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PPN610S - PLANT PROTECTION - 2ND OPP - JUNE 2024 |
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n Am I BI A u n IVER s I TY
OF SCIEn CE Ano TECHnOLOGY
FACULTYOF HEALTH,NATURALRESOURCESAND APPLIEDSCIENCES
DEPARTMENT OF AGRICULTURAL SCIENCESAND AGRIBUSINESS
QUALIFICATION: BACHELOR OF SCIENCE IN HORTICULTURE
QUALIFICATION CODE: 07BHOR
LEVEL: 7
COURSE CODE: PPN610S
COURSE NAME: PLANT PROTECTION
DATE: JULY 2024
DURATION: 3 HOURS
PAPER:2
MARKS: 100
SECONDOPPORTUNITY/ SUPPLEMENTARYEXAMINATION QUESTION PAPER
EXAMINER(S) Dr Edgar Mowa
MODERATOR: Dr Grace Kangueehi
INSTRUCTIONS
1. Answer ALL the questions.
2. Write clearly and neatly.
3. Number your answers clearly.
PERMISSIBLEMATERIALS
1. Examination Question paper
2. Examination Answer booklet
3. Calculators
THIS MEMORANDUM CONSISTS OF 4 PAGES (Including this front page)
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SECTION A: SHORT ANSWER QUESTIONS
QUESTION 1:
Defineor explain the following terms used in plant protection with examples.
i. Systemic insecticide
ii. Post-emergence herbicide application
[4 MARKS]
[2]
[2]
Question 2
[S MARKS]
Briefly, explain the impact of plant pests to the horticultural sector in Namibia.
[5]
Question 3
(24 MARKS]
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]
Question 4
[10 MARKS]
Using your own examples of pest/ disease and crop; explain how crop rotation can be used
to control pest and plant diseases.
[10]
Question 5
(5 MARKS]
a. Name four (4) advantages of using biological pest control methods.
[2]
List three (3) precautions to keep in mind when using chemical control measures. [3]
Plant Protection (PPN610S)
2nd Opportunity- July 2024
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Question 6
[2 MARKS]
Tomato spotted wilt (caused by tomato spotted wilt virus) is generally considered a
monocyclic disease of tomatoes. Explain what this means.
[2]
Question 7
[8 MARKS]
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]
Question 8
[10 MARKS]
5. 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]
Question 9
[14 MARKS]
a. Explain why weeds are a problem in conservation agricultural systems? Explain in detail
how you would address the problem.
[6]
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b. Weeds can be controlled by mechanical and biological methods. For each of these
methods, describe the advantages and disadvantages of each.
[8]
Question 10
[4 MARKS]
Tuta absoluta is one of the most destructive pests in Namibia causing yield losses in potato
and tomato production. What will be the disadvantages of using insecticide for controlling
Tuta absoluta on potato.
[4]
Question 11
[10 MARKS]
As a horticulturalist responsible for production of quality tomatoes and potatoes at Mashare
irrigation scheme, you have been using insecticides to control Tuta absoluta in potato fields
for several years, but it's no longer effective. Explain two possible causes of what could have
led to this development and discuss ways you would deal with such a situation.
[10]
Question 12
[4 MARKS]
Mention any of the four strategies that you would use to reduce the primary sources of
inoculum of any pathogen of your choice.
[4]
END OF QUESTIONPAPER
Plant Protection (PPN610S)
2nd Opportunity- July 2024
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