Influence of Shea tree (Vitellaria paradoxa) on maize and soybean production.

Vitellaria paradoxa provides many benefits to farmers within the Shea belt. However, increased threats to it necessitate its conservation, and one common approach is the practice of agroforestry. A number of studies have shown that Shea tree has influence on crop production, and yet, some of these studies were done using single season experiments or bioassays using mature Shea tree components. In this study, the seasonal influence of young and mature Shea trees on Maize and Soybean yields was investigated using field experiments in Otuke district of northern Uganda, where, Shea tree parklands are dominant and Maize and Soybean are used for food security and income. Our results show that there are differential responses of maize and soybean yield to rainy seasons and physiological variations of Vitellaria paradoxa with age. We find yield reduction for maize more pronounced than yield reduction for soybeans under different Shea age (Mature and Young) for two rainy seasons. We attribute the variance to the differential maize and soybean responses to Vitellaria paradoxa shading and its differential allelopathic inhibition of these crops. We recommend that Soybeans should be preferred to maize when planting under Shea canopy.