JAMB Agricultural Science Past Questions & Answers - Page 31

The primary role is the production of food ,all other roles/functions are secondary. 

At III law of Diminishing returns sets in.

Diminishing returns, also called law of diminishing returns or principle of diminishing marginal productivity, economic law stating that if one input in the production of a commodity is increased while all other inputs are held fixed, a point will eventually be reached at which additions of the input yield progressively smaller, or diminishing, increases in output.

The tree in this question is a rubber tree and the process depicted is rubber tapping. Rubber tapping is the process by which latex is collected from a rubber tree. The latex is harvested by slicing a groove into the bark of the tree at a depth of one-quarter inch with a hooked knife and peeling back the bark

The picture shown above is a bidding knife .A budding knife is a small knife with a type of spatula at the other end of the handle.

Budding, often called bud grafting, is an artificial method of asexual or vegetative propagation in plants. Like grafting, this method is employed to convert one plant (the rootstock) into another plant type with desirable characteristics. Similarly, the resultingplants. s

Hevea brasiliensis, the Pará rubber tree, sharinga tree, seringueira, or, most commonly, the rubber tree or rubber plant, is a flowering plant belonging to the spurge family Euphorbiaceae. It is the most economically important member of the genus Hevea because the milky latex extracted from the tree is the primary source of natural rubber.