i could not find the study anymore.
its not science, just grow weed easy but could imagine its based on the study.
by Nebula Haze Are your leaves all tipped up, "praying" to the sun gods? I used this think this was the sign of a healthy, fast-growing marijuana plant, but it's actually a sign of stress! Pointed up leaves are sometimes the first sign your cannabis plant is getting too much light. You also...
www.growweedeasy.com
i think whats described is only true when our plants are in flower and there are more factors influecing it, like mentioned VPD, stimulants etc.
i think little praying is a good sign, if it goes over certain angle its unatural for me.
the 730nm as only light source at night was a eye opener, leaves poinitng up like crazy while the plant should have slept.