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 2008
 Questions: 1 2 3 4 Main
Weakness/Remedies
Strength

Question 2

The diagrams below illustrate different forms of storage structures for agricultural produce.  Use them to answer questions (a), (b), (c), (d), (e) and (f).

(a) Identify the forms of storage structures illustrated by the diagrams: I, II, III, IV and V.                                                                                                                               (5 marks)
(b) State two advantages of using storage structure II over storage structure I.                                                                                                                        (2 marks)
(c) Briefly describe how you would  construct the storage structure illustrated
by diagram III.                                                                                         (2 marks)
(d) State two precautions that must be taken when using each of the storage structures
labeled III and IV.                                                                                               (2 marks)
(e) Which of the storage structures is most suitable for the following activities?
(i)Commercial storage of cereal crops.                                              (1 mark)
(ii) Preservation of fish.                                                                       (1 mark)

(f)  List four materials used in the construction of storage structure V.      (2 marks)

_____________________________________________________________________________________________________
OBSERVATION

This question was fairly attempted by the candidates.  In 2(a), many candidates could identify storage structures II (silo) and III (barn), while most of the candidates could not identify storage structures I (crib), IV (rafter) and V (rhumbus).

Also, in 2(b), many candidates could not state the advantages of using storage structure II (silo) over storage structure I (crib).  In 2(c), majority of the candidates were unable to describe how to construct storage structure III (Barn).  While in 2(d), some candidates could not state the precautions that must be taken when using storage structures III (barn) and IV (rafter).

However, in 2(e), majority of the candidates could name the storage structures that are most suitable for commercial storage of cereal crops and preservation of fish.  Also, in 2(f), most candidates could list the materials used in the construction of storage structure V (rhumbus).

Forms of storage structures illustrated by diagrams:

I:          Crib
II:         Silo
III:        Barn
IV:       Rafter/Smoke device
V:         Rhumbus

Advantages of using storage structure II over I

1. Pests cannot attack the stored produce because it is air-tight;

-           Stored produce are protected from inclement weather;
-           Stored grains are protected from rain water because it is water tight;
-           Use of insecticide/pesticide is more effective;
-           Produce stores better and stays longer;
-           Can accommodate large quantity of produce;
-           It can be mechanically operated and is less laborious;
-           Stored produce is better protected against diseases.

How to construct storage structure III

-           Select strong, straight sticks and cut them to the required height to be used as stake;
-           Dig holes at intervals to erect the stakes;
-           Tie the installed stakes across to fortify the stands;
-           Select yam tubers that are free from pest and disease attacks and whose skin is not damaged or bruised;
-           Tie the healthy yam tubers on the stake with the aid of twine or other similar materials and ensure that the yam skin is not damaged or bruised by the twine;
-           Erect canopy over the established barn using palm fronds to protect it from sun and rain;
-           Use wood preservative on the poles while erecting the poles.

Precautions that must be taken when using storage structures III and IV

Structure III

•  The tubers must be kept away from the soil;
• The tubers must not be bruised or damaged;
• The tubers must be protected from direct sun rays;
• The tubers must be protected from the rain;
• There must be space for the easy movement of air;
• Use wood preservative on the poles.

Structure IV

• The smoke must be continuous to prevent pest infestation;
• The heat should not be too much to prevent the killing of the
embryo and  damage to the endosperm.