Download Weeds, Bugs and other Pest

WEEDS, BUGS AND
OTHER PEST
Weeds
•Weed-plants that are considered to be growing
out of place.
•What is a weed to some is not a weed to others
•The key is where it is growing
•Undesirable plants
• They compete with desired plants for water,
nutrients, light and space.
• They decrease crop quality
• They reduce aesthetic value
• They interfere with maintenance along right-of-ways
• They harbor insects and disease pathogens
Annual Weeds
Prickly Lettuce
Common Chickweed
Annual Weed-a plant that completes its life cycle
within one year.
Two Types of annual weeds
Winter annual-germinates in the fall and actively grows until
late spring
Summer annual-germinates in the late spring and grows in
hot summer months
Biennial Weeds-are weeds that live for 2 years.
First year only produces vegetative growth-leaves, stem and root
tissue
Second year produces seeds and flowers and then dies.
Wild Carrot
Bull Thistle
Burdock
Perennial Weeds-can live for more then two years and may
reproduce by seed and/or vegetative growth.
Rhizomes-a stem that runs underground and gives rise to
new plants at each joint (node).
Stolen-a stem that runs on the surface of the ground and
gives rise to new plants at each node.
Canada Thistle
Bermuda Grass
Dandelion
Noxious Weeds
Noxious Weed-a plant that causes great harm to other
organisms by weakening those around it.
Most states have a noxious weeds list.
Great effort is made to control or eradicate
Can be very difficult to kill and need several
treatments of herbicides
Spread by various methods
Seeds become airborne
Seeds enter flowing waterways
Seeds become attached to humans or animals and
travel
Seeds are eaten and distributed by birds
Idaho Department of Agriculture has a list of 64 noxious weeds. The
State is divided into 30 Cooperative Weed Management Areas (CWMA).
In each of these areas land owners and government agencies work
together to ensure that noxious weeds are controlled and eradicated.
Yellow Devil Hawkweed
Black Henbane
Knotweed
Puncture vine
Buffalobur
Diseases
Plant disease is ANY abnormal plant growth.
Plant diseases are more the rule then exception
Most plants tolerate the diseases
There are two types of disease causing agents
Abiotic (nonliving)
Nutrient deficiencies
Water stress
Temperature stress
Combination of water and temp stress
Biotic (living)
Fungi
Bacteria
Viruses
Nematodes
It is important to understand the difference between infectious
diseases caused by biotic agents and noninfectious diseases
caused by abiotic diseases.
There are various symptoms caused by the pathogens on plants:
Dwarfing of growth
Yellowing of foliage
Leaf spotting
Blasting of grain heads
Stem cankers
Fruit rot
Seed decay
Destruction of seedlings
Wilt
Defoliation
Root rot
Galls
Growers need to know what the symptoms are and the causes to
be able to effectively treat and eradicate the disease.
Disease Triangle
The occurrence and severity of the plant disease is based on the
following factors:
1. A susceptible plant or host must be present
2. The pathogen organism, or causal agent, must be present. A
casual agent is an organism that produces a disease.
3. Environmental conditions conducive to support the causal
agent must occur.
The relationship between these factors is known as the disease triangle
*Understanding how the relationship works is how we can effectively
treat plant diseases and learn to stop the growth of the new diseases.
Fungi are the principal causes of plant diseases.
Fungi are plants that lack chlorophyll.
Fungi causes diseases by producing spores or mycelium
These spores can be dispersed by wind, water, insects and
humans.
Bacteria: one-celled or unicellular microscopic plants.
Bacteria can enter a plant only through wounds or natural
openings.
Bacterial diseases are the causes for things like stem and root
rot as well as many blights.
Viruses: pathogenic or disease-causing, organisms
Viruses are composed of nucleic acids surrounded by protein
sheaths. They effect the plant’s metabolism by effecting
protein synthesis. Plant viruses are transmitted by seeds,
insects, nematodes, fungi, grafting and mechanical means,
including sap contact. Produces several well-known symptomsa visible change to the host. Symptoms include ring-spots,
stunting, malformations and mosaics-light and dark green leaf
patterns.
Nematodes: tiny roundworms that live in the soil or water, within
insects, or as parasites of plants or animals. These parasites are very
small and produce damage by feeding on the host plant. Main
symptom is plant growth issues from feeding on the roots and stems.
Other Pest
Invertebrate pest: organisms that do NOT have a
vertebrate.
Insects, nematodes, snails and slugs
Insects have three body parts: head, thorax and abdomen
and have 6 legs.
Ticks, mites and spiders have only two body parts and 8
legs.