Intro to Plant Pathology

Question 1

What were the 6 purposes of the International Year of Plant Health 2020?

Answer 1

• Keep plants healthy to achieve Zero Hunger and the Sustainable Development goals
• Be careful about bringing plants and plant products across borders
• Make trading in plants and plant products safe by complying with the international plant health standards
• Keep plants healthy while protecting the environment
• Invest in plant health capacity
  development, research and outreach
• Strengthening monitoring and early warning systems to protect plants and plant health

Question 2

What does Phytopathology stand for?

Answer 2

The study of the suffering plant

Question 3

Phyton? Pathos? Logos?

Answer 3

Plant
Suffering
Study

Question 4

Plant Pathology is that branch of what 3 sciences?
What does it deal with?

Answer 4

• Agricultural, botanical and biological sciences
• Deals with the study of:
  –Cause of the disease
  –Resulting losses
  –Control of plant disease

Question 5

What does coffee rust cause?

Answer 5

Premature defoliation

Question 6

What is the result of premature defoliation?

Answer 6

Reduces photosynthesis capacity and weakens the tree

Question 7

Why will coffee rust effect next seasons yield?

Answer 7

Next seasons berries are borne on this seasons shoots, therefore this seasons rust reduces next seasons yields.

Question 8

When and where was the 1st report of Panama disease (TR4 race) in Africa?

Answer 8

April 2013-2014 in Mozambique

Question 9

Is citrus black spot caused by a fungi?

Answer 9

Yes

Question 10

Citrus black spot brings the sa industry to its knees…Why?

Answer 10

Affects export to EU (european union), because europe wants to protect its crops from it

Question 11

What are the affects of citrus black spot on the orange itself

Answer 11

-Reduces quality of the fruit
-Drastically reduces quantity in farming
-Black spot make the fruit look undesireble.

Question 12

Mycotoxigenic fungi is associated with what crops?

Answer 12

Maize and wheat

Question 13

What concerns does Mycotoxigenic fungi present? And for for what/who?

Answer 13

Real food safety and security concerns
For humans and livestock

Question 14

Who are the victims of this “invisible” epidemic ( mycotoxigenic fungi) and from where?

Answer 14

Children in Africa and parts of Asia

Question 15

What are the effects of Mycotoxigenic fungi on children?

Answer 15

Can stunt their growth and delay their development

Question 16

What are the 2 main toxins of Mycotoxigenic fungi?

Answer 16

-Aflatoxin
-Fumosnisin

Question 17

What is plant pathology?
(4)

Answer 17

• Study of the microorganisms and environmental conditions that cause disease in plants

-Mechanisms by which this occurs, (how they cause disease)
- Interactions between the microorganism and the plant (what effects it has on the plant), and
- The methods of managing/ controlling the disease

Question 18

Definition of Etiology

Answer 18

Study of origin, causes (living or non-living) or reasons or disorders in plants.

Question 19

Definition of Pathogenesis

Answer 19

Study of mechanism of disease development i.e. processes of infection and colonization of the host by the pathogen. This phase involves complex host-pathogen interactions

Question 20

Definition of epidemiology

Answer 20

Study the interaction between the causal agent and the diseased plants in relation to environmental conditions. Generally at the population level.

Question 21

Definition of Control/Management

Answer 21

Development of management systems of the diseases land reduction of losses caused by them.

Question 22

What is a disease (Stakman and Harrar 1957)?

Answer 22

Physiological disorder or structural abnormality that is deleterious to the plant or its part or product, that reduces the economic value of the plant

Question 23

Disease

Answer 23

The process in which a pathogen interferes with one or more essential plant cell functions

Question 24

What is a disease (Ward, 1901)

Answer 24

Represents a condition in which functions of the plant are not properly discharged.

Question 25

A disease is a result of?

Answer 25

The intercation between host, pathogens, and environmental

Question 26

What is disease ( British Mycological Society 1950)

Answer 26

Disease is a harmful deviation from normal functioning of physiological processes.

Question 27

Does a disease occur instantly? why?

Answer 27

No, it is a process or a change that occurs over time.

Question 28

What are the 3 elements required for diseases in plants?

