1 - Acacia Seyal Gums in Sudan: Ecology and Economic Contribution

Abstract

Historically, Acacia seyal gum in the Sudan ranks as the second most important gum product after Acacia senegal in terms of quantity. It contributed an average of 10% of gum products until 2011, and then the average contribution percentage within the last 4 years (2012–2015) jumped to almost 60%. A. seyal trees’ coverage extend in an area of 36,000 square kilometers (3.6 million ha) in a latitude ranging between 100° and 140°N. The distribution of the A. seyal stand is extensively on the clay soil plains, where average rainfall ranges between 300 and 400 mm. Two infraspecific variants of A. seyal widely distributed in Sudan are separated on the basis of the presence and absence of ant galls and color of the bark. Ant-gall and white-colored bark are the characteristics of the fistula variety, while the bark of the seyal variety is green or red. Despite the significant contribution of A. seyal to the export market in the Sudan, farmers have a slightly poor knowledge of postharvest cultural practices of A. seyal, which include proper methods of storage conditions and gum stacking. Nevertheless, this chapter is trying to review the existing research in the areas of A. seyal ecology, distribution, and pre- and postharvest cultural practices, which include tree husbandry, tapping, gum collection, handling, and storage. Also, physical and chemical properties of A. seyal will be highlighted as well as the contribution of A. seyal gums to the portfolio of exports.