Classification of Crops (Annual, Biannual, Perennial) – JSS1 Agricultural Science Lesson Note (First Term)

Crops are classified by lifespan into annual, biennial and perennial crops. An annual crop completes its life cycle from seed to seed within one growing season. A biennial crop needs two years to complete its life cycle. A perennial crop lives for many growing seasons.

Behavioural objectives

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

• state the three groups of crops based on lifespan;
• define annual, biennial and perennial plants;
• explain how annual plants survive from one generation to the next;
• describe what happens to the top part of a perennial plant each winter.

How are crops classified based on lifespan?

Crops are classified based on lifespan into annual, biennial and perennial crops.

What are annual plants?

Annual plants perform their entire life cycle from seed to flower to seed within a single growing season. All the roots, stems and leaves of the plant die annually. Only the dormant seed bridges the gap between one generation and the next.

What are biennial plants?

Biennial plants require two years to complete their life cycle.

What are perennial plants?

Perennial plants persist for many growing seasons. Generally, the top portion of the plant dies back each winter and regrows the following spring from the same root system (e.g. Purple Coneflower). Many perennial plants keep their leaves year-round and offer attractive borders and groundcovers (e.g. Tickseed, Shasta and Ox-eyed Daisy).

An Ox-eyed Daisy

Evaluation

1. Name the three groups of crops based on lifespan.
2. Define an annual plant.
3. How long does a biennial plant take to complete its life cycle?
4. Which part of an annual plant lives on from one generation to the next?
5. What happens to the top portion of a perennial plant each winter?

Assignment

Write short notes on annual, biennial and perennial plants. Give one example of a perennial plant from the note.