Two main types of phosphorus-containing compound are currently under invest
igation as potential fungicides: (a) esters of phosphoric, phosphorothioic,
phosphorodithoic, or alkyl-phosphonic acids, including examples containing
terpenoid or heterocyclic structures, and (b) aminophosphonic or aminophos
phinic acids and their derivatives. The latter types are especially attract
ive environmentally but none has yet been commercialised.