1. Define or explain the following terms used in plant protection with examples.
i. Systemic insecticide.
[2]
ii. Post-emergence herbicide application.
[2]
2. Briefly, explain the impact of plant pests to the horticultural sector in Namibia.
[S]
3 a. Name a plant disease of your choice and explain the aetiology and epidemiology of the
disease and recommend appropriate recommended control measures.
[20]
b. Explain the importance of epidemiology in disease management?
[4]
4. Using your own examples of pest/ disease and crop; explain how crop rotation can be
used to control pest and plant diseases.
[10]
5. a. Name four (3) advantages of using biological pest control methods.
[2]
b. List three (3) precautions to keep in mind when using chemical control measures. [3]
6. Tomato spotted wilt (caused by tomato spotted wilt virus) is generally considered a
monocyclic disease of tomatoes. Explain what this means.
[2]
7. Damping off is a disease that affects seedlings in the nursery.
a. Describe the symptoms of damping-off on seedlings and factors favouring its
development.
[4]
b. Describe the integrated pest management of damping off in the nursery seed bed.
[4]
8. a. What are three ways that a plant virus can be transmitted from one plant to another
in a field?
[3]
b. Why is management of plant viral diseases always based on prevention, rather than
curing?
[2]
c. A potato grower in Tsumeb sprayed his virus infected potato plants with a pesticide.
Is the use of pesticide to manage viruses in the field a correct procedure? Yes or No.
Justify your answer.
[2]
Suggest to the farmer any three strategies that he can use to prevent future outbreak
of viral diseases in his potato field.
[3]
9. a. Explain why weeds are a problem in conservation agricultural systems? Explain in
detail how you would address the problem.
[6]
b. Weeds can be controlled by mechanical and biological methods. For each of these
methods, describe the advantages and disadvantages of each .
[8]
2