DENSITY AND PHENOTYPIC VARIATIONS OF Vitellaria paradoxa Gaernt C. R IN NIGERIAN GUINEA SAVANNAH

Abstract

The variation in density and among phenotypes of Vitellaria paradoxa (Shea tree) was studied in two ecozones (southern guinea savannah and northern guinea savannah) in the Nigerian guinea savannah. The total density of Shea trees in all sampled sites ranges from 5-42, 8-54 and 35-60 in cultivated, fallow and forest land respectively. In both the northern and southern guinea savannah, large trees (>211cm GBH) of shea were present only in cultivated land. Larger trees were found mostly in southern guinea savannah as shea trees are highly protected because of its high product value (oil). The study showed that there was a variation between the populations, related to the traits measured on the trunk and leaf. Six shapes of the tree (Spherical, Broadly pyramidal, Pyramidal, Oblong, Semi- spherical and Elliptical), different leaf base (round, shortly attenuate, oblique, cuneate), leaf shape (oblong, narrowly elliptical, broadly elliptical, elliptical), leaf margin (entire, undulate, round) and leaf apex (retuse, obtuse, acute, acuminate) were identified. Four bark colours (ash-grey, dark grey, white and black) were also identified. The leaf forms of the entire shea trees sampled were generally oblong. The petiole length, leaf length and leaf width ranged between 16.9-28.6, 20.3- 21 and 4.4-8.1 respectively.