TITLE:
Effect of Mode of Auxin Application on Rooting and Bud Break of Shea Tree (Vitellaria paradoxa) Cuttings
AUTHORS:
Moses Okao, Lawrence Ogwal, Gloria Mutoni, Samuel Oyuko Alip, John Bosco Lamoris Okullo, Clement Akais Okia
KEYWORDS:
IBA Mode of Application, Shea Tree, Extended Soak Method, Bud Break
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.7 No.15,
November
9,
2016
ABSTRACT: Vegetative propagation by stem cutting is an important technique applied for agricultural
production where rooting success is one of the major aspects. A study to assess
the effects of mode of application of rooting hormones (IBA) on adventitious
root formation of V. paradoxa stem cuttings was conducted. Accordingly, four application
methods were investigated in a 4 × 3 factorial experiment using a Completely
Randomized Design (CRD). The application methods were: 24-hour extended
soak, foliar spraying, basal quick dip and delayed IBA application method. Thus, the
parameters used to determine rooting success were mean root length and root number.
The effect of these application methods on occurrence of bud break was also
considered. On the whole, root length was observed to be a function of IBA concentration,
whereby root length increased significantly (P ≤ 0.05) with an increment in
IBA concentration. Stem cuttings subjected to 24-h extended soak at 100 ppm rooted
best (59.5% ± 8.33%), where as foliar sprayed stem cuttings exhibited the worst
rooting success (11.9 ± 3.06 - 23.8% ± 4.16%). Bud break appeared to decrease with
increasing IBA concentration and delaying IBA application enhanced rooting percentage
of the quick dip method by 7.1%, 9.5% and 11.9% at 2500 ppm, 3500 ppm
and 4500 ppm, respectively. The extended soak method of IBA application at 80 ppm
shows potential for large scale production of V. paradoxa through stem cuttings.