pesticides must be
used wisely. Tell them that there are many other means
by which to control the pest populations.
Student Learning Objectives
•Explain integrated pest
management.
•Identify and describe the types
of pests.
Student Learning Objectives
•Identify the basic elements of
an integrated pest management
program.
Terms
• annual weed
• bacteria
• best management practices
(BMPs)
• biennial weed
• biological control
• broadleaf weeds
• causal agent
• chemical control
Terms
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cultural/physical control
disease triangle
economic injury level
economic threshold
fungi
grass weeds
infectious diseases
insects
Terms
•integrated pest management
(IPM)
• mites
• nematodes
• noninfectious diseases
• parasitic plants
• pathogens
• perennial weed
Terms
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pest
pesticides
plant disease
sanitation
scouting
viruses
weeds
What is integrated pest
management?
• Integrated pest management (IPM)
is a pest management strategy that uses
a combination of best management
practices (BMP) to reduce pest damage
with the least disruption to the
environment.
• Best management practices (BMPs)
are those practices that combine scientific
research with practical knowledge to
optimize production and increase crop
quality while maintaining environmental
integrity.
What is integrated pest
management?
• IPM provides protection against hazards
to humans, domestic animals, plants, and
the environment.
• Studies have shown that no single control
measure works consistently over a long
period of time.
• A reason for this is that pests can
develop resistance to certain control
measures.
What is integrated pest
management?
• The goal of IPM is to keep pest
populations below the economic or
aesthetic injury level.
1. Economic injury level is the point at
which the cost of pest control equals the
revenue loss caused by a pest.
– It is determined by estimating the potential
yield loss, the value of the crop, and the cost
of treatment.
– Economic injury level also clearly defines how
much damage can be tolerated.
What is integrated pest
management?
2. 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 it
reaches the economic injury level.
What is integrated pest
management?
• The key to a successful IPM program is
scouting, which involves regularly
monitoring pest populations and crop
conditions.
• A scout collects data about which pests
are causing damage, what stage of life
each pest is in, and whether the pest
population is increasing or decreasing.
• Knowing how to identify key pests and
their biological characteristics is
important.
What is integrated pest
management?
• The weakest link in each pest’s biology
must be found if management of the pest
is to be successful.
What is integrated pest
management?
• Benefits of IPM help sustain the ability of
the earth to meet the needs of an
increasing human population.
1. The benefits to horticulture vary with
the crop and the extent to which pests
interfere with economical production.
– Careful planning is required to make effective
use of IPM.
What is integrated pest
management?
• The benefits of IPM to the
horticulture industry:
a. There are reduced pesticide costs in
addition to fewer pesticides used with
IPM.
b. Application costs are reduced due to
time, and the cost of labor for pesticide
application is reduced.
c. Less pesticide resistance develops
within populations of insects, weeds, and
diseases.
What is integrated pest
management?
2. IPM also benefits the environment, which
is made more sustainable and friendly to
people.
• Benefits of IPM to the environment:
a. Reduced contamination and degradation of the
environment occurs through the use of IPM.
– Pesticide residues do not build up in soil, water, and other
natural resources.
b. Cancer-causing residues are present in smaller
amounts or are not on food at all.
– Less pesticide residue on food products means a
decreased chance of people ingesting pesticides.
How are the types of pests
identified and described?
• 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.
How are the types of pests
identified and described?
• Insects are a group of animals with an
exoskeleton and three body parts.
• Most insects have six legs and four
wings.
• More than 800,000 kinds of insects have
been identified.
• Insects are capable of producing large
numbers of offspring in a short time and
can cause economical loss by feeding on
horticultural crops.
How are the types of pests
identified and described?
1. Insects have either chewing or sucking
mouthparts.
– Damage symptoms caused by chewing insects
are leaf defoliation, leaf mining, stem boring,
and root feeding.
– Insects with sucking mouthparts produce
distorted plant growth, leaf stippling, and leaf
burn.
How are the types of pests
identified and described?
How are the types of pests
identified and described?
2. As an insect grows
from an egg to an
adult, it passes through
several growth stages,
which is called
metamorphosis.
– Two types of
metamorphosis exist:
incomplete and
complete.
How are the types of pests
identified and described?
a. 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.
How are the types of pests
identified and described?
• b. Complete metamorphosis consists of
four life stages: egg, larva, pupa, and
adult.
• The larva stage is
the period when the
insect grows.
• The pupa is a
resting period where
a dramatic
morphological
change from larva to
adult occurs.
How are the types of pests
identified and described?
• A plant disease is defined as a
disturbance to the normal growth and
development of a plant.
– Diseases are generally classified as being
infectious or noninfectious.
• Infectious diseases are caused by
living organisms such as bacteria, fungi,
or virus, which are often referred to as
disease pathogens.
– An infectious disease can be spread to other
plants.
How are the types of pests
identified and described?
• Noninfectious diseases are caused by
environmental imbalances and cannot be
spread to other plants.
– Noninfectious disease examples include over
watering, nutrient deficiencies, and air
pollution damage.
– Plants are most susceptible to disease when
they are under some type of stress.
– The stress is usually associated with
environmental factors.
How are the types of pests
identified and described?
1. The occurrence and severity of infectious
plant diseases is based on three factors.
• A susceptible plant or host must be present.
• The causal agent or organism that
produces a disease must be present.
• Environmental conditions conducive to the
causal agent must occur.
– The relationship of these three factors is known
as the disease triangle.
– Disease control programs are designed to affect
each or all of these factors.
How are the types of pests
identified and described?
How are the types of pests
identified and described?
2. Fungi are a principal cause of plant
disease.
• Fungi are organisms that lack chlorophyll.
– They absorb nutrients from living or dead
organisms.
