Describe three cultural and two chemical control methods for parasitic weeds such as Striga.

1. Explain five mechanisms by which weeds affect crop yields. (5 mk)
2. Describe three cultural and two chemical control methods for parasitic weeds such as Striga. (5 mk)
3. Explain the meaning of the following as used in weed science: (i) Annual weed (ii) Biennial weed (iii) Perennial weed (iv) Creeping weed (v) Parasitic weed (10 mk)
4. Explain five mechanisms by which weeds affect crop yields. (5 mk)
5. Describe three cultural and two chemical control methods for parasitic weeds such as Striga. (5 mk)
6. Explain the meaning of Creeping weed. (1 mk)
7. Explain the meaning of Parasitic weed. (1 mk)

Upgrade to see model answers.

State four characteristics a breeder should consider when developing rice varieties for disease resistance.

1. Define each of these crop breeding terms: inbreeding depression, hybrid breakdown, pureline, synthetic variety. (8 mk)
2. State four characteristics a breeder should consider when developing rice varieties for disease resistance. (4 mk)
3. Describe pedigree and backcross breeding methods. For each, state one advantage and one disadvantage. (8 mk)
4. Describe backcross breeding method, stating one advantage and one disadvantage. (3 mk)
5. State four characteristics a breeder should consider when developing rice varieties for disease resistance. (4 mk)
6. Define synthetic variety. (1 mk)

Upgrade to see model answers.

Describe five signs by which a farmer can detect viral infection in vegetable crops.

1. For each of the following diseases, give causative agent, five symptoms, and two control measures: (i) Late blight of potatoes (ii) Cassava mosaic (12 mk)
2. Describe five signs by which a farmer can detect viral infection in vegetable crops. (5 mk)
3. Describe five signs by which a farmer can detect viral infection in vegetable crops. (8 mk)
4. For cassava mosaic, give causative agent, five symptoms, and two control measures. (5 mk)

Upgrade to see model answers.

Discuss the advantages and disadvantages of using genetically modified crops.

1. What are pesticide adjuvants? Explain the roles of each of the following adjuvants: sticker, spreader, emulsifier. (10 mk)
2. What are pesticide adjuvants? Explain the roles of each of the following adjuvants: sticker, spreader, emulsifier. (5 mk)
3. Outline six safety precautions to take during pesticide mixing, spraying, and disposal of pesticide containers. (6 mk)
4. Discuss the advantages and disadvantages of using genetically modified crops. (5 mk)
5. Outline six safety precautions to take during pesticide mixing, spraying, and disposal of pesticide containers. (10 mk)

Upgrade to see model answers.

Describe the nature, symptoms, and control of each of these fungal crop diseases: (i) Fusarium wilt of bananas (ii) Black Sigatoka of bananas (iii) Head smut of sorghum (iv) Rice blast (v) Stem rust of wheat

1. Fusarium wilt of bananas (4 mk)
2. Black Sigatoka of bananas (4 mk)
3. Head smut of sorghum (4 mk)
4. Rice blast (4 mk)
5. Describe the nature, symptoms, and control of Rice blast. (3 mk)
6. Stem rust of wheat (4 mk)
7. Describe the nature, symptoms, and control of Stem rust of wheat. (3 mk)

Upgrade to see model answers.

Explain five environmental factors that affect feed intake in animals.

1. Describe two consequences of mineral deficiencies in dairy cattle. (4 mk)
2. Explain five environmental factors that affect feed intake in animals. (6 mk)
3. Define fat soluble vitamins. (1 mk)
4. Define fat soluble vitamins. (1 mk)

Upgrade to see model answers.

Describe three signs and three preventive measures of Newcastle disease in poultry farming.

1. Describe four methods by which tsetse flies may be controlled in pastoral regions. (8 mk)
2. Explain five effects of parasites on livestock health and productivity. (10 mk)
3. Describe three preventive measures of Newcastle disease in poultry farming. (4 mk)

Upgrade to see model answers.

State four hormones involved in cow reproduction. For each, briefly explain its role.

1. List and explain the phases of the oestrus cycle in the cow. (6 mk)
2. State four hormones involved in cow reproduction and explain their roles. (4 mk)
3. Describe the role of the cloaca in egg formation. (2 mk)

Upgrade to see model answers.

Propose six factors to consider when formulating rations for high-producing dairy cows.

1. Propose six factors to consider when formulating rations for high-producing dairy cows. (9 mk)
2. Calculate the digestibility coefficient of the DM. (5 mk)
3. Define production requirement. (2 mk)

Upgrade to see model answers.

Identify and explain four desirable qualities of pasture grasses in semi-arid regions.

1. Identify and explain four desirable qualities of pasture grasses in semi-arid regions. (8 mk)
2. Compare zero grazing with free range grazing, giving advantages and disadvantages of each. (10 mk)
3. Describe its benefits for both land and livestock. (4 mk)

Upgrade to see model answers.