Agricultural Science Paper 2, Nov/Dec 2010  
Questions: 1 2 3 4 5 6 7 8 9 10 Main
General Comments

Question 6

(a) State four advantages of grafting. [ 4 marks]
(b) Mention four ways by which forests enhance soil conservation. [ 4 marks]
(c) State two forestry regulations in your country. [ 2 marks]
(d) In an afforestation programme, teak seedlings were planted at 4m x 4m. After transplanting, 10.5% of the seedlings were lost to stress. Before harvesting, additional 12.8% were lost to wind damage. Calculate:

(i) the number of teak seedlings required to plant 2.3 hectares of farm land; [ 2 marks]
(ii) the number of teak seedlings lost to stress; [ 2 marks]
(iii) the number of teak stands harvested. [ 2 marks]


Few candidates attempted this question and their performance was below average. In question 6(a), most of the candidates could not state the advantages of grafting. However, many candidates were able to mention the ways by which forests enhance soil conservation as required in question 6(b).

In question 6(c), most of the candidates were unable to state the forestry regulations in therir country. Also, in question 6(d), many candidates could not calculate the number of teak seedlings from the information provided.

The expected answers include:

Advantages of grafting
- Plants that produce very few or no seeds can be propagated e.g. navel orange
- Plants mature and bear fruits early
- The quality of one plant can be blended with the quality of another plant
- Seed dormancy problems are completely eliminated
- Plant sizes that make harvesting and other operations easier can be produced
- Pollination agents are not required
- The hazards of fertilization are avoided

Forestry Regulations:
- Prohibition of individuals or group of persons from entering forest reserves to hunt, to fell
- forest trees or farming without permission
- Prohibition of persons from setting fire on forest reserves
- Prohibition of indiscriminate exploitation of forest trees

Number of teak seedlings required to plant 2.3 hectares of farm land
1 plant occupies 4m x 4m
       = 16m
10,000m2 = 1 hectare
•• l0,000m2
= 625 seedlings/hectare
       2.3 hectare will need
       625 x 2.3
    = 1437.5 plants
    ~ 1,438 seedlings

Number of Seedlings lost to stress
10.5% of the seedlings were lost to stress during transplanting
.'. 10.5 x 1,438 seedlings
= 150.94 plants
~ 151 seedlings
% of trees lost to wind damage
= 1,438 - 151 = 1287

= 12.8 x 1287
= 164.736
≈ 165 seedlings

No. oftrees harvested: = 1438 -151-165 = 1,122 teak stands.


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