Rooting Ability of Irvingia wombolu Juvenile Stem Cuttings under Different Growth Regulators in a Mist Propagation System

Oluseye Faith Oyedeji; G. A. Adebusuyi; M. O. Nola; O. A. Iroko; M. O. Majolagbe; N. B. Obekpa

doi:10.58709/niujcjg.v12i2.2657

Oluseye Faith Oyedeji Forestry Research Institute of Nigeria, P.M.B. 5054, Jericho Forest Hill, Ibadan, Nigeria
G. A. Adebusuyi Forestry Research Institute of Nigeria, Jericho Hill, Ibadan, Nigeria
M. O. Nola Forestry Research Institute of Nigeria, Jericho Hill, Ibadan, Nigeria
O. A. Iroko Forestry Research Institute of Nigeria, Jericho Hill, Ibadan, Nigeria
M. O. Majolagbe
N. B. Obekpa Forestry Research Institute of Nigeria, Jericho Hill, Ibadan, Nigeria

DOI: https://doi.org/10.58709/niujcjg.v12i2.2657

Abstract

The domestication and large-scale propagation of Irvingia wombolu are constrained by poor natural regeneration and seed recalcitrance, making vegetative propagation a viable alternative for its conservation and cultivation. This study evaluated the rooting ability of juvenile stem cuttings treated with different plant growth regulators under a mist propagation system at the Tree Physiology Nursery, SFM Department, Forestry Research Institute of Nigeria (FRIN), Ibadan. A total of 150 juvenile double-node stem cuttings obtained from six-month-old seedlings were treated with IBA, NAA and GA at concentrations of 200, 250, and 300 ppm using the quick-dip method. Treated cuttings were planted in sterilized river sand and arranged in a Completely Randomized Design with three replicates and a control. Survival, rooting, callus formation, and mortality were assessed after three months and analyzed using descriptive statistics and ANOVA. Significant variation was observed among hormone treatments. NAA at 200 and 250 ppm recorded the highest survival (91.67%), while GA treatments and the control showed the lowest survival (66.67%). Overall, NAA achieved the highest mean survival (86.11%), whereas IBA produced the greatest rooting percentage (50.11%), outperforming NAA (19.44%), GA (27.78%), and the control (22.22%). NAA also induced the highest callus formation (50.00%), while GA resulted in the greatest mortality (30.56%). The findings indicate that although NAA enhances cutting survival, IBA is more effective for adventitious root induction, particularly at 200–250 ppm. The study recommends IBA as the preferred growth regulator for the vegetative propagation of I. wombolu to support domestication, conservation, and sustainable plantation establishment.

Keywords: Irvingia wombolu, juvenile stem cuttings, rooting hormones, Indole-3-butyric acid, naphthalene acetic acid, mist propagator, vegetative propagation