i Effects of 2, 4-D and Nitrogen on Striga hermonthica (Del.) Benth. Incidence, Sorghum (Sorghum bicolor (L.) Moench) Growth and Parasitism By Awadallah Belal Dafaallah Belal B.Sc. (Honours) Crop Protection Faculty of Agricultural Sciences University of Gezira (2001) A Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science in Crop Protection (Weed Science) Department of Crop Protection Faculty of Agricultural Sciences University of Gezira Main Supervisor : Co-Supervisor : Prof. Abdalla Mohamed Hamdoun Prof. Abd Algabar Eltayeb Babiker September, 2006