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CCOG for LAT 250 Winter 2022

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Course Number:
LAT 250
Course Title:
Plant Diseases, Insects and Weed Identification
Credit Hours:
Lecture Hours:
Lecture/Lab Hours:
Lab Hours:

Course Description

Covers the identification of common diseases, insects, and weeds that affect the normal development of horticultural plants. Introduces control options for managing diseases, insects and weeds. Audit available.

Addendum to Course Description

Symptoms of damage to plants by specific diseases, specific insects and damage caused by them and identification of specific weeds common to this area are shown. The emphasis is correct identification more than specific pesticides used for control.  This course is intended as a follow-up to the first year course, PESTICIDES LAT 104, which focuses on specific pesticides.

Intended Outcomes for the course

Upon completion of the course students should be able to:

  • Identify common pest problems.
  • Apply appropriate pest control strategies. 

Course Activities and Design

The Instructor prepares hands-on labs before class (e.g. prepares exercises, and scouts to find weeds, insects and disease examples on campus). During the lab period, the Instructor teaches weed, insect, and disease identification skills through active lecture/demonstrations in real time at each specimen weed, insect or disease.  The instructor designs new lab materials and class exercises for each class, based on what is available in the field that day.   The students prepare a weed collection or IPM report  and the Instructor evaluates the reports outside of class time - providing a score and feedback on technical accuracy and completeness. eli

Outcome Assessment Strategies

This is a graded course. Grades are based on exams in the field dealing with specific pests. Exams include being able to identify specific diseases, insects and weeds by name and include the pests particular life cycle.

Course Content (Themes, Concepts, Issues and Skills)

