Vitellaria paradoxa is an indigenous fruit tree of Sudano-Sahelian Africa, it is called shea butter tree. There are two subspecies of V. paradoxa, one of which (V. paradoxa) extends from Senegal eastwards to the Central African Republic whilst the other (V. nilotica) occurs in southern Sudan and Ethiopia, Uganda and northeast Zaire (Boffa, 1999). In natural range, shea butter trees are both economically and ecologically important, they are often the main component of the tree stratum in traditional parkland systems, which are farmlands with scattered trees forming an open permanent over-storey of associated annual crops (Bonkoungou, 1992). As a perennial woody species, that shed its leaves annually, it plays a major role in nutrients recycling (De Bie et al., 1998; Bayala et al., 2006). The litter of shea butter tree was shown to have lower nutrient content when compared with Parkia biglobosa (another common parkland non N₂-fixing leguminous tree), and it was found to decompose at a low rate with time (Bayala et al., 2005), suggesting a more sustainable impact on soil fertility (Bayala et al., 2006).

Furthermore, V. paradoxa is highly valued by farmers, mostly because of its fat containing kernels which are sold both in local and international markets, thereby considerably contributing to wealth creation. The vegetable fat of shea nut is second in importance only to palm oil in Africa (Hall, 1996). The commercialization of shea products represents an important source of income at different parts of the community chain, from community levels, with rural children and women who gather and process nuts, to town dwellers as well as entire countries (Bonkoungou, 1992; Boffa et al., 1996). For instance, shea nut was the third export product of Burkina Faso in the 1980’s (World Bank, 1989). Shea butter tree also provides fruits, medicine, construction materials, fuel wood and carving wood (Hall, 1996). Despite its great contributions to both local and national economies, V. paradoxa remains undomesticated. Shea butter trees parklands result from naturally occurring individual trees that are protected by farmers when clearing their fields, thus creating parkland systems (Boffa et al., 1996). These parklands have been reported to be degrading steadily resulting in decreasing tree density and vegetation cover as well as reduced soil fertility (Gijsbers et al., 1994; De Bie et al., 1998; Ouédraogo, 2006). This trend suggests the need to use artificial regeneration to promote this species in farmer’s fields. Thus, very few studies can be found that have varied nutrients availability to assess their full potential in tree manage-ment (Sanginga et al., 1990; Karanja et al., 1999). Consequently, basic information on nutrient requirements of important indigenous tree species is not readily available, leading to lack of practical fertilizer prescription especially at the nursery stage. The practice of using NPK fertilizers separately is seen as one factor contributing to low fertilization efficiency because it always overlook the advantageous interaction that often occurs among the elements when fertilizers are incur-porated in association into the soil (Teng and Timmer, 1996). Therefore, from a domestication perspective, the evaluation of NPK fertilizer appears to be important as a prerequisite for determining how the fertilizer can be managed to promote rapid growth and development in slow growing tree species.

There is no significant difference in shoot height growth of V. paradoxa at 5% level of probability during the period of study (Table 1). This conforms to the findings of Muhammad et al. (2009) that there were no significant differences among the growth parameters of V. paradoxa assessed within the period of study. This is evident in Figure 1 with shoot height readings close to each others, ranging from 8.49to 10.64 cm.

The results of the investigation showed that application of NPK fertilizer did not have significant effects on the growth of seedlings of V. paradoxa.  There is no evidence however that NPK had any beneficial effects on this species at seedling stage, probably because of low quantity of NPK fertilizer applied. Thus, further studies are needed to address the required quantity of NPK fertilizer for effective growth of V. paradoxa seedlings. The results also showed that application of the fertilizer posed to be limiting factor inhibiting the seedling’s collar diameter. Therefore, from the study reported here and the very limited literature on V. paradoxa, it can be concluded that more effort should be employed by research scientist in determining optimum quantity of mineral fertilizers required to the promote growth of V. paradoxa seedlings in nurseries. 

The author(s) have not declared any conflict of interests.