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Hi there, i did'nt wanted to re-do a topic that would have been really similar as this one. I hope i will be enough precise to get an answer to my question. Here it is: I am currently trying to assess the photosynthetic activity of some strawberry and lettuce plants in order to compair it. Those plants will not be conducted Under the same cultural practices...in a way. To be totaly precise they are going to grow in an aeroponic urban farm column on a Paris rooftop (yes i am French...excuse my poor English…). I want to assess if their is a significant difference of photosynthetic activity between the plants at the top of the column and the ones at the Bottom. I know that it would be much more precise and efficient to use a fluorometer for it, but the company i am working for can't afford it. So their is my precise question: In what extent the infragram and so the NDVI measure is precise when we talk about measuring photosynthetic activity? Do you think that it will be enough to reveal differences between my plants knowing the really slight environment differences between them?
I hope that my question is enough clear and even more that you can give me an answer ^^.
Merci beaucoup!
If photos are taken of plants in two treatments (top and bottom) with the same camera settings (all manual control) under the exact same lighting conditions it is possible to discern subtle differences in plant health from the numerical values of NDVI (not the colors of NDVI images).
A calibration routine using targets of known spectral reflectivity in each photo can relax the requirement that the color and intensity of light be identical for all photos.
Close-up photos of individual leaves will be best so the angle of the leaf and the angle of light can be controlled (identical in both treatments) and an average NDVI value can be computed from replicate areas of each replicate leaf on each replicate plant.
Capturing the required NIR and visible images with separate dedicated cameras will provide better results than using a single camera (one or the other channel [NIR, visible] will be cross-contaminated).
Yes of course!!!
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Hi there, i did'nt wanted to re-do a topic that would have been really similar as this one. I hope i will be enough precise to get an answer to my question. Here it is: I am currently trying to assess the photosynthetic activity of some strawberry and lettuce plants in order to compair it. Those plants will not be conducted Under the same cultural practices...in a way. To be totaly precise they are going to grow in an aeroponic urban farm column on a Paris rooftop (yes i am French...excuse my poor English…). I want to assess if their is a significant difference of photosynthetic activity between the plants at the top of the column and the ones at the Bottom. I know that it would be much more precise and efficient to use a fluorometer for it, but the company i am working for can't afford it. So their is my precise question: In what extent the infragram and so the NDVI measure is precise when we talk about measuring photosynthetic activity? Do you think that it will be enough to reveal differences between my plants knowing the really slight environment differences between them?
I hope that my question is enough clear and even more that you can give me an answer ^^. Merci beaucoup!
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Hi! It could be interesting to try measuring the berries themselves as well; check out the spectrometer work by this group for a reference! #webvalley
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If photos are taken of plants in two treatments (top and bottom) with the same camera settings (all manual control) under the exact same lighting conditions it is possible to discern subtle differences in plant health from the numerical values of NDVI (not the colors of NDVI images).
A calibration routine using targets of known spectral reflectivity in each photo can relax the requirement that the color and intensity of light be identical for all photos.
Close-up photos of individual leaves will be best so the angle of the leaf and the angle of light can be controlled (identical in both treatments) and an average NDVI value can be computed from replicate areas of each replicate leaf on each replicate plant.
Capturing the required NIR and visible images with separate dedicated cameras will provide better results than using a single camera (one or the other channel [NIR, visible] will be cross-contaminated).
None of the above is easy to achieve.
Chris
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