Course of growth/ Growth Curve (Grand Period of Growth)

The course of growth can be divided into four parts:

• Lag Phase
• Log Phase (Exponential or Linear Phase)
• Decreasing / Stationary / Steady Phase
• Death phase or Senescent Phase

a. Lag Phase:

• It is an initial growth phase. During this phase, little growth occurs. Events that occurs in this phase include germination and vegetative growth.
• The increased in size or weight is very slow or negligible.

b. Log Phase (Exponential or Linear Phase):

• It is usually a short phase, and there is rapid growth.
• The rapid growth rate continues when the plant develop its photosynthetic mechanisms
• Therefore , this phase is also called exponential phase or Grand Period of Growth
• In all cases of growth, the log phase declines and the rate of growth begins to decrease
• The point at which this occurs is known as the inflection point

c. Decreasing / Stationary / Steady Phase:

• In this phase, the rate of growth declines again after the log phase

• In this phase, the flow of food to the vegetative organs is finally ceased
• Plant activities in this phase include cell maturation

d. Death phase or Senescent Phase:

• After a period of maximum growth, there is a period of negative (senescence) before the death of the plants

Fig : lag , log and steady phase