Classification of crops according to their Physiological and Biochemical Characterization

Mode of Photosynthesis

C₃ Plants or Insufficient Plants

During the Photosynthesis some plants fix CO₂ and form the three carbons Molecule, 3 phosphoglyceric Acid (3PGA). Usually plants of this Category fallow the Calvin Cycle for CO₂ assimilation.

Such Plants can’t use the water, light and resources efficiently so these are called insufficient plants.

Examples: Wheat, Oat, Rice, Soyabean, Banana, Cotton and rye.

C₄ Plants or sufficient Plants

In these plants the first fix the CO₂ and form the four carbon molecule during the photosynthesis. Usually these fallow the Hatch and Slack pathway of assimilation of CO₂.

These do not exhibit the photorespiration so far they are the efficient in the use of water, light and resources.

Examples: Sugarcane, Sorghum, Maize

CAM Plants (Crassulation Acid Metabolism)

They fix the CO₂ as the C₄ But fixation of CO₂ occur during the night they open the stomata duriong the night.

Examples: Pineapple, Pickly pear.

Mode of Propagation

Sexually Propagated Plants 

These plants are propagated through the seed.

Example: Wheat, Barley, Rice, Cotton, Maize, Sorghum

Asexually or Vegetative Propagated Plants

Those plants which are propagated through asexually using some specialized parts of plants

Example: Sugarcane, Potato, Garlic, Some fruits and ornamental plants

Mode of Pollination

Self-Pollinated plants

Those plants in which the pollen from one anther is transferred to the stigma of the same plant

Example: Wheat, Barley, Rice, Soybean, Sorghum

Cross-pollinated Plants

In these plants pollen from one plant is transferred by the insect, wind or any other mean to the stigma of another plant.

Example: Maize, Brassicas, Sunflower

Growth Habits

Determinate Plants

Those plants which initiate their reproductive stage after the completing of the vegetative growth

Example:  Wheat, Barley, Rice

Indeterminate Plants

In these Plants Vegetative and reproductive stages continue simultaneously

Example: Tomato, Okra, eggplant, Cucumber, Watermelon, Cotton.

Photo period

Long Day Plants

Those plants which change from vegetative stage to reproductive stage by producing flowers and fruits when the days become longer

Example: Wheat, Barley, Oat, Gram

Short Day Plants

Those plants which change from vegetative stage to reproductive stage by producing flowers and fruits when the days become shorter

Examples:  Rice, Soybean.

Day Neutral Plants

Those whose initiation of the flowering is not effected by day length

Tomato, Cucumber, Maize

Root System

Tap Root

A taproot system is one in which the primary root becomes the main root of the plant with minimal branching consisting of secondary, smaller lateral roots. The taproot system occurs in dicot plants

Example: Gram, Pea, Sarsoon, Cotton, soybean,

Fibrous Root

A fibrous root system (sometimes also called adventitious root system) is usually formed by thin, moderately branching roots growing from the stem. A fibrous root system is universal in monocotyledonous plants

Example: Wheat, Rice, Maize, Sugarcane, Sorghum

Seed Classification

Monocotyledon seed plants

The plants have only one cotyledon in their seed

Example: Rice, Wheat, Maize, Sugarcane, Sorghum

Dicotyledonous Plants

Those plants whose have two cotyledon in their seed

   Example: Gram, pea, reddish, potato, pumpkin, coriander, spinach, coffee, cotton, sunflower, soybeans

Mode of Germination

Epigeal Germination

In this type of germination seed/ Cotyledon emerge out of the soil or above the soil

             Examples: Cotton, Gram, Soybean,

              Hypogeal Germination

In this type of germination seed/ Cotyledon remain in the soil or below the soil

Example: Wheat, Rice, Maize and Monocots

Author: Imran Ramzan*, Arslan Shehroz¹, Muhamamd Zunair Latif²,

Author * Department of Agronomy, University of Agriculture Faisalabad

¹&² Co-author Department of Plant pathology, University of Agriculture Faisalabad

E-mail: [email protected]