Name   __________________________

 

EPWS 310 EXAM 2, Fall 2008

 

1.     (2 pts each) Define the following terms:

 

plasmodium

 

 

septate (mycelia)

 

 

damping off

 

 

conidia

 

 

karyogamy

 

 

haustorium

 

 

resting spore

 

 

zygospore

 

 

ascogonium

 

 

 

2.      (8 pts) Which three classes of fungi that we discussed in class produce resting spores and zoospores?  What environmental conditions favor diseases caused by these fungi?  What methods can be used to control all these fungi?

 

 

 

 

 

 

 

 

 

3.     (12 pts) Compare the primary inoculum, dissemination mechanism, secondary inoculum, overseasoning place and form, and control of peach leaf curl and club root of crucifers.  (Extra credit 2 pts each, give the genus of the causal agent).

 

 

 

 

 

 

 

 

 

 

4.     (4 pts) List and explain 2 ways that Ascomycetes differ from Zygomycetes.

 

 

 

 

 

 

 

5.     (6 pts) Rhizopus soft rot is a problem primarily in man-made environments.  What environmental conditions that promote the disease, what spore type is most responsible for spread, and how can it be controlled?

 

 

 

 

 

 

 

 

6.     (12 pts) Compare the dissemination methods, primary inoculum, secondary inoculum, overseasoning methods and forms, and control of Phytophthora ramorum, which causes sudden oak death and Pythium, which causes root rots of vegetables.

 

 

 

 

 

 

 

 

 

 

 

7.     (18 pts) Draw the disease cycle of downy mildew, indicating what serves as primary inoculum, secondary inoculum, how it is disseminated, and how it overwinters. Include the sexual gametes and show where plasmogamy, karyogamy, and meiosis occur.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8.      (10 pts) What are three factors that influence damping off?  List two methods of control?

 

 

 

 

 

 

 

9.  (9 pts)  How does the causal agent of late blight of potato overwinter, how is it disseminated if wet, how is it disseminated if dry, and explain control methods to handle all three means.

 

 

 

 

 

 

 

9.     (3 pts)  What are two types of diseases induced by Olpidium, a Chytridiomycete?

 

 

 

 

(6 pts extra credit)   Outline the disease/life cycle of powdery mildew of grape. How can the disease be controlled?