AbstractThis study was carried out at the Agricultural Experiment Station of King Saud University near Riyadh (26° N, 46° E) during the 1984/85 season to study the effect of shading densities on the agronomic and growth parameters of sugarbeet. Two cultivars were grown under three shading nets with densities of 37, 50 and 70 % in addition to the control (0 % shading = normal sunlight condition).The results indicated that shading affected the growth and the weight of sugarbeet plants and the effects were function of shading density. Root weights were drastically reduced by increasing shading density, whereas top weights were less affected.Increasing shading density resulted in a significant increase in specific leaf area, leaf area ratio while it decreased leaf area index, root weight ration, net assimilation rate and crop growth rate for both cultivars. The interaction between shading densities and sampling dates was significant for most of the studied characters, while that between cultivars and shading densities was significant for root weight and crop growth rates only.