PCA EXAM
Answer PLANT PATHOGENS
1. Plant disease
Answer Abnormal physiological processes caused by a causal pathogen
2. What is the economical significance of plant disease
Answer Losses of yields, crops, inputs, and land
3. Pathogen
Answer a causal agent of the disease
4. Disease
Answer an abnormal condition that causes issues like declined health or death of a plant
5. Sign
Answer the presence of a structure of a pathogen (spore, mycelium, or even mold growth)
,6. Symptom
Answer a plant response to a pathogen infection (decline of growth, vigor, or even death)
7. What are some abiotic factors that cause plant diseases
Answer
8. What are some biotic factors that cause plant diseases
Answer
9. Obligate parasite
Answer Unable to grow outside of a living host (viruses)
10. Facultative saprophytes
Answer prefers living organic matter as a source of nutrition but can adapt to the use of dead organic matter
under certain conditions (phytophthora)
11. Facultative parasites
,Answer a pathogen that prefers dead inorganic material, but can also obtain nourishment from living organic
material (bacteria)
12. Biotrophic
Answer Any parasite that cannot survive in a dead host and therefore keeps it alive
13. Necrotrophic
Answer parasites that kill the host cells
14. Kotch postulates
Answer A series or guidelines used to identify the microorganism that causes a specific disease
15. What are the three components of plant disease triangle
Answer the environment, the host, and the causal agent
16. What is the role of each of the component of the disease triangle
Answer All three must be present in order for infection to take place, the environment must favor the causal
, agent and the host must be susceptible to the causal agent
17. How do humans impact the disease triangle
Answer Humans can manipulate the environment, plant
host resistant varieties, and use preventative/suppressive/eradicative pesticides all to change a piece of the disease
triangle
18. How does one component of the triangle impact a epidemic if it does not
come into contact with the other two
Answer If one component of the plant disease triangle is missing the epidemic will slow to a halt, in order
for the disease to spread it must have all three parts of the triangle
19. How can you break the environment portion of the disease triangle
Answer alter planting dates, remove alternative host, alter harvest dates
20. How can you break the host portion of the disease triangle
Answer PLANT PATHOGENS
1. Plant disease
Answer Abnormal physiological processes caused by a causal pathogen
2. What is the economical significance of plant disease
Answer Losses of yields, crops, inputs, and land
3. Pathogen
Answer a causal agent of the disease
4. Disease
Answer an abnormal condition that causes issues like declined health or death of a plant
5. Sign
Answer the presence of a structure of a pathogen (spore, mycelium, or even mold growth)
,6. Symptom
Answer a plant response to a pathogen infection (decline of growth, vigor, or even death)
7. What are some abiotic factors that cause plant diseases
Answer
8. What are some biotic factors that cause plant diseases
Answer
9. Obligate parasite
Answer Unable to grow outside of a living host (viruses)
10. Facultative saprophytes
Answer prefers living organic matter as a source of nutrition but can adapt to the use of dead organic matter
under certain conditions (phytophthora)
11. Facultative parasites
,Answer a pathogen that prefers dead inorganic material, but can also obtain nourishment from living organic
material (bacteria)
12. Biotrophic
Answer Any parasite that cannot survive in a dead host and therefore keeps it alive
13. Necrotrophic
Answer parasites that kill the host cells
14. Kotch postulates
Answer A series or guidelines used to identify the microorganism that causes a specific disease
15. What are the three components of plant disease triangle
Answer the environment, the host, and the causal agent
16. What is the role of each of the component of the disease triangle
Answer All three must be present in order for infection to take place, the environment must favor the causal
, agent and the host must be susceptible to the causal agent
17. How do humans impact the disease triangle
Answer Humans can manipulate the environment, plant
host resistant varieties, and use preventative/suppressive/eradicative pesticides all to change a piece of the disease
triangle
18. How does one component of the triangle impact a epidemic if it does not
come into contact with the other two
Answer If one component of the plant disease triangle is missing the epidemic will slow to a halt, in order
for the disease to spread it must have all three parts of the triangle
19. How can you break the environment portion of the disease triangle
Answer alter planting dates, remove alternative host, alter harvest dates
20. How can you break the host portion of the disease triangle
