Question 3
The diagram below illustrates a crop plant. Study it and answer the questions that follow.
(a) Identify the illustrated crop. (1 mark)
(b) Name the parts labelled I, II and III. (3 marks)
(c) (i) Mention two insect-pests of the illustrated crop. (2 marks)
(ii) Give two ways of controlling insect-pests of the crop plant. (2 marks)
(d) (i) Mention one method of harvesting the part labelled II. (1 mark)
(ii) Give two steps involved in the processing of the part labelled II after harvesting. (2 marks)
(e) State four uses of the illustrated crop. (4 marks)
Observation
(a) Many candidates were unable to identify the cotton plant with some of them writing cotton as the illustrated crop. Candidates could not also name parts of the cotton plant with some of them labelling the lint as cotton(b) Many candidates could not give the steps involved in processing the lint after harvesting. The expected answers include:
3. (a) (i) Identification of crop
- Cotton plant/ Gossypium spp (b) Naming of labelled parts
I - Leaf
II - Lint
III - Calyx
(c) (i)Insect- pests of cotton
- Cotton stainer/Dysdercus spp
- Aphid
- Boll worms
- Mirids/Helopeltis
- White fly
- Sucking bug
- Thrip
- Grasshopper
- Spider mite
(ii) Ways of controlling the insect-pests of the crop
- Handpicking
- Destruction of infested plant
- Spraying with recommended insecticides
- Destruction of alternative hosts around the farm
(d) (i) Method of harvesting the part labelled II (lint)
- Handpicking
- Mechanical harvesting (ii) Steps involved in the processing of the part labelled II (lint) after harvesting - Ginning
- Grading
- Spinning
- Dyeing
- Weaving
- Baling
(e) Uses of cotton
- Cotton lint is used in textile industries for making clothes
- Cotton seed oil is used for cooking
- Cotton seed cake is used as livestock feed
- Cotton lint is used for dressing wounds
- The leaves are used as medicinal herbs
- Used for padding fragile materials
- Used in filling pillows and mattress
- Cotton buds for cleaning the ear