PCA - PLANT PATHOGENS
1. Plant Disease Definition
Answer Abnormal physiological processes caused by a causal pathogen
2. Economic significance of plant diseases
Answer Losses of yield, crops, inputs, land
3. Pathogen
Answer Causal agent of disease
4. Signs of disease
Answer Structures of the pathogen
5. Symptoms of disease
Answer Plant response to pathogen infection
6. Abiotic factors of plant disease
Answer Air pollution, temperature, nutrients
7. Biotic factors of plant disease
, Answer Living organisms (fungi, bacteria, viruses)
8. Obligate parasite
Answer unable to grow outside of a living host
9. Facultative saprophyte
Answer prefers living organic matter as a source of nutrition but can adapt to the use of dead organic matter
under certain conditions
10. Facultative parasite
Answer A pathogen that prefers dead inorganic material, but can also obtain nourishment from living
organic material
11. Biotroph
Answer Any parasite that cannot survive in a dead host and therefore keeps it alive
12. Necrotroph
Answer Parasite that kills host cells
13. Koch's Postulates
Answer series of guidelines used to identify the microorganism that causes a specific disease
,14. Three components of disease triangle
Answer Causal agent, environment, host
15. Role of each component of disease triangle
Answer All three must be present for disease to occur. Environment must favor causal agent. Host must
favor causal agent.
16. How humans impact each component of disease triangle
Answer Manipulate the environ- ment, host-plant resistance, preventative/suppressive/erradicative
pesticides
17. Impact of epidemic when one component of disease triangle does not come
into contact with the other two componentsAnswer Slows epidemic to a halt. Disease spread
needs all three components interacting
18. Management strategy to break environment component
Answer Alter planting dates, remove alternative hosts, alter harvest
19. Management strategy to break host componentAnswer Alternate crop, host-plant
resistance
, 20. Management strategy to break causal agent component
Answer Pesticide applications
21. How can knowledge of plant disease triangle be used in diagnosis?
Answer Can rule out ditterent pathogens based on host and environment.
22. Epidemiology
Answer Branch of medical science concerned with the incidence, distribution, and control of diseases that attect
large numbers of people.
1. Plant Disease Definition
Answer Abnormal physiological processes caused by a causal pathogen
2. Economic significance of plant diseases
Answer Losses of yield, crops, inputs, land
3. Pathogen
Answer Causal agent of disease
4. Signs of disease
Answer Structures of the pathogen
5. Symptoms of disease
Answer Plant response to pathogen infection
6. Abiotic factors of plant disease
Answer Air pollution, temperature, nutrients
7. Biotic factors of plant disease
, Answer Living organisms (fungi, bacteria, viruses)
8. Obligate parasite
Answer unable to grow outside of a living host
9. Facultative saprophyte
Answer prefers living organic matter as a source of nutrition but can adapt to the use of dead organic matter
under certain conditions
10. Facultative parasite
Answer A pathogen that prefers dead inorganic material, but can also obtain nourishment from living
organic material
11. Biotroph
Answer Any parasite that cannot survive in a dead host and therefore keeps it alive
12. Necrotroph
Answer Parasite that kills host cells
13. Koch's Postulates
Answer series of guidelines used to identify the microorganism that causes a specific disease
,14. Three components of disease triangle
Answer Causal agent, environment, host
15. Role of each component of disease triangle
Answer All three must be present for disease to occur. Environment must favor causal agent. Host must
favor causal agent.
16. How humans impact each component of disease triangle
Answer Manipulate the environ- ment, host-plant resistance, preventative/suppressive/erradicative
pesticides
17. Impact of epidemic when one component of disease triangle does not come
into contact with the other two componentsAnswer Slows epidemic to a halt. Disease spread
needs all three components interacting
18. Management strategy to break environment component
Answer Alter planting dates, remove alternative hosts, alter harvest
19. Management strategy to break host componentAnswer Alternate crop, host-plant
resistance
, 20. Management strategy to break causal agent component
Answer Pesticide applications
21. How can knowledge of plant disease triangle be used in diagnosis?
Answer Can rule out ditterent pathogens based on host and environment.
22. Epidemiology
Answer Branch of medical science concerned with the incidence, distribution, and control of diseases that attect
large numbers of people.
