1. All but one of the following may be used to eliminate Phytophthora from water:
          a.  chlorine
          b.  ozone
          c.  UV light
          d.  fungicides
          e.  filters

2. All but one of the following cultural practices will help control Phytophthora diseases:
          a.  removing sick and dying plants
          b.  raking up and disposing of fallen leaves
          c.  treating plants with fungicides as soon as symptoms are apparent
          d.  eliminating standing water from the production areas
          e.  growing plant species or varieties that are resistant to Phytophthora

True/False Questions

3. The disease triangle consists of 3 factors: a susceptible host, a virulent pathogen, and fungicide management.

4. Phytophthora is a problem in nurseries, but only in the Pacific Northwest.

5. The single most important cultural practice for controlling Phytophthora disease in the nursery is water management.

6. Sanitation makes little difference in the nursery because Phytophthora spores are everywhere.

7. Contact fungicides are best used before the pathogen tries to infect the plant.

8. Systemic fungicides inhibit germination and/or penetration of spores into plant tissues.

9. Reusing pots increases the risk of disease.

10. An effective way to control Phytophthora diseases is to treat plants with fungicides as soon as symptoms become apparent.

 

 

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Answers to Practice Questions

1. All but one of the following may be used to eliminate Phytophthora from water:

          a.  chlorine
          b.  ozone
          c.  UV light
          d. fungicides
          e.  filters

2. All but one of the following cultural practices will help control Phytophthora diseases:
          a.  removing sick and dying plants
          b.  raking up and disposing of fallen leaves
          c. treating plants with fungicides as soon as symptoms are apparent
          d.  eliminating standing water from the production areas
          e.  growing plant species or varieties that are resistant to Phytophthora

True/False Questions

3. The disease triangle consists of 3 factors: a susceptible host, a virulent pathogen, and fungicide management. (False, not fungicide management but suitable environment.)

4. Phytophthora is a problem in nurseries, but only in the Pacific Northwest. (False, Phytophthora is a problem nationwide!)

5. The single most important cultural practice for controlling Phytophthora disease in the nursery is water management. (True)

6. Sanitation makes little difference in the nursery because Phytophthora spores are everywhere. (False, sanitation is helpful at all plant growth stages.)

7. Contact fungicides are best used before the pathogen tries to infect the plant. (True)

8. Systemic fungicides inhibit germination and/or penetration of spores into plant tissues. (False, these fungicides only prevent colonization of plant tissue.)

9. Reusing pots increases the risk of disease. (True)

10. An effective way to control Phytophthora diseases is to treat plants with fungicides as soon as symptoms become apparent. (False, once the plant is infected and showing symptoms of disease, it is too late to begin fungicide applications. Fungicides should only be used only to prevent infections. They do not get rid of symptoms.)