waecE-LEARNING
Home
Technical
Mathematics
Languages
Science
Social Science
Art
Literature Arabic Islamic Studies C.R.KHistory MusicVisual Art Clothing/Textile Home Management Shorthand
 
Agricultural Science Paper 3, Nov/Dec 2010  
Questions: 1 2 3 4   Main
General Comments
Weakness/Remedies
Strength













































Question 3

Study the schematic diagram below carefully and answer the questions that follow.




Step 1 - Step 2 - Step 3 - Step 4 - Step 5 - Step 6 - Step 7 - Step 8 - Step 9 - Step 10

(i) Name the by-product obtained from the process in step 2. [ 1 mark]
(ii) State the use of the named by-product in small ruminants production. [ 1 mark]
(iii) State two uses of the by-product obtained from the process in step 5. [ 2 mark]
(iv) Name the process represented by X which takes place in step 6. [ 2 mark]
(v)State two ways in which the process represented by X is important. [ 2 mark]

(b) A cocoa farmer observed that yields from his cocoa farm were declining. A careful observation revealed that a large number of the mature pods had large discoloured portions. Upon breaking a number of pods he also observed that their internal tissues had brown colouration.

An illustration of an affected cocoa pod is given below.




Study it carefully and answer the questions that follow:

(i) Identify the disease condition on the affected pod. [ 2 marks ]
(ii) Name the possible causal organism of the disease. [ 2 marks ]
(iii) Outline three measures the farmer can take to control the spread of the disease in the farm.
[ 2 marks ]


_____________________________________________________________________________________________________
OBSERVATION

This question was fairly attempted by the candidates. In question 3(a)(i & ii], most of the candidates could name the by-product obtained from the process in step 2 and state the use of the named by-product in small ruminants production.

However, in questions 3(a)(iii - v), many of the candidates were unable to state the uses of the by-product obtained from the process in step 6 nor name the process represented by X which takes place in step 6. likewise, they could not state ways in which the process represented by X is important.

In question 3(b)(i-iii), majority of the candidates could not identify the disease condition on the affected pod, neither could they name the possible causal organism of the disease, nor outline measures the farmer can take to control the spread ofthe disease in the farm.

The expected answers include:

Uses of the by-product obtained from the process in step 6
- Starch for textile industries
- Starch for food/tapioca
- Starch used in laundry work to stiffen clothes
- For drug manufacturing

Name of the process labelled X which takes place in step 6
- Fermentation/fermenting

Ways in which the named process (Fermentation) is important
- Helps to reduce the prussic acids content
- Gives gari a sour taste which makes it more palatable
- Helps to break down the remaining hydrocyanic acid in the pulp

Identification of the disease condition on the pod
- Blackpod disease

Possible causal organism of the disease
- Fungus (Phytophthora palmivora) or
- Phytophthora megakarya)

Measures the farmers can take to control the spread of the disease in the farm
- Removal of all infected pods and burning them
- Weeding regularly
- Spraying pods with recommended fungicides(Perenox, Bordeaux mixture)
- Removal of excess shade
- Early harvesting of ripe pods to prevent infection
- Keep farm clean for good aeration by pruning excess shrubs/ branches
- Plant disease - resistant varieties



 

 

Powered by Sidmach Technologies(Nigeria) Limited .
Copyright © 2012 The West African Examinations Council. All rights reserved.