(a) What is natural pasture? (2 marks)
(ii) State four characteristics of natural pastures in West Africa. (4 marks)
(b) Discuss the root knot disease of tomato under the following headings: (i) causal organism; (ii) mode of transmission; (iii) two symptoms; (iv) two prevention and control measures.(6 marks)
(c) Distinguish between grafting and budding in plant propagation. (2 marks)
(d) Give two uses of sugarcane. (2 marks)
Explanation
(a)(i) Meaning of natural pasture: This is a naturally occuring area of land containing grasses and legumes used for feeding livestock such as cattle, sheep and goats.
(ii) Characteristics of natural pastures in West Africa:
-Generally found on flat land.
-The area is usually covered with grasses and legumes.
-Generally the pasture is of low quality.
-Ability to regenerate rapidly.
-Ability of the grasses and legumes to withstand pests.
-Ability of the grasses and legumes to withstand disease outbreak.
-It contains obnoxious grasses and legumes.
-Ability to withstand trampling.
-Ability of the grasses and legumes to withstand drought.
(b) Discussion on root-knot disease of tomato:
(i) Causal organism: - Rootknot nematode/ Meloidogyne spp.
(ii) Mode of Transmission:
- Nematodes are soil borne so are transmitted through soil movement and run-off water.
-Through vegetative planting materials/transplanting of seedlings.
-Through contaminated farm tools and equipment.
(iii) Symptoms:
- Enlargement of certain cells of the roots in the form of knots.
-Retarded growth.
(iv) Prevention and control measures:
- Crop rotation.
- Use resistant varieties.
- Use nematicides such as furadan.
- Use ofAfrican marigold (biological control).
- Heavy doses of organic matter application.
- Soil sterilization.
(c) Distinguish between grafting and budding in plant propagation: In grafting, the scion contains more than one bud, whereas in budding only one bud is used as scion. (d) Uses of sugarcane:
(i) Production of molasses. (ii) Manufacture of sugar. (iii) Manufacture of ethanol, acetone, citric acid, glycerol, etc. (iv) Wastes as animal feed. (v) Production of bargasse for fuel and animal feed. (vi) Used as substrate for the production of brewers and bakers yeast (Torulopsis utilis). (vii) Production of a high protein food yeast from molasses. (viii) Used for medicinal purposes.