– Their bodies consist of threadlike vegetative
structures known as hyphae.
– When hyphae are grouped together, they are
called mycelium.
– Fungi can reproduce and cause disease by
producing spores or mycelia.
– The fungus can produce spores asexually or
sexually.
How are the types of pests
identified and described?
3. Bacteria are onecelled or unicellular
microscopic
organisms.
– Bacteria can enter a
plant only through
wounds or natural
openings.
How are the types of pests
identified and described?
4. 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 symptoms
including ring spots, stunting, malformations,
and mosaics.
– A mosaic symptom is a leaf pattern of light
and dark green color.
How are the types of pests
identified and described?
• Weeds are plants that are undesirable and
are often considered out of place.
– Weeds compete for space, nutrients, water, and
light that the crop plants need to grow.
– They also harbor insect pests.
– Weed life cycles are annuals, biennials, and
perennials.
– They are also classified as broadleaf or grass
weeds.
1. An annual weed is a plant that
completes its life cycle within one
growing season.
How are the types of pests
identified and described?
2. A biennial weed is a plant that will
live for two growing seasons.
– Vegetative growth occurs in the first year
where the plant produces leaf, stems, and
root tissue.
– During the second year, the plant flowers and
produces seeds.
3. A perennial weed can live for more
than two growing seasons and may
reproduce by seed and/or vegetative
growth.
How are the types of pests
identified and described?
4. Broadleaf weeds have a broad leaf
associated with dicot plants.
– Examples are dandelions, ground ivy,
plantain, and spurge.
5. Grass weeds include monocots such
as crabgrass, nimblewill, and quackgrass.
How are the types of pests
identified and described?
• Plants suffer from a variety of other pests
including mites, nematodes, parasitic plants,
and animals.
1. Mites are small organisms with an
exoskeleton, two body parts, and eight legs.
2. Nematodes are tiny hair-like roundworms
that feed on the root of plants.
– They may live in the soil or water, within insects, or as
parasites of plants or animal
– Nematodes are quite small and
produce damage to plants by feeding
on roots, stems, or leaf tissue.
How are the types of pests
identified and described?
3. Some plants, such as dodder and
mistletoe, are parasitic.
– Parasitic plants extract water and nutrients
from other plants and give nothing in return.
4. Animals including deer, mice, rabbits,
and voles cause severe physical damage
to plants, which often causes plant death.
What are the basic elements of an
integrated pest management
program?
• For successful management of pests, the
IPM program must be a year-round
program.
• Also, IPM control measures for a specific
crop, poinsettias for example, should
begin before the plants enter the
greenhouse.
• The strength of IPM is the combination of
control measures used.
• Four broad areas of control include
sanitation, cultural/physical control,
biological control, and chemical control.
What are the basic elements of an
integrated pest management
program?
• Many pest problems can be greatly
reduced, if not eliminated, with
sanitation.
• Sanitation is simply the effort made to
keep a greenhouse or garden clean.
• Many insects and diseases can be found
in plant debris.
• Sanitation involves the removal of weeds
from the immediate area around crops.
What are the basic elements of an
integrated pest management
program?
• Cultural/physical control methods are
those methods that physically prevent
activities of pests.
– Used alone they probably will not provide
complete control of pests and reduce certain
problems.
– Cultural/physical controls are also safe to
humans and relatively easy to implement.
1. Stop the introduction of pests to the
greenhouse when possible.
2. Remove and destroy heavily infested
and diseased plants.
What are the basic elements of an
integrated pest management
program?
3. Maintain optimal cultural requirements
for each crop (growing medium,
watering, fertility, temperatures, etc.) to
promote healthy growth.
4. Fungal diseases can be reduced by
providing good air circulation around the
plants.
5. The yellow sticky traps
used as monitoring tools
also serve as a means of
physical control.
What are the basic elements of an
integrated pest management
program?
• Biological controls involve the use of
living organisms to control pests.
– They maybe microbial organisms, parasitic
organisms, or predators.
– Biological control organisms for greenhouse
use are found in nature and are considered
environmentally safe.
1. A bacterium, Bacillus thurengiensis,
effectively controls caterpillars.
– Aphids and whitefly can be controlled to an
extent by species of bacteria and fungi.
– The bacteria and fungi are natural diseases of
those insects.
What are the basic elements of an
integrated pest management
program?
2. Parasitic organisms help to control some
pests.
– The parasites are natural enemies of the pest and live
off the pest organism.
– An example is a tiny parasitic wasp that lays its eggs
on the whitefly larva that feeds on plant leaves.
– The eggs hatch with the wasp larva inside the whitefly
larva.
– The wasp larva proceeds to eat the whitefly larva.
– The wasp matures, emerges from what is left of the
whitefly, mates, and looks for whitefly larva on which
to lie the next generation of eggs.
What are the basic elements of an
integrated pest management
program?
3. Predatory organisms can be released
to devour certain plant pests.
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A beetle attacks whitefly larva and adults.
A mite is used to control thrips.
Ladybugs eat aphids.
As with parasitic organisms, chemical
pesticides should not be used with predatory
organisms.
– Also, predatory and parasitic organisms
should be released when pest populations are
small.
What are the basic elements of an
integrated pest management
program?
• The use of chemicals to control pests
and diseases is chemical control.
– The chemicals used are called pesticides.
– Although once used almost exclusively,
control of pests with the use of pesticides is
now viewed as only one component of an IPM
program.
– In fact, use of chemical pesticides is now
often done only when absolutely necessary.
– Application of pesticides must be done safely
to reduce potential injury to people and the
environment.
Review/Summary
•What is integrated pest
management?
•How are the types of pests
identified and described?
Review/Summary
•What are the basic elements of
an integrated pest management
program?