Name   __________________________

 

EPWS 310 EXAM 2, Fall 2012

 

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

 

teleomorph

 

 

aseptate (mycelia)

 

 

damping off

 

 

conidia

 

 

cleistothecia

 

 

Zygomycete

 

 

resting spore

 

 

ascospore

 

 

antheridium

 

 

 

2.      (8 pts) Which three classes (ends in -mycete) 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 powdery mildew of roses 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.      (A. (2 pts)  What conditions favor Phytophthora ramorum infection and why?

 

 

B. (3 pts)  In what forms can the pathogen overwinter?

 

 

C.  (3 pts)  In what ways is the pathogen disseminated and how do these influence control

 

 

 

6.     (A. (2 pts)  What are environmental conditions promote Rhizopus soft rot and why? 

 

 

B. (2 pts)  What spore type is most responsible for spread?  ?

 

 

C.  (2 pts)  How can the disease be controlled?

 

 

 

7.      (12 pts) Compare the dissemination methods, primary inoculum, secondary inoculum, overseasoning methods and forms, and control of Phytophthora infestans, which causes late blight of potato and Pythium, which causes damping off.

 

 

 

 

 

 

 

8.     (18 pts) Draw the disease cycle of Plsmopora viticola, which causes downy mildew of grapes, 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.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

9.      (6 pts) A.  What environmental conditions favor Phytophthora capsici root rot of chile and why?

 

 

B.  In what form and where does the pathogen overwinter?

 

 

C.  How can the disease be controlled?

 

 

 

10.  (8pts)  A. What are two ways that you can determine if you are looking at a powdery mildew or a downy mildew?

 

 

B.   How can you microscopically differentiate among the genera of powdery mildew?

 

 

C.  How can you microscopically differentiate among the genera of downy mildew?

 

 

 

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