Growth can be measured in various ways, including fresh weight, dry weight, length, and area. A typical growth curve has three phases: a lag phase with slow growth, a log phase with maximum growth, and a stationary phase where growth levels off. Growth analysis involves expressing the plant growth rate as a product of factors like net assimilation rate (carbon assimilation minus respiration) and leaf area ratio (proportion of plant that is leaves). Crop growth rate is dry matter accumulation per unit land area over time. Relative growth rate measures dry matter increase relative to existing dry matter.

2. GROWTH
Growth is defined as an irreversible increase in mass,
weight or volume of a living organism, organ or cell.

3. GROWTH CURVE
A typical growth curve can be
divided into three phases:
Lag phase
Log phase
Stationery phase

4.  Lag period of growth:
The growth rate is quite slow because it is the
initial stage of growth.
 Log period of Growth:
The growth rate is maximum and reaches the
top because at this stage the cell division and
physiological processes are quite fast.
 Senescence period (steady state period)
The growth is almost complete and become
static. Thus the growth rate becomes zero.

6. Measurement of growth
Growth can be measured by a variety of
parameters as follows:
 Fresh weight
Determination of fresh weight is an easy and
convenient method of measuring growth.For
measuring fresh weight,the entire plant is
harvested,cleaned and then weighed.
Dry weight
The measurement of dryweight may give a
more valid estimation of growth than fresh
weight.The dry weight of a plant organ is obtained
by drying the material for 21 to 48hrs at 70 to 80°C
and weighing it.

7.  Length
Measurement of length is a suitable indication of
growth for those organs which grow in one direction
such as roots and shoots.The advantage of measuring
length is that it can be done over the same organ over a
period of time without destroying the organ.
Area
It is used to measure the growth of organs like
leaf.The area can be measured using graph paper or by
electronic leaf area meter which reads leaf area directly
as individual leaves are fed into it.

8. GROWTH ANALYSIS
It is the process of analyzing the plant growth rate by
expressing it as algebraic product of a series of
factors.
The plant parameters, which are commonly
measured to calculate growth rates,are dry matter
and leaf area.

9. CROP GROWTH RATE
It is defined as the dry matter accumulation
rate per unit land area per unit time. The CGR is
calculated by the following formula
W2 - W1
CGR = ---------------- (g m-2 d-1)
A (T2 - T1 )
Where CGR is the crop growth rate, W1 and W2 are
the dry weights at two sampling times T1 and T2
respectively. A is the area occupied by the plants

10. RELATIVE GROWTHRATE
 It is defined as the rate of increase in dry matter per
unit of dry matter already present.
 This is also referred as Efficiency index .
 It provides a valuable overall index of plant
growth. The mean relative growth rate over a time
interval is given below.
LogeW2 - LogeW1
 RGR = --------------------------- (g g-1 d-1)
T2 - T1
 RGR = NAR X LAR

11. NET ASSIMILATION RATE
 It is the dry matter accumulation per unit of leaf
area.
 The NAR is a measure of the amount of
photosynthetic product going into plant material
i.e. it is the estimate of net photosynthetic carbon
assimilated by photosynthesis minus the carbon
lost by respiration.
 It is expressed as (g cm-2 wk-1 )
NAR=1/A ×dw/dt

12. LEAF AREA RATIO
 The LAR is a measure of the proportion of the plant
which is engaged in photosynthetic process.
 It is defined as the ratio between leaf area in square
centimeters and total plant dry weight. It
represents leafiness character of crop plants on
area basis.
A
LAR=---(cm2g-1)
W

13. SPECIFIC LEAF AREA
 It is another component of LAR and defined as the
ratio between leaf area in cm2 and total leaf dry
weight in grams. This is used as a measure of leaf
density. The mean SLA can be calculated as
A
SLA = -------- (cm2 g-1)
WL

14. SPECIFIC LEAF WEIGHT
 The reversal of SLA is called as SLW. It is defined as
the ratio between total leaf dry weight in gms and
leaf area in cm2.
 It indicates the relative thickness of the leaf of
different genotypes.
WL
SLW = ------- (g cm-2)
A

15. LEAF AREA INDEX
 It is defined as the functional leaf area over unit
land area. It represents the leafiness in relation to
land area. At an instant time (T) the LAI can be
calculated as
LAI = A/P (unit less)
 For maximum production of dry matter of most
crops, LAI of 4-6 is usually necessary

16. LEAF AREA DURATION
 It is usually expressed as a measure of leaf area
integrated over a time period. Some takes into
account both the magnitude of leaf area and its
persistence in time.
 It represents the leafiness of the crop growing
period. Thus the unit of measurement of LAD may
be in days or weeks or months.
 This is expressed as cm2d -1

17. ABSOLUTEGROWTHRATE
 It is the function of amount of growth material
present and is influenced by environment.
 It gives absolute value of biomass between two time
intervals.
 It is mainly used for a single plant or single plant
organ etc.
AGR = H2-H1 / T2- T1
Where H1 and H2 are plant heights at times T1 and T2