Plant Disease Final

Question 1

What are soil inhabitants?

Answer 1

An organism that maintains its population in soil for an extended period of time

Question 2

What are soil invaders?

Answer 2

An organism who’s population diminishes the soil over a period of time

Question 3

What is an epiphyte?

Answer 3

An organism growing on the plant surface, not as a parasite

Question 4

What are the longest times a plant pathogen can survive in plant debris or soil?

Answer 4

Fusarium Wilt; 30 Years
Verticillium Wilt
TMV Tomato Mosaic Virus

Question 5

What is the purpose of quantifying degree days?

Answer 5

Aids in pest mgmt; time when the plant will be mature so it has more resistance to the pest/less pest pressure

Question 6

What is pectin & pectinase?

Answer 6

Pectin essentially glues cell walls together
Pectinase breaks down pectin; breaks down development in fungi

Question 7

What is an incubation period?

Answer 7

The time between penetration from the host & the first appearance of symptoms

Question 8

What is a latent period?

Answer 8

The time between infection & production of new inoculum
The time after a vector has acquired a host before it can be transmitted

Question 9

What is a structural plant defense?

Answer 9

Thorns

Question 10

What is a chemical plant defense?

Answer 10

Sap to clog pests

Question 11

What is a passive or constitutive plant defense?

Answer 11

Physical barriers such as waxy leaves or thick bark

Question 12

What is an active or induced plant defense?

Answer 12

Produced in response to a stimulus
Toxic chemical production, deliberate cell death etc
Uses a lot of energy

Question 13

What is SAR (Systemic Acquired Resistance)?

Answer 13

Resistance covering plant
A rapid & coordinated response against a variety of pathogens as a signal travels throughout the plant
Induced by pathogen killing cells or producing chemicals
Signal is then sent to turn on defenses

Question 14

What are the different host plant reactions to pathogens?

Answer 14

Resistant- Doesn’t Affect
Tolerant- Affects but won’t kill
Susceptible- Will damage the most & possibly kill

Question 15

What is an elicitor?

Answer 15

A molecule produced by host or pathogen that induce a response from host or pathogen
Monomers & Oligomers can be elicitors for plant reactions

Question 16

What is a receptor?

Answer 16

A site that binds & recognizes elicitor
Any organ that is sensitive to a specific molecule

Question 17

What is vertifolia effect?

Answer 17

Essentially loss of resistance when R genes are introduced to cultivars

Question 18

What is the benefit of a plant having a more general resistance vs a specific R gene?

Answer 18

You’ll get more resistance

Question 19

What does transgenic mean?

Answer 19

Possessing a gene from another species
Describes organisms that have been subject to genetic engineering

Question 20

What does GMO mean?

Answer 20

Genetically Modified Organism
Genetic makeup has been altered using genetic engineering techniques

Question 21

What is an infection period?

Answer 21

Time needed for infection to occur under proper the environment
Hours of leaf wetness & temperature for foliar pathogens

Question 22

What are some possible effects of plant disease epidemics on people?

Answer 22

Can hurt economically
Loss of crops
No fruiting therefore no fruit
No ornamentals

Question 23

What is a mycotoxin?

Answer 23

Given off from a fungus

Question 24

What are 3 sources of pathogen transmission to a host plant?

Answer 24

Vectors (Pests)
Mechanical (h2o splashing, soil uptake)
Wounds

Question 25

What is a polycyclic pathogen?

Answer 25

Having many disease cycles in a growing season
Air or vectorborne

Question 26

What is a monocyclic pathogen?

Answer 26

Only having one disease cycle within the growing season
Soilborne pathogens

Question 27

What are four cultural practices utilized to help eradicate pathogens?

Answer 27

Sanitation
Scouting
Solarization; Heat treatment
Parasitism
Chemicals

Question 28

What is hyperparasitism as a biological control?

Answer 28

A parasite that is parasitic to another parasite

Question 29

What is predation as a mean to a biological control?

Answer 29

Introduce an insect that will eat the pest; won’t lay eggs inside it or depend off the bug but will kill it

Question 30

What are 4 cultural practices used for plant protection?

Answer 30

Prevention
Good Temperatures
Physical barriers
H2o management

Question 31

What are 5 methods of reducing leaf wetness?

Answer 31

Water soil surface
Fans
Spacing
Orientation
Shade Reduction

Question 32

What does LD50 of a pesticide measure?

Answer 32

The lethal dose to 50% of the population

Question 33

What is a contact or protectant fungicide?

Answer 33

Must make contact or touch pest to break down exoskeleton

Question 34

What is a systemic or penetrant fungicide?

Answer 34

Can be uptaken by roots & pests will die from ingesting it

Question 35

How do you reduce fungicide resistance?

Answer 35

Rotate fungicides daily; use different chemicals

Question 36

What are advantages to genetic resistance of plants to pathogens?

Answer 36

Don’t have to treat for pests at all as they can do it themselves

Question 37

What is the theory behind planting a multiline mixture of a crop even though it is all the same species?

Answer 37

Reducing the spread by keeping it on that one species only

Question 38

What is gene pyramiding?

Answer 38

Introducing multiple genes for resistance
Multiple R genes present in single cultivar

Question 39

What is the purpose of having plant quarantines?

Answer 39

To stop spread to other plants, Stop invasive species + spread of diease by keeping plants from other countries out

Question 40

What is an epidemic?

Answer 40

Increase of plant diseases over time

Question 41

What is an obligate parasite example?

Answer 41

Biotroph

Question 42

What is a facultative pathogen example?

Answer 42

Epiphytes

Question 43

Protoplast fusion

Answer 43

Create genetic variation for selection