alt Hacker NewsCapillary action is subject to the same limits as suction at the top. Capillary action can't increase the water pressure at the bottom of the tree.
If you put a straight thin capillary tube upright in water so it sucks up water from the bottom, no matter how thin, it can't draw water up above ~10m of water level.
you have an incorrect model, transpiration is capillary action and evaporation from mesenchyme
xylem is not a straw, is no where near the diameter of a straw, and its[transpiration] is not about increased pressure its about decrease.
psi values at the apical mesenchyme are around -100 to -150 megapascals dependent on species and relative humidity at the stoma.
physics and biology although intertrined are not the same catechisms, heres a link toward most of m.j. canny's work.
https://www.researchgate.net/scientific-contributions/M-J-Ca...
here is is a basic scheme of things
Water Movement in Xylem:
https://oercommons.org/courseware/lesson/87595/student-old/?...
Xylem:
https://en.wikipedia.org/wiki/Xylem
Hydrogen bond:
https://en.wikipedia.org/wiki/Hydrogen_bond