Abstract
Weeds are among the important pests of agricultural and nutritional crops causing major yield loss, ranged between 10% to 98% of total crop yield, which may vary from crop to other or region to other in the same crop. This loss in crop yield results when parasitic weeds attach themselves to another plant, their ‘host', and draw nutrients from it causing huge damage to the host crop and consequently huge economic loss. Orobanche spp., Striga spp. and Cuscuta spp. are the most common parasitic agricultural weeds with economic importance in many world parts. Applying control methods selective enough for killing these parasitic weeds without causing crop damage is as difficult as the application of chemical herbicides which causing soil and water contamination and adverse effects to beneficial organisms and hence loss in the nutritional benefits of the cultivated crop. In some cases, chemical compounds which resulting from herbicide degradation process may continue to be significantly toxic to health and environment. A review was made to highlight research conducted yet concerning important alternative methods to herbicides, such as biological control; natural products; agricultural practices and cropping systems, for controlling parasitic weeds and their management in nutritional crops.