Antitranspirant

Antitranspirants are compounds applied to the leaves of plants to reduce transpiration. They are used on Christmas trees, on cut flowers, on newly transplanted shrubs, and in other applications to preserve and protect plants from drying out too quickly. They have also been used to protect leaves from salt burn and fungal diseases^{[citation needed]}.

Antitranspirants are of two types:

Metabolic inhibitors

These reduce the stomatal opening and increase the leaf resistance to water vapour diffusion without affecting carbon dioxide uptake. Examples include phenylmercuric acetate, abscisic acid (ABA), and aspirin.

Film-forming antitranspirants

These form a colorless film on the leaf surface that allows diffusion of gases but not of water vapour. Examples include silicone oil and waxes.