Final - Section 1 Flashcards
Why do Fungi have two names?
Name for the sexual (teleomorph) form Name for the asexual (anamorph) form
How can tell if the plant problem is due to abiotic or biotic factors?
Biotic – living, irregular patterns
Abiotic – non living, visible patterns
Define Symptom:
Observable condition of the abnormal physiology Affect on host
Define sign:
Physical presence of causal agent
List 4 biotic causal agents:
Fungi Bacteria Nematodes Virus
What is the most important step in diagnosing disease problems?
Send a Plug to the Lab
Define Plant Disease:
a condition of abnormal physiology in a susceptible host plant that is a result of the plants constant association with a disease causing agent within a set of favorable environmental conditions.
List the three groups of abiotic causal agents.
Chemical
Physical
Mechanical
Draw and Label the Plant Disease Triangle
HOST
ENVIRONMENT
PATHOGEN
define predisposition:
Environmental Conditions required by a pathogen to become active (proper temp., moisture, etc.)
define fungistat:
A substance that inhibits the growth of fungi
Define synergism
two or more agents working together to produce a result not obtainable by any of the agents independently
how can fungicide resistance be avoided?
Rotate Mode of Action
define Virulence.
Measure of efficacy
what 3 weeds are good hosts for Scleropthora macrospora?
- Crabgrass
- Quackgrass
- Orchardgrass
name a primary host of Powdery Mildew.
KBG
draw and label 5 fruiting bodies that produce conidia.
.
What are the environmental perameters used to predict Pythium Blight?
Hot Weather
- +85 deg. day & +70 deg. night
Extended Leaf Wetness
- +90% RH for > 10 hours
- poor air circulation
- shade
What are the environmental perameters used to predict Pythium Root Rot?
- Cool to Hot weather
-
Excess Soil Moisture
- Poor Drainage
- Compaction
- Shade
- Poor Air Circulation
What are the environmental perameters used to predict Pythium Root Dysfunction?
-
Root infecions occurs in Fall or Spring
- 50 - 75 deg Soil Temperatures
- Roots dies in summer from heat and drought stress
What is the cause of Stem Rust?
Puccinia graminis
What is the cause of Stripe Rust?
Puccinia striiformis
What is the cause of Crown Rust?
Puccinia coronata
What is Heteroecious Rust?
a rust that has 2 alternate hosts
(Think hetero….2)
What is a Macrocylic Rust?
A rust that has all 5 spore stages
What is a Microcylic Rust?
A rust that has less than 5 spore stages
What is Autecious Rust?
A rust that has only 1 host
Describe the symptom of Rust
Thinning and Yellowing of turf
How do we control Slime Molds?
- Frequent Mowing
- Keep Dry
- Remove Organic Material
What is the crawling stage of a slime mold called?
- Plasmodium
What environmental conditions favor slime molds
- Wet
- Shade
- Thatch
How do slime molds injure turf?
The plasmodium smothers the grass
Where do Smut fungi usually penetrate the plant?
The root cap and grow into the plant from there
What group of Fungi do Smut belong to?
Basidiomycota
Why are penetrant fungicides the only choice for Smut diseases?
Becuase the fungus grows and infects the plant from inside.
What is the main symptom for Smut?
Shredded leaves and thinning turf
In what grass do we usually find Smut?
Poa spp.
What is a good Rust fungicide?
Daconil
Name the spore formed by Smut fungi
teliospore
What animal are slime molds like?
Ameba