1.0  Identification of diseases
1.1.0  Fungal pathogenic diseases.
1.1.1  Conditions favorable for disease development.
a.  Relative humidity
b.  Moisture
c.  Temperature range
1.1.2  Spore availability
a.   Wind borne
b.   Soil borne
1.1.3  Susceptibility of host plants
a.   Highly susceptible
b.   Moderate susceptibility
c.   Resistant
d.   Highly resistant
1.1.4  Symptoms of damage by fungi
a.   Leaf spot fungi
b.   Holes in leaves
c.   Burned foliage
d.   Galled leaves
e.   Distorted leaves
f.   Discolored leaves
g.   Defoliation
h.   Dead twigs and branches
I.   Galled stems, branches and trunks
j.   Sunken stem tissue
k. Damage to flowers
l.   Damage to fruit
m.   Damage to roots
1.1.5  Seriousness of specific diseases
a.   Slight damage
b.   Moderate damage
c.   Severe damage causing death
1.1.6  Period of activity
a.   Spring
b.   Summer
c.   Fall
d.   Winter
1.1.7  Damage to specific hosts
a.   Plants known to be affected
b.   Variables in symptoms of plants affected
1.1.8  Control measures
a.   Removal
b.   Pruning
c.   Fertilizing
e.   Leaf removal
f.   Improve drainage
g.   Reduce watering
h.   Fungicides
1.1.9  Fungicides
a.   Phytotoxicity
b.   Proper selection based on fungus disease
c.   Timing of applications
d.    Frequency of applications
e.   Level of effectiveness
f.   Topical vs. systemic
h.   Toxicity and hazards
I.   Equipment necessary
1.2.0  Bacterial pathogenic diseases
1.2.1  Symptoms of damage to plants
a.   Leaf spots
b.   Galls on stems
c. T  wig and stem die back
d.   Gall on crowns
1.2.2  Conditions favorable for bacterial development
a.   Moisture and humidity levels
b.   Temperature range
1.2.3   Susceptibility of host plants
a.   Highly susceptible
b.   Moderate acceptability
c.   Resistant
1.2.4  Availability and location of bacteria
a.   Dormant stage
b.   Active stage
c.   Internal damage
d.   Exterior damage
1.2.5  Period of activity
a.   Season of the year
1.2.6  Damage to specific hosts
a.   Plants known to be damaged
b.   Specific symptom related to a specific host
1.2.7  Control measures
a.   Removal
b.   Pruning
c.   Bactericides
1.2.8  Bactericides
a.   Effectiveness
b.   Timing of applications
1.3.0  Viral diseases
1.3.1  Location of viral disease
a.   Inside plant tissue and vascular systems
1.3.2  Symptoms of virus
a.   Mosaic
b.   Yellowing
c.   Stunting
1.3.3 conditions favorable for virus development
a.   Active growth stage of plants
b.   Food sources
c.   Temperature and moisture requirements
1.3.4  Susceptibility of host plants
a.   Specific plants effected by virus
b.   Virus resistance of hosts
1.3.5  Control measures
a.   Removal
b.   Prevention
2.0  Identification of insects
2.1.0  Insects with a complete life cycle
2.1.1  Season of adult stage
2.1.2  Season of larval stage
2.1.3  Damage by larvae
2.1.4  Damage by adult
2.1.5  Specific Insects
a.   Hosts damaged
b.   Specific symptom of damage
2.1.6  Control measures
a.  Timing of controls
b.   Specific insecticides effective
c.   Predator and beneficial insect considerations
d.   Health of host plants
2.1.7  Location of insect damage
a.   Leaves
b.   Stems and trunk
c.   Roots
2.2.0  Insects with an incomplete life cycle
2.2.1  Season of damage
2.2.2  Specific symptom of damage
2.2.3  Reproductive period
2.2.4  Specific host plants
2.2.5  Location of damage to plants
a.   Leaves
b.   Stems and trunk
c.   Roots
2.2.6  Identification of nymph and adult stage
a.   Size and color change
b.   Absence or presence of wings
2.2.7  Control measures
a.   Timing of controls
b.   Predator and beneficial insect considerations
c.   Health of host plants
I.   Insecticides
2.2.8  Insecticides
a.   Botanical
b.   Microbial
c.   Growth regulator
d.   Nerve inhibitors
c.   Misc. Insecticides
2.3.0  Vector control
2.3.1  Insects ability to spread diseases
a.   Infected mouth parts with bacteria, fungus and virus.
2.4.0  Feeding patterns
2.4.1  Chewing mouth-parts
2.4.2  Sucking mouth-parts
2.5.0  Mite Identification
2.5.1  Reproductive cycle
2.5.2  Symptoms of damage
2.6.0  Mite control
2.6.1  Timing of applications
2.6.2  Miticides
2.6.3  Predator mites
2.6.4  Dormant sprays
3.0  Identification of weeds
3.1.0  Life cycles
3.1.1  Perennial weeds
3.1.2  Biennial weeds
3.1.3  Winter annual weeds
3.1.4  Summer annual weeds
a.   Dicot weeds
b.   Monocot weeds
c.   Noxious weeds in turf
d.   Noxious weeds in nursery stock
3.2.0  Common names of weeds
3.2.1  Weed Science Society of America names
3.3.0  Growth habits
3.3.1  Rosette
3.3.2  Rhizomes
3.3.3  Stolons
3.3.4  Shape
a.   Creeping or spreading
b.   Taller than wide
c.   Oval
3.3.5  Height and width
3.4.0  Description of foliage
3.4. 1 Alternate or opposite
3.4.2  Size and shape of leaves
3.4.3  Gloss or pubescence
3.4.4  Color
3.4.5  Leaf margin
a.   Entire
b.   Serrated
c.   Lobed
d.   Dissected
e.   Wavy
3.5.0  Stem description
3.5.1  Round or square
3.5.2  Color
3.5.3  Rooting at nodes or not rooting
3.5.4  Spacing of nodes
3.6.0  Flower description
3.6.1  Time of bloom
3.6.2  Bloom on terminal stems or at leaf axis
3.6.3  Size of flowers
3.6.4  Double or single
3.6.5  Number of petals
3.6.6   Color and shape of petals
3.7.0  Description of seed characteristics
3.7.1  Seed capsule
a.   Size, shape and color
3.7.2  Seed coverings
a.   Color
b.  Pubescence for wind distribution
c.   Bristles
d.   Flesh description
4.0  Weed control
4.1.0  Cultivation and hand control
4.1.1  Timing and interval of removal
4.2.0  Prevention of weeds
4.2.1  Removal before seeds are produced
4.2.2  Benefits of mulch
4.3.0  Herbicide controls
4.3.1  Pre-emergent herbicides
4.3.2  Post-emergent herbicides
4.3.3  Selective herbicides
4.3.4  Non-selective herbicides
4.3.5 Specific herbicide to control specific weeds
4.3.6  Hazards of herbicide use
4.3.7  Insect predators