96 The contribution of shea butter (Vitellaria paradoxa C.F. Gaertner) to local livelihoods in Benin(Vitellaria paradoxa)Selective retention of shea has increased its relative density in the fields
to three times that in the savanna (Schreckenberg 1996). Of 63 trees (of all
species) per hectare in the fields, 25 are shea. This compares well with the
figure of 30 to 60 shea trees per hectare recorded slightly to the north-east by
Agbahungba and Depommier (1989) and is double that typically found in Burkina
Faso and Mali (Kater et al. 1992; Gijsbers et al. 1994; Boffa 1995). Well over
half the trees in the fields and fallows are productive as farmers tend to clear
younger trees. As a result, regeneration—which is entirely natural—occurs
primarily in the fallows. The only management intervention is the removal of
unwanted individuals (excess regeneration and trees with consistently poor
yields). As has been described for northern Ghana (Lovett and Haq 2000),
selection by farmers of healthy, productive individuals well suited to the
managed field environment is an indication that the species is in the early
stages of domestication.
Like many indigenous species, shea is renowned for its variable yields from
year to year (Schmidt-Leplaideur 1987; Agbahungba and Depommier 1989).
Women said that out of every three years, they expected one good, one bad
and one average year. No clear relationship between annual yield variation
and environmental factors was recognised by farmers; nor has it been identified
in the literature (Boffa 1999). In addition to variability from year to year,
there is also variability between trees (Ruyssen 1957), which farmers explain
by saying, ‘Trees are like people, some are bad, some are middling, and some
are very good’ (Schreckenberg 1996). Farmers considered 1993 a ‘good’ year,
the average yield being 19.6 kg of fruit per tree, which corresponds to 5 kg of
dried kernels.06SHEA.P65 96 22/12/2004, 11:04