Inquiry into the movement of 18 new crops from their countries of origin through the early Islamic world. Examines the interplay of attitudes, social structure, institutions, infrastructure, scientific progress and economic development and their role in crop diffusion. Argues that the initial decline of Islamic agriculture may have been triggered by the excesses of its period of expansion and that the final blow was dealt to the new crops in the Islamic world by the circumnavigation of Africa and the discovery of the New World, where the crops were grown for export. A source document on economic history of the Muslim people. Based on primary sources Documented.