MORPHOLOGICAL,ANATOMICAL AND BIOCHEMICAL EFFECTS OF PROPACHLOR ON SEEDLING GROWTH*

Summary. The root and shoot growth of oat (Avena saliva L.) and squash (Cucurbita maxima Duchesne) was reduced in proportion to propachlor concentration. Corn (Zea mays L.) root growth was inhibited only by concentrations of 16 ppm and higher. Cell division in onion (Allium cepa L.) root tips was reduced by propachlor and totally inhibited by 16 ppm. Auxin-induced cell elongation of oat coleoptiles was inhibited in proportion to propachlor concentration. Propachlor treatment prevented the normal senescence of squash cotyledons by inhibiting the autolysis of proteinaceous and lipid reserves. Effets morphologiques, anatomiques et biochimiques du propachlore sur la croissance des plantules Riisumi.