Transcript Introduction to Plant Pests

Introduction to Plant Pests
Margaret
Chapman
Cal Poly,
San Luis Obispo
AgEd 410
Spring 1999
Modified by Georgia Agricultural Education Curriculum Office
July, 2002
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Four main groups of plant
pests:
1. Weeds
2. Invertebrates
3. Vertebrates
4. Disease Agents
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Plant Pests
* Organisms that compete with
people for food or fiber, interfere
with raising our crops and
livestock.
* Proper identification is important
in controlling pests.
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Weeds
* Undesirable plants, sometimes
defined as “any plant growing out
of place.”
* Adapt well to local
climates and soils and
can compete successfully
with cultivated plants.
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* Most weeds
produce a large
number of seeds.
* Some weed seeds
can remain dormant
for 20 years before
germinating.
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* Weeds can be persistent and difficult
to eradicate, because some have
vegetative means of reproduction in
addition to seeds.
* Weeds compete with
agricultural crops for
water, nutrients, light
and space.
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* Weeds can interfere with farming
operations, and can harbor insects
and plant diseases.
* Some weeds are toxic to livestock.
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* A simple way to identify
weeds is to compare them
to colored photographs and
drawings.
* Become familiar with
plant classification system
and the weeds physical
features, developmental
stages,and life cycles.
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* We will discuss
weed and other pest
control measures in
upcoming lessons.
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Invertebrate Pests
* Includes insects and their relatives,
nematodes, snails and slugs.
* “Invertebrate” signifies animals
without backbones (no vertebrate).
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* Insects have three body parts: head,
thorax and abdomen and six legs.
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* Ticks, mites and spiders have only
two body parts and eight legs.
Spider
Tick
Mite
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* Nematodes are a large group of
unsegmented worms that can be
plant parasites.
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* Snails and slugs are mollusks that
prefer cool, moist surroundings.
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Vertebrates
* Animals with backbones
* Includes fish ,amphibians, reptiles,
birds and mammals.
* Most of our concern is with birds
and mammals.
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Pest birds
* Harbor pathogens, disease
causing organisms
* Eat or damage crops
* Cause damage to buildings
* Make too much noise
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* Rodents are mammals that interfere
with people, or cause harm to crops
and livestock.
* Animal pests are similar to weeds,
those that are out of place are considered
pests.
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Most of our vertebrate problems
are caused from:
* Rats
* Mice
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* Squirrels
Disease Agents
* Cause disease in plants and animals.
* Many are submicroscopic, making
identification difficult.
* If you can’t see the pest, then it may
be identified by the type of symptoms
caused or damage done.
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* Included in this group of pests are:
1. Bacteria
Bacterial citrus canker
symptoms on citrus leaves
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2. Fungi
* Scab symptoms on
orange fruit caused by the
fungus Elsinoe fawcetti
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3. Viruses
* Potato Virus on
veins and shoots
* Citrus tristeza Virus
on grapefruit
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Problems growers face
* Energy, time and expense to combat
problems.
* Losses of food to our world food supply
can become disastrous.
* Farmers are focusing on controlling
pests while dealing with environmental
pollution problems.
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* New methods and concepts continue to
evolve each day to keep our crops healthy
and abundant.
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