American Journal of Plant Sciences, 2013, 4, 1758-1764
http://dx.doi.org/10.4236/ajps.2013.49216 Published Online September 2013 (http://www.scirp.org/journal/ajps)
Asexual Propagation of Sheanut Tree (Vitellaria paradoxa
C.F. Gaertn.) Using a Container Layering Technique
Naalamle Amissah
1*
, Brain Akakpo
1
, Julius Yeboah
2
, Essie Blay
1
1
Department of Crop Science, College of Agriculture and Consumer Sciences, University of Ghana, Accra, Ghana;
2
Cocoa Research
Institute of Ghana (CRIG), Bole, Ghana.
Email:
*
naalamle@gmail.com
Received July 5
th
, 2013; revised August 5
th
, 2013; accepted August 25
th
, 2013
Copyright © 2013 Naalamle Amissah et al. This is an open access article distributed under the Creative Commons Attribution Li-
cense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
In spite of the economic potential of the sheanut tree (Vitellaria paradoxa), its domestication still has not been achieved
due to the long juvenile period of seed propagated plants and the absence of a reliable vegetative propagation method.
Three experiments were conducted by using a modified container layering technique to investigate the effects of season
(rainy and dry season), light treatments (etiolation and natural light) and indole 3-butyric acid (IBA) on root formation
in juvenile and mature sheanut trees. The effect of light treatments on the internal conditions such as level of sugars
(soluble, insoluble and total sugars) and total free phenols in layered sheanut shoots was also considered. Rooting was
generally lower in the mature trees (27.9%) compared to that in juvenile 4 year-old plants (40.9%). Etiolation increased
the levels of total sugars and phenols in shoots of 4-year-old plants and mature fruit bearing trees, but this increase did
not significantly enhance rooting in both the juvenile and mature sheanut trees. The container layering technique holds
promise as a method for the asexual propagation of sheanut planting material. Roots formed using this method looked
healthy and were vertically orientated giving layered shoots a better chance at survival.
Keywords: Etiolation; Container Layering Technique; Indolebutyric Acid; Sheanut Tree
1. Introduction
Vitellaria paradoxa C.F. Gaertn (the sheanut tree) is a
deciduous tree native to Tropical Africa and said to be
indigenous to the Guinea and Sudan Savanna zone [1].
Shea butter, a product of its nut, is the main source of
livelihood in the Northern regions of Ghana with the po-
tential to alleviate rural poverty in these areas [2]. Shea
butter has anti-microbial properties and as such is widely
used locally in herbal medicine preparations as well as in
the pharmaceutical and cosmetic industries [3,4]. Despite
the social and economic importance of the sheanut tree,
its tree populations are in the wild and domestication is
still a challenge due to the absence of a reliable propaga-
tion technique. Propagation from seed, which is the cur-
rent method used, is difficult, as seeds are recalcitrant and
have been found to lose viability shortly after harvest [1].
Where seedlings are produced, they possess a character-
istic strong taproot system and do not transplant well.
Vegetative propagation methods such as stem cuttings
and airlayering have also proved unreliable [5-10]. There
are reports of grafting having been used successfully on
field plants [11]. However, grafting can only be used on
already established fields. There is therefore the need to
develop a reliable asexual propagation technique that
would supply rootstock material to help with the domes-
tication of sheanut trees. This research seeks to combine
the use of practices and pre-treatments that have been
shown to enhance rooting in woody plants in conjunction
with a container layering technique. Practices such as
coppicing or severe pruning of tree crowns [12,13], etio-
lation [14-17], and use of plant growth regulators such as
Gibberellic acid (GA
3
) and Indole butyric acid (IBA) [12]
have been found to enhance rooting of mature difficult-
to-root woody plant species.
The proposed container layering technique is one, in
which layered shoots arising from the juvenile portion of
the plant are rooted while still attached to the parent plant.
Frolich [18] was the first to use this method in the pro-
pagation of avocardo varieties. Subsequently, the techni-
que has been modified and used successfully in the pro-
pagation of oak (Quercus spp.) shoots [17,19-21]. The
objective of this study was to develop a reliable vegeta-
*
Corresponding author.
Copyright © 2013 SciRes. AJPS