Actually, agroforestry research is in full expansion; nevertheless, there remains uncertainty about the performance of combinations of species in regard to the broad range of possible species associations, as well as the variability of environmental conditions under which agroforestry stand can be develops. In Belgium, pedoclimatical conditions, cultural practices and information available in the literature suggest that light might be the principal tree/crop competitiveness resource in agroforestry context. In most study, responses induced by this shade stress condition converge toward a systematic reduction of crop final yield. However, the behavior of wheat to the shade will be highly dependent on environmental conditions. In fact, in agroforestry system, the tree canopy reduces the incident radiation for crop following a dynamic spatio-temporal pattern, considering tree phenology and sun/shade fluctuation in accordance to the path of the sun during the day. What about in wheat efficiency under a later shade, in Belgium? In Gembloux experimental farm, wheat productivity and development will be monitored over 3 years under artificial shade conditions. An original artificial shade structure has been thought to mimics the light environment observed under hybrid walnut agroforestry tree: periodic fluctuation in radiation transmittance and discontinuous light quantity. The aim of this work will be to evaluate the influence of latter shade, light availability and the efficiency with which she is converted in dried matter on wheat under artificial shade treatment.