I just read that quote on Co2.
I feel dumber for it.
Not that the the information wasn't smart.
But that I didn't understand it.
At all.
And now I feel dumber.
Huh?
the paper was done for the pharmaceutical industry to determine the best parameters for "commercial" indoor cultivation. i think that mold, pest and diseases were considered.
the vpd question is divided into two opposed schools of thought. the first is the "feed forward" theory, whose proponents think that stomatal conductance Gs is directly and linearly driven by the VPD.
the second group believes that Gs is driven by not only VPD but also co2 assimilation and the ratio of internal co2 to ambient. this is the "feed back" theory.
both groups have done numerous experiments that produce data that supports their arguments but so far as i know, no one has absolutely proven anything.
the graphs in dr el sohly's paper clearly show a higher water use efficiency and a higher rate of photosynthesis under conditions of elevated co2 even with a lower rh.
have a nice fucking day!