Observation

Many candidates avoided question 4.

(a)  This could be due to poor understanding of the taungya system of farming. 

Many candidates who attempted Question 4(a) were unable to identify the agroforestry system as well as its advantages.
(b)  Most candidates were unable to satisfactorily explain the methods of vegetative propagation; thus losing marks.
(c)  Many candidates do not understand the reason why farmers prefer to raise chickens than turkeys in West Africa.

The expected answers include:

4.   (a)  (i)   Type of agroforestry practised by the farmer
-   Taungya system                                                                                              
(ii)  Advantages of taungya system
-   Provides income for the farmer
-   Collection of dry wood for fuel/sale
-   Suppressing of weeds
-   Provides employment for the farmer
-   Maximizes the use of land
-   Improves soil fertility
-   Makes land available for cultivation especially where land is scarce
-   The young trees receive direct and indirect attention from the farmer
-   Increases food production
-   Promotes sustainable environment/erosion control/prevention of desert encroachment

      (b)         Explanation of methods of vegetative propagation

                   (i)     Layering
-      Layering refers to a method of propagating a plant in which a shoot is fastened  
down to the ground to form roots while still attached to the parent plant
-      The shoot is then cut off from the parent plant and transplanted to produce a new
plant
-      Methods of layering include aerial/air layering, ground layering

(ii)   Cutting
-      Cutting involves the taking of a suitable part of a plant with nodes and placing it                   
in the soil for it to grow

•  Cutting can be prepared from stems, roots and leaves of plants for planting     

                                                                                 
(iii)  Grafting

•      Grafting involves joining the shoot (scion) of one plant with the rootstock of another plant of the same species

•  The shoot should be of the same size as that of the rootstock
•   Methods of grafting include tongue, splice, cleft and approach grafting                                                                                   

            (c)        Reasons why farmers in West Africa prefer to raise chickens than turkeys
-   Short production period/grow faster
-   Chicken eggs are in high demand than turkey eggs
-   Chicken meat is more affordable to consumers than turkey meat
-   The floor space required by chickens is less, thus more chickens can be raised per square meter than turkeys
-   Chickens can be raised in battery cages more conveniently than turkeys
-   Chickens are cheaper to raise than turkeys
-   Chickens require less more attention and energy to raise than turkeys                            

                                                                     
(d)       Methods of controlling weeds
-   Physical/mechanical weed control e.g. ploughing, slashing
-   Chemical control methods through the use of herbicides
-   Biological control method e.g. cover cropping
-   Cultural methods e.g. crop rotation, burning, flooding