Published online by Cambridge University Press: 12 June 2017
Direction and rate of translocation of sucrose* from urea* 2,4-D* (2,4-dichlorophenoxyacetic acid) and amitrole* (3-amino-l,2,4-triazole) were toward regions of active growth. In oak seedlings translocation was slower than in cotton seedlings. In oak seedlings growing leaves and shoots constitute active sinks toward which tracers move. Sucrose* from urea* translocates freely; 2,4-D* moves less freely because of accumulation enroute; amitrole* is intermediate between these. High humidity induces rapid and extensive uptake of tracers by oak seedlings; the increase over normal transport is mainly in the xylem.