WAEC SSCE - Agricultural Science - 2017 (Practical)

The specimens are identified in the question: I (wheelbarrow), J (file), K (palm oil) and L (cotton lint).

(a)(i) Two uses each of specimens I and J:

Specimen I (wheelbarrow):

• For carrying/conveying farm inputs such as manure, seeds and tools.
• For conveying harvested produce and farm refuse within the farm.

Specimen J (file):

• For sharpening the cutting edges of tools such as cutlasses and hoes.
• For smoothing/removing rough edges from metal and wood.

(a)(ii) Two general ways of maintaining specimens I and J:

• Clean them after use and store them in a dry shed to prevent rust.
• Oil/grease the metal parts (and the wheel of the wheelbarrow) and repair or replace worn parts.

(b)(i) Botanical names of the crops:

• Specimen K (palm oil) is obtained from the oil palm, Elaeis guineensis.
• Specimen L (cotton lint) is obtained from cotton, Gossypium hirsutum.

(b)(ii) Steps in the traditional method of producing palm oil (specimen K):

1. Harvest ripe oil-palm fruit bunches and allow them to ferment for a few days.
2. Strip/detach the fruits from the bunches.
3. Boil the fruits in water to soften the mesocarp.
4. Pound the boiled fruits in a mortar (or trample) to separate the fibre, nuts and pulp.
5. Mix with water and squeeze/knead so the oil floats to the surface.
6. Skim off the floating oil and boil it again to remove water, then allow to cool and store.

(a) Specimen E (NPK 15:15:15):

• (i) Three major nutrients supplied to crops: Nitrogen (N), Phosphorus (P) and Potassium (K).
• (ii) Three methods of applying specimen E on a farm:
  • Broadcasting (spreading evenly over the field).
  • Band placement/side dressing (placing beside the rows or plants).
  • Ring/spot application (placing around each plant).

(b) Three agricultural uses of each of specimens F and G:

Specimen F (wood ash):

• Used to supply potassium (potash) to the soil.
• Used to reduce soil acidity (as a liming material).
• Used to control storage pests of grains and legumes.

Specimen G (limestone):

• Used to reduce soil acidity (raise soil pH) - liming.
• Supplies calcium and magnesium to the soil.
• Improves soil structure and the activity of soil micro-organisms.

(c) Three ways in which specimen H (cow dung) is important to the soil:

• It adds plant nutrients and improves soil fertility.
• It increases the organic matter/humus content and improves soil structure.
• It improves the water-holding capacity and aeration of the soil and feeds soil organisms.

The specimens are identified in the question: P (aphid), Q (cowpea seeds) and R (coconut fruit).

(a)(i) Three effects of specimen P (aphid) on crops:

• It sucks plant sap, causing wilting, yellowing and stunted growth.
• It transmits viral diseases from plant to plant.
• Its sugary excreta (honeydew) encourages sooty mould, which reduces photosynthesis and yield.

(a)(ii) Two ways of controlling specimen P (aphid):

• Spray with an appropriate insecticide (contact/systemic).
• Encourage/use natural enemies such as ladybird beetles (biological control) and plant resistant varieties.

(b)(i) Two benefits of including the crop from which specimen Q (cowpea, a legume) was obtained in a mixed cropping system:

• It fixes atmospheric nitrogen through its root nodules and enriches the soil.
• It provides ground cover that reduces soil erosion and weed growth, and gives extra food/income.

(b)(ii) Major storage pest of specimen Q (cowpea): The cowpea weevil / bruchid, Callosobruchus maculatus.

(c) Five uses of specimen R (coconut):

• The white kernel is eaten as food.
• The coconut water is a refreshing drink.
• Oil is extracted from the kernel for cooking, soap and cosmetics.
• The husk (coir) is used to make ropes, mats and brushes.
• The hard shell is used for making cups, ladles, charcoal and ornaments.

(d) Botanical names:

• Specimen Q (cowpea): Vigna unguiculata.
• Specimen R (coconut): Cocos nucifera.

The specimens are identified in the question: T (chicken egg) and U (tilapia fish).

(a)(i) Three breeds of the farm animal (domestic fowl) that produces specimen T:

• White Leghorn
• Rhode Island Red
• Plymouth Rock (or Sussex)

(a)(ii) Four ways in which specimen T (egg) is economically important:

• It is a rich source of animal protein in human diet.
• It is sold to earn income for the farmer.
• It is hatched to produce chicks and increase the flock.
• It is used as raw material in industry (for making vaccines, confectioneries and cosmetics).

(b)(i) Two methods of harvesting specimen U (tilapia) from the pond:

• By using nets (seine/cast/drag nets).
• By draining the pond and hand-picking the fish (or by using hooks/traps).

(b)(ii) Two by-products from processing specimen U:

• Fish meal (from waste and offal, used in animal feed).
• Fish oil (and fish manure/skin).

(b)(iii) Four methods of preserving specimen U (fish):

• Smoking
• Sun-drying
• Salting
• Freezing/refrigeration (or canning)