Abscisic-acid content of xylem sap

Abstract
Abscisic acid (ABA) has been identified by gas chromatography in xylem sap of the woody species apple, peach, willow, sugar maple, Tecomaria capensis and Actinidia chinensis. The amounts of ABA present in each species are markedly different, varying from 9 to over 1000 ng/100 ml of sap.