Correct Answer: A. calcium and phosphorus

Explanation

(a) Ways ways By Which Diseases Spread On A Crop Farm: (i) rain splash (ii) use of contaminated tools and equipment. (iii) use of infected planting materials. (iv) wind blowing pathogens to other crops. (v) animals, especially predators during feeding. (vi) insect vectors (vii) visitors (viii) weeds harbour pathogens (ix) through irrigation water.

(b)(i) Symptoms of Onion Twister: (i) Twisting and curling of the leaves and the pseudostem. (ii) The twisted leaves later change from the normal darkgreen colour to yellowish green. (iii) The neck of the affected onion plant becomes abnormally long. (iv) the bulbs are narrow and elongated. (v) The bulbs rot quickly when stored. Control Measures of Onion Twister: (i) Early Planting (ii) Removal and destruction of infected plants. (ill) By spraying fungicides. (iv) Practising good farm sanitation.

(b)(ii) Symptons of Root-Knot Disease of Tomato: (i) Formation of galls or knots on the roots of infected plants. (ii) Stunted plants. (iii) The leaves turn yellow. (iv) Production of many secondary roots. (v) Death of plants. Control Measures of Root-Knot Disease of Tomato: (I) Planting resistant varieties of tomatoes. (ii) Soil treatment with nematicides. (iii) Soil sterilisation/ burning of crop residue and weeds. (iv) Practising crop rotation. (v) Removal of crop residues from the field. (vi) Weed control.

Explanation

(a)Explanation of terms used in animal production

(i)Flushing

Flushing is the practice of feeding female animals with good quality feed 2-3 weeks before and after mating with a male animal in order to increase conception rate.

(ii)Castration

This is the process of removing the testicles of a male animal or rendering the testicles unproductive by cutting off blood and nerve connections to the testicles.

(iii)Culling

This is the removal of unproductive/diseased/aggressive birds from a flock.

(b)Advantages of terms

(i)Flushing

• Increases the chances of multiple births
• Improves the health of female animals/prepares the animal’s health for conception
• Enables the female animal to withstand the stress and strains of pregnancy

(ii)Castration

• Prevents indiscriminate mating
• Removes bad/unpleasant/strong odour from the meat of male animals e.g. goat
• Makes male animals docile and easy to handle
• Enhances feed conversion/efficiency ratio/increases carcass weight of male animals
• Improves the quality of meat
• Prevents sexually transmitted diseases
• Prevents perpetuation of undesirable characteristics/traits

(iii)Culling

• Removes unproductive birds from the flock
• Reduces wastage of feed on unproductive/diseased birds
• Removes aggressive/cannibalistic birds from the flock
• Creates more space for productive birds
• Reduces the spread of diseases

(c)Functions of survey equipment

(i)Prismatic compass

• For determining position and displacement
• Taking bearings
• Measuring angular distances

(ii)Measuring tape

• For measuring lengths (horizontal and vertical)
• Determining definite points on straight lines
• Marking right-angle triangle during farm layout

(d)Difference between floriculture and aquaculture

Floriculture is the production and management of ornamental plants such as trees, shrubs and flowers

While

Aquaculture is the production of fishes and other aquatic animals in different water bodies

Correct Answer: D. inbreeding

Correct Answer: B. presence of tsetseflies

Correct Answer: D. 6.5 - 7.5

Explanation

The ideal pH of coffee is between 6.5 to 7.5. Therefore, choice D is correct.

Correct Answer: D. uprooting the weeds

Correct Answer: D) poor utilization

Correct Answer: D. slightly acidic

Explanation

(a)(i) Aim of the experiment

• Separation of soil into its fractions/determination of soil texture by sedimentation

(ii)Naming of the parts labelled I and II

I –Clay in suspension/Clay

II –Silt

(b)Description of the experiment

• Place a glass jar on a surface
• Weigh about 70 – 100g of the soil
• Add the weighed soil into an equivalent quantity of water in a glass jar
• Add suitable dispersing agent e,g, NaOH, NaHCO3
• Shake the glass jar vigorously to disperse any soil clods
• Allow the glass jar to settle for an hour
• Observe the result

(c)Properties of sandy soils

• Low cation exchange capacity
• Diameter is between 0.02 mm – 2m2
• Well drained, loose and highly aerated
• Low plant nutrients
• Low buffering capacity
• Leaching of nutrients is high/supports leaching
• Easily gets hot and cold
• Low water holding capacity
• Particles are light and easy to till
• Gritty/rough/coarse in nature
• High percolation rate
• Low capillary action
• Cannot be moulded

(d)Testing soil acidity using litmus paper

• Mix the soil very well
• Moisten with distilled water
• Dip red and blue litmus paper into moistened soil
• If blue litmus paper changes pink/red, the soil is acidic
• If red litmus paper changes blue, the soil is basic/alkaline
• If there is no colour change, the soil is neutral