Stomata closing can be induced by

Solution (By Examveda Team)

P. M. A. stands for Phenyl Mercuric Acetate is an odorless, crystalline powder, which is more often used as an herbicide, antiseptic, catalyst, fungicide and preservative for latex paints.
P. M. A. induces stomatal closure and thus acts as an antitranspirant when used at low concentrations for a short duration.