The SPAD 502 Chlorophyll Meter can measure the chlorophyll content of leaves, and thereby enables to estimate indirectly the nitrogen status of plants. It is very efficient and non-destructive method. However, chlorophyll can be also extracted and determined spectrophotometrically from dried leaf disks. But is there any method or factor to change a SPAD chlorophyll content reading into micro gram per area (micro-gram per square centimeter)?
Hello! In fact, you need to calibrate SPAD by means of spectrophotometric analysis for each species you analyze. Also, leaf age and effect of environmental factors need to be taken into the account. We did something similar in the attached paper
It is always best to develop your own relationship curve for the species you are studying and the optical meter used to measure the relative chlorophyll content. This can be done by following the appropriate extraction procedures and spectrophotometric analysis. Although there are existing equations to convert SPAD or CCI (CCM-200 meter Opti-Sciences) units to a chlorophyll concentration. Be careful that if you do use one of the existing equations that they used the correct procedures and equations.
Yes, is is so easy by following formula:
Chl (µg cm-2)= (99 SPAD)/(144 - SPAD)
I dont know much but I read one paper where they shown conversion of SPAD values into Chlorophyll content.
you can find it here:
A new optical leaf-clip meter for simultaneous non-destructive assessment of leaf chlorophyll and epidermal flavonoids
Dear Sanaz,
Thank for the info. Is it to multiply the SPAD reading with the value after dividing 99/144? Is this value a factor and can be used for different crops?
No, you cannot use SPAD meter for estimation of chlorophyll content in leaves because it gives us only a realtive measure of greenness and it cannot help us to convert the readings to absloute amount of chlorophyll content.
Well, you can do the conversion as Sanaz said but i thick its better to find the correlation for each plant alone
hello everyone. Namaste to all . I have gone through Sanaz Afshari Behbahanizadeh mam suggestion which was excellent. but my doubt is, how can we convert chlorophyll a, chlorophyll b, carbohydrate, phenol, reducing sugar and nonreducing sugar vale (mg/g) to (microgram/sq cm). pls suggest. its very much essential to me. waiting for your kind reply
- Badges
- Science topic
- Similar topics
- Agricultural Science
- Agronomy