Effect of Cutting Type, Collection Time of Cutting, Plant Sex, Stem Wounding Method and Presence or Absence of Leaves on Rooting and Growth of Jojoba Shrub Cuttings

Abstract

A series of six experiments were conducted with an objective of studying the effect of cutting type, collection time of cutting, plant sex, presence or absence of leaves and wounding method on the rooting and growth of jojoba shrub cuttings during 2016-2017 in the Jojoba Naturals Company greenhouses at Sana’a, Yemen. The cuttings were collected, prepared and planted under the transparent plastic tunnel. Perlite medium and automatic mist irrigation were used in the propagation beds. Relative humidity was between 80-99% and the temperature range was not more than 40 o C. Different parameters of rooting and growth of rooted cuttings were determined. Semi-hardwood and softwood cuttings recorded higher rooting percentages (77.77% & 82.22%) respectively than hardwood cuttings (26.11%). The cuttings collected in the spring season gave the greatest value of rooting compared to those collected in autumn and winter season. The presence of leaves on the cuttings within rooting time affected significantly the rooting percentage in comparison with the cuttings without leaves. However, the plant sex and wounding method did not differ significantly in respect of the rooting percentage of semi-hardwood cuttings. By this investigation, an efficient protocol including collection time of cuttings, rooting medium, plant hormone with its concentration, cutting type and rooting conditions was standardized. Thus, jojoba rooted cuttings would be produced in commercial quantities. As rooting success ratio of cuttings exceeds more than 90%.