You can relate the SPAD meter reading with the chlorophyll content. Further, there is scope for chemotyping by applying AI-ML for better prediction of N and chlorophyll content.

May I know in which crop you have got different reading on the same leaf?

Sagar Maitra Mungbean

Sina Shaffiee Haghshenas Rajesh Kumar Meena Dinesh Kumar Dr Rakesh Kumar Hardev Ram

SPAD meter read the intensity of green color of leaves which is directly proportionate to the the chlorophyll content of the leave. There is a possibility of leaves do not have same amount of chlorophyll content in all the parts/portions or there may be very slight color/shade differences within the different parts of leaves which we are not able to differentiate with our eyes. That is the possible reason you are getting different values in different parts of leaves. For this, you need to follow appropriate procedure to use SPAD or any other chlorophyll meter and average of 10 leaves may be considered as mean value. Further, following the appropriate procedure/formula the SPAD meter reading can be related to the the chlorophyll content of leaves.

Dinesh Kumar , Got it sir, Thank You