We still dont know the perfect spectrum for photosynthesis and evidence points to this changing when intensity is altered.
Studies show green light to be the most usefull and absorbed when red and blue is present but the opposite when on its own.
You often here academic institutions state that ppfd and par are but a small part of the whole picture.
Trying to optimise the light spectrum has never worked, increasing the light spectrum has worked.
For one type of light many measures can give usefull ppfd comparisons but over two different types very little accuracy can be gained in relation to photosynthesis efficiency.
Ppfd should come with a disclaimer that it is by no means accurate, possibly we try to go to far in quantifying light and photosynthesis.
This is one of the mistakes leds have and still make, many years of ommiting spectrum for this false efficiency.
At the moment there is no answer back, pretty rude but i am picking on one of their main facts. Reps hate me as many dont grow and ppfd must seem like the golden ratio to them.
Now on the flip side i turn to hps and see that actually it has quite the range of spectrum, a lot of these ppfd considerations are reasonably satisfied. Who would have thought led growers with all their wisdom would actually do hps a favour here.
I have no idea why we hide from the facts, plant spectrum and light in part is a mystery even to the top academics, why act like we know somthing they dont.
