Interaction of auxins with growth-retarding, -inhibiting and ethylene-producing chemicals in rooting of cuttings

The growth retarding chemical Cycocel significantly synergized IAA- and IBA-induced rooting of mung bean and IBA-induced rooting of tomato cuttings. In marigold, Cycocel and B-Nine promoted rooting when applied alone but did not synergize auxin-induced root formation. Chlorflurenol, a growth-inhibiting morphactin, antagonized auxin-induced rooting of all three species; inhibition was especially marked in the presence of IBA. The ethylene-producing chemical Amchem promoted rooting of mung bean and marigold cuttings when applied alone. In tomato cuttings, Amchem significantly synergized IAA-induced root formation.