Types of Plant Growth

Lt = Lo + rt

Where
Lt = Length at time ‘t’
Lo = Length at time ‘Zero’
r = Growth rate
t = Time of growth

\[\mathbf{W}_{1}=\mathbf{W}_{0}\mathbf{e}^{n}\]

Where
W₁ = Final size
W₀ = initial size
r = growth rate
t = time of growth
e = base of natural logarithm

• Two Types — Plant growth is of two types: Arithmetic and Geometric, differing in rate and pattern of cell division.
• Arithmetic Growth — Rate of growth is constant. One daughter cell divides, the other differentiates. Example: root elongation. Produces a linear curve.
• Geometric Growth — Both daughter cells keep dividing repeatedly. Growth is slow initially but later becomes rapid and exponential. Produces a sigmoid (S-shaped) curve.
• Sigmoid Curve Phases — Lag phase (slow) → Log phase (rapid/exponential) → Stationary phase (growth stops). This is the characteristic curve of most living organisms.