Revision on Classification of Crops – JSS1 Agricultural Science Lesson Note (Second Term)

Crop classification according to use is the grouping of crops by what we mainly use them for, such as food, drink, animal feed, latex, fibre or oil.

Behavioural objectives

By the end of the lesson, students should be able to:

1. state the main groups of crops according to their uses;
2. describe each group of crops in one or two sentences;
3. give examples of crops in each group;
4. name crops that belong to more than one group.

What is a crop?

A crop is a plant that farmers grow on purpose for food, feed or other useful products.

• Food: crops such as yam, rice and beans feed people.
• Feed: crops such as elephant grass feed farm animals.
• Raw materials: crops such as cotton and rubber supply industries.

How are crops classified according to their uses?

There are ten main groups of crops by use: cereals, legumes, sugar crops, beverages and stimulants, roots and tubers, fruits, forage crops, latex crops, fibre crops and oil crops.

What are cereals?

Cereals, or grain crops, are grasses grown for their seeds.

• Family: they belong to the grass family.
• Use: the grains are food for people and feed for animals.
• Examples: maize, sorghum (guinea corn), millet, rice, wheat and acha.

What are legumes (pulses)?

Legumes are crops whose seeds are eaten and are a good source of plant protein.

• Importance: the protein helps the body to grow and repair itself.
• Examples: soya bean, cowpea, groundnut and bambara nut.

What are sugar crops?

Sugar crops are crops grown to make the sugar we eat.

• Sugarcane: a tall grass whose stem is crushed to get sugar juice.
• Sugar beet: a plant whose swollen root is used to make sugar.

What are beverages and stimulants?

Beverage and stimulant crops are crops whose products are used to make non-alcoholic drinks or to increase body activity.

• Cocoa: the seeds are processed into cocoa powder for drinks.
• Tea and coffee: used to make hot drinks.
• Kola nut: chewed as a stimulant.
• Tobacco: a stimulant crop, but harmful to health when smoked.

What are roots and tubers?

Root and tuber crops are crops that store food materials in the underground parts of the plant.

• Cassava: a root crop used to make garri and fufu.
• Sweet potato: a root crop eaten boiled or fried.
• Yam: a tuber crop eaten boiled, roasted or pounded.
• Cocoyam: a crop with underground corms and cormels used as food.

What are fruit crops?

Fruit crops are crops grown for their fruits, which are eaten fresh or canned.

• Examples: mango, orange, banana, cashew, pawpaw, guava and pineapple.
• Value: fruits supply vitamins and are also made into juice.

What are forage crops?

Forage crops are crops grown mainly as feed for farm animals.

• Grasses: elephant grass and gamba grass.
• Legume forage: alfalfa.
• Food crops as forage: some food crops are harvested before they are mature to feed livestock.
• Examples of such crops: maize, sorghum, millet, groundnut, soya bean and cowpea.

What are latex crops?

Latex crops are crops that give a white sticky sap called latex.

• Source: the latex is obtained from the stem or fruit of the plant.
• Example: rubber, also called para rubber.
• Use: latex is processed into tyres, gloves and other rubber goods.

What are fibre crops?

Fibre crops are crops that give thread-like fibres, which are processed into cloth and other materials.

• Cotton: fibre comes from the fruit (the boll).
• Sisal: fibre comes from the leaves.
• Jute and kenaf: fibre comes from the stems.

What are oil crops?

Oil crops are crops whose seeds or fruits give oil when processed.

• Oil palm: palm oil comes from the fruit.
• Coconut: coconut oil comes from the dried kernel.
• Sunflower: oil comes from the seeds.
• Groundnut, soya bean and cotton: oil comes from the seeds.

Which crops belong to more than one group?

Many crops belong to more than one group because they have more than one use.

Evaluation

1. Name the ten groups of crops classified according to their uses.
2. What are cereals? Give four examples.
3. Why are legumes important in our diet?
4. What is the difference between a root crop and a forage crop?
5. Name three crops that are both oil crops and members of another group.

Assignment

1. List four examples each of fruit crops and fibre crops.
2. Explain why some food crops are also grown as forage crops.