Abstract. Roots and shoots of corn seedlings (Zea inays L. var. Dixie 18) germinated in trifluralin (a,a,a-trifluoro-2,6-dinitro-N,N-dipropvl-p-toluidine) Certain growth regulating chemicals such as 'Tordon (4-amino-3,5,6-trichlo.ropi'colinic acid) and 2,4-D prommote radlial enlargement of iplant segments and also affect nucleic acid metabolism (11,12,17). The carbamates also promote radial enlargement of root tissue and are believed to disrupt spindle formiation in cell division (7). Standifer et al. (28) and Talbert (29) found 'that swelling of the root terminalts was the iobvious morphological effect caused by the herbicide trifluralin (a, a, a-trifluoro-2, 6-dini.tro-N, N-dipropyl-p-tolluidine). Talber't (29)