Principles of Plant Pathology

Question 1

What is Plant Pathology?

Answer 1

The science concerned with Plant Disease

Question 2

What is Plant Disease?

Answer 2

Any deviations from the normal growth of fruit

Question 3

What does Plant Pathology study?

Answer 3

1. Microorganisms and environmental factors that cause disease
2. Mechanisms by which these factors induce disease
3. Methods of disease control

Question 4

What was Plant Pathology associated with since the beginning of agriculture?

Answer 4

Crop failures and famines

Question 5

What are the four types of impacts Plant Diseases have?

Answer 5

1. Famine
2. Economic
3. Agricultural
4. Ecological

Question 6

What was Coffee replaced with because of Coffee Rust?

Answer 6

Tea

Question 7

Is a disease usually one pathogen?

Answer 7

No. Often an interaction of multiple pathogens

Question 8

What causes Potato Early Decline (PED) Syndrome?

Answer 8

Interaction between Verticillium wont and nematodes

Question 9

What are the three factors of Non-Infectious or Abiotic diseases?

Answer 9

1. Physical Factors
2. Pollutants
3. Chemical Factors

Question 10

What are the five Physical Factors of Non-Infectious or Abiotic diseases?

Answer 10

1. Extremes of temperatures (hot or cold)
2. Excess or lack of soil moistures
3. Hail Damage
4. Lightening Damage
5. Implement Damage

Question 11

What are the two types of pollutants associated with Non-Infectious or Abiotic diseases?

Answer 11

1. Air-borne

2. Water-borne

Question 12

What are the three Chemical Factors associated with Non-Infectious or Abiotic diseases?

Answer 12

1. Toxicity of fungicides, insecticides or herbicides
2. Mineral toxicities or deficiencies
3. pH extremes

Question 13

What are the effects of extreme weather conditions?

Answer 13

1. High Temperature causes heat stress on plants or sunburn damage of fruit
2. Frost dampte to vegetables or crops

Question 14

What can cause Iron deficiencies in plants?

Answer 14

High pH soils

Question 15

What happens to nutrient deficient plants? In this case Iron.

Answer 15

• Leaves cannot access enough Iron to make chlorophyll

- Increase in pH locks up the Iron

Question 16

What effects do Nutrient toxicities cause?

Answer 16

• Necrotic lesions
• Cuffing or cupping of leaves
• Chlorosis

Question 17

Is a Non-Infectious or Abiotic disease transmissible or non-transmissible?

Answer 17

Non-Transmissible

Question 18

Is an Infectious or Biotic disease transmissible or non-transmissible?

Answer 18

Transmissable

Question 19

What are the four factors of Infectious or Biotic diseases?

Answer 19

1. Microbial Pathogens
2. Plants
3. Insects, Mites, Nematodes
4. Birds, Mammals

Question 20

What are the Infectious or Biotic Microbial Pathogens?

Answer 20

1. Fingi
2. Bacteria and Mollicutes
3. Viruses and Viroids

Question 21

What are the Infectious or Biotic Plants?

Answer 21

1. Parasitic Higher plants

2. Competitors (Weeds)

Question 22

Where can the symptoms of plant diseases be found?

Answer 22

• Roots
• Leaves
• Seeds
• Flowers

Question 23

What are the four main symptoms of plant disease?

Answer 23

1. Necrosis
2. Wilting
3. Abnormal growth and differentiation
4. Fruit and Foliage Discolouration

Question 24

What is Soft Rot Necrosis?

Answer 24

The tissue rapidly becomes watery and loses coherence

Question 25

What is Dry Rot Necrosis?

Answer 25

Less rapid than a soft rot

Question 26

Are lesions localised or progressive?

Answer 26

Both. Can be localised (leaf spots) or progressive (gradually spreading)

Question 27

How do diseases cause a permanent water deficit in plants?

Answer 27

- Interference with water and nutrient absorption by roots - Interference with water conduction within the plant - Loss of control of transpiration - Infection of roots - Pathogens can get in Xylem Vessels and produce toxins

Question 28

What is associated with the wilting die-back and damping-off of plants?

Answer 28

Diseases that cause a permanent water deficit

Question 29

What does abnormal growth and differentiation cause or affect?

Answer 29

- Affects hormonal balance | - Creates Galls, Nodules, Callus tissue

Question 30

What are the effects of Fruit and Foliage Discolouration?

Answer 30

- Chlorosis | - Anthocyanin

Question 31

What is Chlorosis?

Answer 31

Yellowing due to lack of Chlorophyll

Question 32

What is Anthocyanins?

Answer 32

Red and Purple pigmentation