Classification Of Crops Based On Life Cycle And Morphology

CONTENT

• Meaning of Life Cycle
• Annual Crops
• Examples of Annual Crops

CLASSIFICATION OF BASED ON ITS LIFE CYCLE

LIFE CYCLE OF A CROP

Lifecycle of a crop is the number of years it will take the crop to germinate, mature, flower, produce seeds and die.Crops can be classified into three classes on the basis of their life cycle, the classes are:

(A) annual

(B) biennial

(C) perennial

Annual Crops: Annual crops are the crops that grow and complete their lifecycle within one year. They germinate, mature, flower, produce seeds and die within one year. Examples of annual crops are cotton, maize, cowpea and millet.

Biennial Crops: Biennial crops are crops that take two years to complete their life cycle. In the first year, they produce leaves and branches, in the second year, they produce and store food, flower have fruits and then die. Example of biennial crops are; cassava, onion, carrot and cocoyam.

Perennial Crops: Perennial crops are crops that take more than two years to complete their life cycle. Example of perennial crops are; mango, cocoa, pawpaw, oil palm, rubber etc.

EVALUATION

1.          What is meant by life cycle of a crop?

2.         list the various classes of crops based on their life cycle.

CLASSIFICATION OF CROPS BASED ON MORPHOLOGY

There are two broad classes of crops based on what they look like (morphology). They are

1. Monocotyledons and
2. Dicotyledons

MONOCOTYLEDONS

Monocotyledons are plants that have seeds which possess just one cotyledon each or one seed leaf, example of monocotyledons are palms, cereal e.g. rice, millet, guinea corn, maize , oil palm etc,

CHARACTERISTICS OF MONOCOT

1. They have fibrous roots i.e. the roots are almost of the same size.
2. They have long slender hollow stem which bear few or no branches.
3. The stems are soft, that is they lack cambium tissue, a layer which is responsible for the thickening of stem in dicotyledons.
4. The leaves are long and narrow.
5. The leaves have parallel veins, that is main veins which are parallel to one another.
6. They have one seedleaf.

EVALUATION

1. What are monocotyledons plants?
2. State fiveexamples of monocots.
3. Draw a monocot plant and label.

DICOTYLEDON PLANTS

Dicotyledons are plants that have seeds with two cotyledons each or  two seed leaves.When the seeds split open, they give two parts. These are cotyledons. Examples of dicotlyledons are cowpea,soyabean, cotton, groundnut, orange, mango, tomato, waterleaf etc.

CHARACTERISTICS OF DICOT PLANT

1. They have tap root.
2. They have a main stem bearing several branches.
3. They have cambium tissue in their stem.
4. Their leaves are short and broad.
5. Leaves have net venation.
6. They have two seedleaves
7. They have leaves with petioles or stalks.
8. Their flowers have either five or multiple of five parts.

EVALUATION

1. What is dicot?
2. List five example of a dicotyledon plant.
3. Mention three characteristics of dicotyledon plants.

DIFFERENCES BETWEEN MONOCOT AND DICOT PLANTS

GENERAL EVALUATION AND REVISION QUESTIONS

1. What are monocot plants?
   1. What are dicot plants?
   1. Give five examples of monocot plants.
   1. Give five examples of dicot plants.
   1. In tabular form,distinguish between monocot and dicot plants.

READING ASSIGNMENT

Junior Secondary Agriculture for Nigerian Schools by A. Yondeowei Bk. 1. Chapter 3, pages 23.

WEEKEND ASSIGNMENT

1. Dicotyledonous plants have ___ (a) One cotyledons (b) two cotyledons  (c) three cotyledons (d) four cotyledons
2. The following are example of dicot plants except

(a) cowpea (b) groundnut (c) soybeans  (d) Maize.

• Which of these crops is not an annual crop? (a) cotton  (b)  cowpea  (c) cocoa (d) orange
• The leave of tomato plant possesses what type of venation (a) parallel (b) Net (c) vertical (d) cross.
• Crops that complete their life cycle in more than two years are called _________

(a)        Perennials  (b) Biennials  (c)  Annuals (d) Decennial

THEORY                                          

1.          a.   Define dicotyledonous  plant.

            b.   State five examples.

2.         Outline five characteristics of dicot plants.

3.         Mention three examples of annual crop.