Effect of Weeds on Calcies Yeild of Hibiscus Sabdariffa L in Traditional Agricultural Sector of Sudan

Weeds play an important role in the proper stand establishment of the growing crop, which ultimately affect the productivity and quality at the end of the growing season. Hand hoeing is still by far the most widely practiced cultural weed control technique in field crop production throughout the traditional agricultural sector in Sudan, because of the prohibitive costs of herbicides and fear of toxic residue coupled with the lack of knowledge about their use. Fields studies were conducted at North Kordofan state, Sudan, on naturally infested fields within the same area, using three similar fields during 2007/2008 rainy season, to determine optimal weeding frequency for weeding management in two widely used cultivated varieties of Hibiscus sabdariffa L, (Elrahad and Elfashir). The majority of weeds in site were the broad leaves (dicotyledons), while grasses (monocotyledons) found in a lesser density. The dominant weed floras were Alhuskaneet (Cenchrus biflorus L), Sheilini (Zornia glochidiata L) and Alraba (Trienemara pentanture L). Weeds reduced yield of the crop by about 75 % compared to weeding twice during the season.