Answer 28

- a plant(host) -a pathogen -an environmental

Question 29

The 3 elements that are required for diseases in plants need to be a specific. (plant, pathogen,environment)

Answer 29

- a susceptible plant - a pathogen CAPABLE of causing disease -a favourable environment (for the disease)

Question 30

Susceptibility of plants to diseases are affected by (disease triangle - plant):

Answer 30

Growth stage (age) of the plant * Seedling (young) vs Mature plant (old) Genetic background of the plant * Resistance gene(s) (no disease develop) vs no resistance genes (disease develops) Stress factors * Nutrient and water deficiencies; drought, soil conditions etc

Question 31

What is the definition of pathogen? Pathos? gen? (Disease triangle-Pathogen)

Answer 31

Cause of the disease Suffering origin

Question 32

What are parasites?

Answer 32

Organisms that obtain their nutrients from other living organisms

Question 33

Diseases are caused by parasites such as?

Answer 33

-fungi -Bacteria -Viruses - Nematodes

Question 34

When does parasites become pathogenic?

Answer 34

When they cause harm to harm to the host which results in symptoms (Pathogen)

Question 35

Diseases can be the resulr of biotic or abiotoc. What does both of these mean?

Answer 35

Biotic (Living factors) - Infectious, transmissible Abiotic ( Non-living factors)- Non-infectious, non-transmissible

Question 36

What is required to see bacteria and why?

Answer 36

a microscope because it is extremely small

Question 37

Can the population of bacteria increase in a short time period?

Answer 37

Yes

Question 38

What are colonies (Bacteria)

Answer 38

Cells that clump together in masses

Question 39

How does bacteria spread plant to plant?

Answer 39

BY wind-driven rain

Question 40

How does bacteria infect plants?

Answer 40

Infects through the natural plant openings or injuries.

Question 41

Is the vast majority of fungi beneficial or destructive?

Answer 41

Beneficial

Question 42

For what/who can fungi cause disease

Answer 42

plant, human and livestock

Question 43

Can fungi be seen without a mocroscope

Answer 43

No, most cant be seen without a mocroscope

Question 44

What does fungi lack?

Answer 44

Chlorophyll

Question 45

What is fungi composed of?

Answer 45

Growing structure of deicate, threadlike filaments called hyphae

Question 46

How does fungi reproduce?

Answer 46

BY forming spores

Question 47

What are oomycetes?

Answer 47

Fungi-like structures

Question 48

What are examples of human and animal diseases caused by viruses?

Answer 48

-Influenza -Polio -Rabies Smallpox -Warts

Question 49

What are some destructive things viruses can cause?

Answer 49

Destructive plant diseases

Question 50

Are viruses complete living systems?

Answer 50

No

Question 51

How do viruses survive?

Answer 51

Survive only in living cells

Question 52

How are viruses transmitted and what is it called?

Answer 52

Transmitted by insects and are called vectors

Question 53

(Disease triangle-Environment) What are some climate factors of the environment? (3)

Answer 53

Temperature (extreme highs and lows) Rainfall and irrigation (amount, timing and source) Light intensity

Question 54

What are some soil Characteristics? (3)

Answer 54

Drainage of soils (good or poor) Soil type pH

Question 55

What are examples of moisture and wind in an area?

Answer 55

Ponds and streams Airflow direction

Question 56

What are vectors?

Answer 56

Pathogen spreading organisms

Question 57

What is the definition of a symptom?

Answer 57

a visible or detectable expression of abnormal physiology, development or behavior due to disease

Question 58

What is the definition of a sign?

Answer 58

any observable part of the causal agent (pathogen) in disease

Question 59

What are common signs of plant diseases?

Answer 59

Reproductive structures of pathogens like fungal mycelium and spores

Question 60

What is the difference between a symptom and a sign?

Answer 60

A sign of a plant disease is the PHYSICAL EVIDENCE of the pathogen, such as fungal spores, bacterial ooze, or insect eggs. The actual pathogen) A symptom of a plant disease is the visible EFFECT of the disease on the plant, such as wilting, spots, or yellowing

Question 61

What does a disease cycle represent?

Answer 61

It represents pathogen biology as a series of interconnected stages of development

Question 62

How is the progression through the stages of the plant disease cycle determined?

Answer 62

The progression through these stages is determined by a continuous sequence of interactions among host, pathogen, and environment

Question 63

Diseases can be managed by 4 things and explain each

Answer 63

AVOIDANCE - Selecting a location where the pathogen is not present, or a planting time when the pathogen is not active/cannot grow EXCLUSION - Legal restrictions (quarantine), and the production of pathogen-free seed or plants ERADICATION - Removal of pathogens from infested soil, tools, seed and plant parts PROTECTION - Use of cultural, chemical and biological control, and genetic resistance