INFLUENCE OF PLANTING DATES AND SOME CHEMICAL SUBSTANCES ON ROOTING OF PHYTOLACCA DIOICA

The present study was carried out under plastic house conditions at the nursery of Zohria garden, Hort. Res. Inst., ARC, Cairo, Egypt throughout the two successive seasons of 2015 and 2016 to reveal the effect of planting dates (winter, spring, summer and autumn), some rooting promoters at different concentrations i.e. IBA, NAA, 2,4-D, catechol, cinnamic acid and tryptophan (alone or in combination) and their interactions on rooting of hard-to-root ornamental tree Phytolacca dioica.Results revealed thatplanting in spring increased rooting percentage (%) and root length (cm) in both seasons to the highest values. Treating the cuttings with IBA at 4000 ppm + NAA at 4000 ppm formulation resulted in the highest rooting percentage (%) in both seasons. Although there was no clear trend that could be observed from the obtained results, planting cuttings in either spring or autumn in addition to treating with IBA at 4000 ppm + NAA at 4000 ppm formulation increased rooting percentage (%) to the highest values.In conclusion, to achieve a successful vegetative propagation and to induce rooting on cuttings it is recommended to plant the cuttings in either spring or autumn in addition to treating with IBA at 4000 ppm + NAA at 4000 ppm formulation.