SYNERGISTIC EFFECTS OF PLANT-GROWTH RETARDANTS AND IBA ON THE FORMATION OF ADVENTITIOUS ROOTS IN HYPOCOTYL CUTTINGS OF MUNG BEAN

The synergistic effect of plant growth retardants, such as daminozide, paclobutrazol and triadimefon, and of indole-3-butyric acid (IBA) on the formation of adventitious roots in hypocotyl cuttings of mung bean was studied. The three retardants and IBA all stimulated adventitious root growth, but IBA was the most effective. However, mixtures of the retardants with IBA have proven generally more effective than IBA alo ne in promoting adventitious root formation. When IBA was applied to t he hypocotyls one day after cutting preparation followed by the growth retardant on the second day, there were even more adventitious roots produced than if applied in the reverse order. The effectiveness of th e treatments were in the order, IBA followed by growth retardant, IBA + growth retardant together, and IBA alone.