Midterm 1

Question 1

Blackleg pathogen

Answer 1

leptospheria maculans - fungi

Question 2

Blackleg hosts

Answer 2

1. canola

2. cabbage, turnip, cauliflower

Question 3

How common is seed infection from blackleg?

Answer 3

not very, but still a concern for international markets

Question 4

resistance and susceptibility to disease (polish & argentine) to blackleg

Answer 4

polish - susceptible

Argentine - moderatley susceptible to resistant

Question 5

asexual or sexual - blackleg

Answer 5

both

Question 6

Disease cycle - blackleg

Answer 6

1. sexual spores are produced on canola trash inside pseudothecia
2. spores are released throughout growing season - airborne (long distance)
3. asexual spores from pycnidia
4. requires splashing in rain
5. short distance

Question 7

Control of blackleg

Answer 7

1. 3-4 year rotation
2. tillage
3. pathogen free seed
4. fungicides - elimination
5. Genetic resistance

Question 8

Signs of white rust

Answer 8

white, powdery pustules

Question 9

symptoms of white rust

Answer 9

stagheads

Question 10

obligate parasitic fungus

Answer 10

must have live host

Question 11

pathogen of verticillium

Answer 11

verticillium longisporum

Question 12

Symptoms of verticillium

Answer 12

black vertical stripes on stems

Question 13

signs of verticillium

Answer 13

microsclerotia inside the stem later in season

Question 14

is sclerotinia sexual or asexual?

Answer 14

sexual

Question 15

non hosts of sclerotinia

Answer 15

corn, cereals

Question 16

signs of sclerotinia

Answer 16

apothecia on ground

sclerotia in stem

Question 17

symptoms sclerotinia

Answer 17

1. stem rot
2. lesions on leaves and stems
3. bleached stems

Question 18

sclerotinia pathogen

Answer 18

sclerotinia sclerotiorum - fungi

Question 19

control of sclerotinia

Answer 19

1. rotation
2. resistance
3. weed control
4. certified seed

Question 20

Biotic agents

Answer 20

living

- fungi, bacteria, viruses, phytoplasma, nematodes, insects

Question 21

Abiotic agents

Answer 21

1. unfavorable weather
2. nutrient deficiencies
3. toxic chemicals and pollutants
4. genetic abnormalities

Question 22

Biotic diseases

Answer 22

1. bacteria
2. fungi
3. viruses
4. nematodes
5. phytoplasma

Question 23

What is a sign?

Answer 23

visable precense of the pathogen

eg. fruiting bodys, mycelia

Question 24

What is a symptom?

Answer 24

physical expression of a change in the appearance and function of a plant

Question 25

pathogen

Answer 25

an agent that causes disease or illness to its host

Question 26

disease development is influenced by:

Answer 26

1. environmental factors 2. rate of pathogen reproduction 3. mode of pathogen dispersal 4. level of pathogen agressiveness 5. level of host plant resistance 6. external intervention - fungicides

Question 27

Disease can be categorized by:

Answer 27

1. Pathogen type 2. symptom type 3. epidemiological progress 4. timing of disease occurrence

Question 28

Fungi

Answer 28

1. multi cellular (eukaryotic) 2. sexual or asexual 3. lack chlorophyll 4. non vascular

Question 29

disease triangle

Answer 29

1. pathogen 2. host 3. favorable environment 4. time

Question 30

nematodes

Answer 30

microscopic worms

Question 31

Phytoplasmas

Answer 31

require vectors - leafhoppers, equipment

Question 32

viruses

Answer 32

dependant on living hosts and vectors (obligate)

Question 33

Bacteria

Answer 33

1. single cellular organisms | 2. multiply rapidly

Question 34

mycelium

Answer 34

vegetative body branches called hyphae

Question 35

Deuteromycetes

Answer 35

Imperfect because they do not seem to have a sexual phase

Question 36

Infection process

Answer 36

1. production of inoculum 2. pre-penetration 3. attachment of pathogen to host 4. recogition between host and pathogen 5. penetration 6. infection

Question 37

Inoculum

Answer 37

Pathogen or its parts capable of causing infection when transferred to a favorable location spores, mycelium, sclerotia etc.

Question 38

Penetration of host

Answer 38

1. direct - fungi, netmatodes 2. through wounds - fungi, bacteria, viruses 3. though natural openings - fungi, bacteria

Question 39

infection

Answer 39

pathogen established contact with susceptible cells/tissues and gets nutrients from them 1. invasion 2. growth and reproduction

Question 40

6 Principles of disease control

Answer 40

1. avoidance 2. exclusion 3. eradication 4. protection 5. resistance 6. therapy

Question 41

Avoidance

Answer 41

1. planting date 2. planting area 3. seed used

Question 42

Exclusion

Answer 42

1. Quarantine 2. Crop certification 3. Chemical treatments

Question 43

Eradication

Answer 43

1. crop rotation 2. removal & destruction of disease 3. heat or chemical treatments 4. soil treatments 5. biological control

Question 44

Protection

Answer 44

chemicals

Question 45

Resistance

Answer 45

heritable trait

Question 46

Therapy

Answer 46

1. heat | 2. chemicals

Question 47

Fungal diseases in potatoes

Answer 47

1. Late Blight 2. Early blight 3. Rhizoctonia black scurf 4. sliver scurf 5. powdery scab 6. verticillium wilt 7. pink rot 8. white mold

Question 48

Bacterial diseases in potatoes

Answer 48

1. blackleg 2. bacterial ring rot 3. scab 4. bacterial wilt

Question 49

Disease control in potatoes

Answer 49

1. sanitation 2. rotation 3. fertility 4. clean seed 5. resistant varieties 6. seed treatments 7. fungicides 8. storage management

Question 50

Clubroot pathogen

Answer 50

Plasmodiophora brassicae

Question 51

Life cycle of clubroot

Answer 51

long living spores (4 year half life)

Question 52

symptoms of clubroot

Answer 52

1. whitish stems 2. decaying galls 3. premature ripening 4. shrivelled seeds 5. wilting, stunting, yellowing

Question 53

Casual agent of clubroot

Answer 53

phytoplasma - not a fungus, not a bacterium

Question 54

Optimal clubroot conditions

Answer 54

1. warm, acid soils

Question 55

Clubroot control

Answer 55

1. resistant hybrids 2. 1:4 rotation 3. control crucifer weeds 4. sanitation 5. 0 till 6. scout 7. biosecurity 8. early ID