Abstract:
Chlorophyll and Nitrogen are related to each other. Estimating one will help to predict the
other. Many techniques are invented to estimate these two. In many cases evaluation of
chlorophyll and nitrogen content in plants need to destructive methods, more time and
organic solvents. Laboratory plant testing was usually time-consuming and high-costing.
Hence, plant nutrient variability must be measured rapidly and the information made known
to the farmers before the new season starts. The objectives of this paper was to evaluate the
leaf chlorophyll content of different leaf colors in crop growth stage to determine leaf
nitrogen content with non-destructive methods in crop leaves. SPAD-502 meter and CCM200 meter were two reliable measurements for total chlorophyll content and chlorophyll
content index respectively. Different leaf colors of three field crops (maize, wheat & barley)
and one perennial crop(coffee leaves) were selected to compare the performance of a
handheld SPAD Chlorophyll meter and CCM-200 chlorophyll meter reading for total leaf
chlorophyll and chlorophyll content index. Leaves were sampled and Chlorophyll was
quantified using these two methods. Both techniques were compared against nitrogen content
of leaf analyzed using standard laboratory procedures (Kjeldahl method).Mean comparison
among the treatments (leaf colors) explained highly significant difference (p<0.001) with
those two parameters (SPAD, CCM&N) at both growth stage. Significant correlations
(r
2
=0.74, 0.88, 0.80&0.96 at vegetative and r
2
=0.93, 0.91, 0.54 &0.74 at flowering) were
observed between total leaf chlorophyll (SPAD-502 reading) and chlorophyll content index
(CCM-200reading) as well as (r
2
=0.96, 0.84, 0.99&0.99 at vegetative and r
2 =0.92, 0.86,
0.82&0.90 at flowering) for both reading with leaf N concentration (LNC) in all crops. From
the result, the color of crop leaves was closely correlated with nitrogen (N) status and can be
quantified easily with SPAD-502 meter and CCM-200 meter. The establishment of the
relationship between SPAD-502 meter and CCM-200 meter reading and N status of leaf were
important for crop monitoring and N diagnosis in the field at different crop growth stage.
