Bomet County Joint Examinations - 2015

BOMET COUNTY JOINT EXAMINATIONS - 2015 443/1 AGRICULTURE SECTION A (30 MARKS) 1. Reasons why shifting cultivation is discouraged  Produces low yield per unit area  Time wastage in shifting to new grounds  No incentives to develop land  Not applicable in areas with high population /needs large piece of land ( 3 x ½ = 1 ½ marks) 2. Ways in agriculture support agro- based industries  Source of raw materials for the industries  Provide market for industrial goods  Provide income for starting the industries (3 x ½ = 1 ½ marks) 3. Common deficiency symptoms for Nitrogen and Potassium in crops:  Chlorosis  Student growth ( 2 x ½ = 1 mark) 4. Sources of phosphorus in the soil  Phosphatic fertilizer  Decomposition of organis matter  Organic manures / mulches ( 2 x ½ = 1 mark) 5. Functions of iron in plants  Part of chlorophyll / chlorophyll formation  For synthesis of proteins in chlorophyll  Important co- enzyme/ needed in enzyme controlled reactions (2 x ½ = 1 mark) 6. Fertilizer grade indicates the amount of nutrient (NPK) present in a fertilizer e.g 20:20:20 on percentage basis, while Fertilizer ratio is relative proportion of the three primary macro- nutrients in a fertilizer e.g 1:1:1 as ratio of NPK (2 x ½ = 1 mark) 7. Factors that determine the effectiveness of a herbicide  Stage of growth of weed  Plant morphology and anatomy  Plant physiology / metabolic factors within the weed plant  Characteristics of the herbicide  Concentration of herbicide  Method of application of the herbicide (6 x ½ = 3 marks) 8. Disadvantages of tillage as a method of weed control in maize crop:  Destroy soil structure  Creates conditions suitable for growth of weeds  Labourious/ expensive on a large piece of land  Exposes land to erosion ( 3 x ½ = 1 ½ marks) 9. Underground structure in weeds that make control difficult: a) Nut grass: bulbs (1/2 mark) b) Couch grass Rhizomes (1/2 mark) 10. Mechanical method for controlling water hyacinth:  Shredding  Mechanical removal from the water ( 1 x 1 = 1 mark) 11. Advantages of drip irrigation  Little amount of water is used / economizes on the use of water  Water under low pressure can be used  Does not encourage growth of weeds between the rows  Discourages fungal diseases e.g CBD, blight ( 2 x ½ = 1 mark) 12. Benefits of agro- forestry other than soil and water conservation:  Source of income  Source of wood fuel/ labour saving  Has aesthetic value  Increases land value (2 x ½ =1 mark) 13. Land subdivision is the partition of a piece of land into small portions to be owned by different persons, while land fragmentation is a situation where a single farmer owns several parcels of land scattered over a wide area ( 2 marks ) mark as a whole 14. Settlement Schemes at Kenya’s independence  Z – plots ( 1 mark)  Jet schemes (1 mark) 15. (a) Steps of making baled hay from Rhode grass:  Cut the grass  Spread evenly on the ground to dry for 2-3 days  Wind- row the grass  Gather the grass  Bale the grass using baling machine / baler (5x ½ = 2 ½ marks) (b) Factors that determine the quality of hay from Rhodes grass:  Length of the drying period  Weather conditions during drying period  Presence of foreign materials / weeds Frequency of turning / windrowing(4 x ½ = 2 marks) 16. (a) (i) Gross Domestic Product: Is the sum total of goods and services produced by a country within a period of one year ( 1 mark) (ii) Per capita income is the average income of citizens of a country within a period of one year /gross national income divided by the size of population in a country. ( 1 mark) (b) Sources of agricultural credit Commercial banks  Crop Boards eg KTDA  Co-operative societies  Personal savings  Agricultural Finance Corporation (4 x ½ = 2 marks) 17. Types of labour records  Muster roll  Labour utilization analysis (2 x ½ = 1mark) SECTION B (20 MARKS) 18. (a) Maize stalk borer ( 1 mark) (b) Stage B: moth (1 mark) (c) Damage by pest in stage C: boring of the stem / stalk ( 1 mark) (d) Control measures for maize stalk borer:  Rogueing  Application of Endosulfan / Dipterex / Stalk borer dust down the maize funnel  Spray insecticide to kill the pest/ moths/ stage B / stage C  Field hygiene (3 x 1 = 3 marks) 19. (a) Tongue / whip grafting (1 mark) ( b) D: Scion (1 mark) ( c) Characteristics of part E/ rootstock:  Soil pH tolerant  Adapted to local conditions  Compatible to most species (2x 1 =2 marks) (d) Polythene / grafting tape/ banana stem ( 1mark) (a) % of moisture in the soil sample ( 2 marks) Mass of wet soil = 50-20 = 30g Mass of dry soil = 40- 20 = 20g Mass of moisture / water = 30 – 20 = 10g % of moisture = 10/30 x 100 = 33.33% (b) % of humus in the dry soil: Mass of humus lost = 40-35 = 5g Mass of dry soil =20g % of humus = 5/20 x 100 = 25% ( c) Role of humus in the soil ( 1 mark)  Gives colour to the soil  binds soil particles together, hence improve soil structure  Releases nutrients to the soil on decomposition 1 mark) (a) Breeding record ( 1 mark) (b) 23/4/2015 – 27/4/2015 ( 1 mark) ( c) Reasons for keeping pig breeding records  For culling / selection  To determine genetic potential of the sire  Control inbreeding / breeding  To tell the history of the farm enterprises ( 3 x 1=3) SECTION C ( 40 MARKS) 20. (a) Field production of carrots for fresh market: (i) Varieties (2 marks)  Nantes  Chantenary (2 x 1 = 2 marks) (ii) Land preparation (3 marks)  Clear the land  Carry out deep primary cultivation during dry season  Harrow to produce fine tilth  Remove all perennial weeds (3 x 1 = 3 marks) (iii) Planting (4 marks  Make drills with a stick / finger  Drills are spaced 20-30 cm apart  Put seeds singly in the drills  Apply DSP / DAP fertilizer at the rate of 90kg/ha in the drills thoroughly mixed with the soil  Cover the seeds lightly with the soil  Irrigate if dry season (4 x 1 = 4 marks) (iv) Field management practices and harvesting of carrots ( 6 marks)  Carry out thinning 2-3 weeks after germination to leave 3-4 cm between plants  Carry out weeding by uprooting / keep field weed free  Earth up the crop to allow for root expansion  Top dress with 60kg/ ha of N one month after germination  Carry out irrigation of the crop if there is no rain  Control aphids by spraying with insecticides  Carrots are mature 3-5 months after sowing  Harvest carrots by lifting / uprooting the plants out of the ground using fork jembe ( 6 x 1 = 6 marks) (b) Post harvest practices in grains before processing:  Threshing / shelling : to facilitate cleaning/ storage  Drying: to required moisture content ready for storage  Cleaning: to remove chaff/ foreign materials by winnowing / sieving  Sorting/ grading: according to quality / size/ cleanliness for ease of marketing  Dusting: with insecticide powders to control storage pests  Packing: for easy storage/ avoid contamination ( 5 x 1= 5marks) 21. (a) Stages of chemical water treatment for human consumption: Stage 1: Filtration at water intake  Water is made to pass through series of sieves to remove / trap large solid particles Stage 2: Softening of water  Water in pipes flow into a mixing chamber/ tank containing soda ash to soften the water and Alum to help coagulate solid particles which finally settle down at the bottom of sedimentation tank in stage 3 Stage 3: Coagulation and sedimentation  The softened water pass into coagulation tank where solid particles / silt settle down  Water stays in this tank for at least 36 hours to kill bilharzias worms Stage 4: Filtration  Water pass into filtration tank with different sizes of gravel in layers and a top layer of sand where all the remaining solid particles are removed  Water seeps through these layers slowly leaving all solid particles behind  When water leaves this tank, it is clean Stage 5: Chlorination  The filtered water then enters chlorination tank where a small amount of chlorine solution is added to kill germ/ . micro- organisms in the water Stage 6: Storage  Water is stored in large tank for distribution by pipes / use ( 6 x 1 = 6marks) (b) Methods of draining marshy land for pasture production.  Open ditches: U or V shaped ditches are dug to allow water flow by gravity, hence lower the water table;  Underground perorated drain pipes: these are laid to allow water to seep into the pipes and drain away into water ways  French drains: ditches are dug and filled with stones / graves, then covered with soil. This allows pasture to be grown  Cambered beds: raised beds are constructed and crops grown on top of the beds  Pumping water out of the ground: where possible to do so;  Planting eucalyptus trees: to absorb excess water from the land (4 x 1 = 4marks) (c) Five physical methods of soil and water conservation and how they work: Method How it works 1. Trash / stone lines  Trap soils  Reduce speed of run off  Form bench terrace 2. Bunds  Trap soil  Reduce speed of run off  Form bench terrace 3. Cut off drains (CODs)  Divert storm water away from farmlands; and discharge it into waterways;  Reduce speed of run off/ storm water 4. Terraces  Reduce surface flow of water  Carry away excess water which cannot be absorbed by soil 5. Gabions  Reduce speed of run off / reduce erosive force of running water;  Trap soils which are deposited in gullies;  Stabilize gullies 6. Check dam/ dam  Hold an store water  Reduce speed of run off  Check dam allows soil carried in water to settle down;

Methods: 5 x 1 = 5 marks Explanation: 5 x 1 = 5 mark 22. (a) Advantage of rotational grazing  Maximum use of pasture  Reduce build up of pests and diseases  Animal waste is distributed uniformly in the field  Excess can be harvested for conservation/ sale  It is possible to apply fertilizers in parts which are not in use / re- seeding and weeding can be done  Pasture area is given time to re-grow before it is grazed again (5 x 1 = 5mks) (b) Cultural methods of crop disease control:  Use of resistant varieties: to prevent / tolerate attack by pathogens  Crop rotation: break life cycle of pathogens  Use of certified / health planting materials: to prevent introduction of disease causing organisms in the field  Pruning: Prevent spread of diseases in the field/create un –conducive environment for pathogens  Correct spacing: prevent spread/ create un –conducive environment for pathogens  Timely planting/harvesting: to escape disease outbreak  Weed control: eliminate weeds that harbor pathogens / vectors  Control of vectors: prevent introduction / spread of pathogens in the field  Roguing/ Field hygiene: prevent spread of the disease in the field  Close season: break the life cycle of pathogens  Quarantine: prevent introduction of pathogens in the field  Use of heat treatment of planting materials : kill pathogens (10 x 1 = 10 marks) (c ) Advantages of propagation by use of seeds:  Saves on planting time as seed can be easily handled  Less bulky  Can be easily stored over a long period of time  Results in new plant varieties through cross pollination  It is cheapest method of propagation as seeds are easily available (5 x 1 = 5 marks)