Productivity of Gum tartar in Southern Kordofan State. Sudan

The overall objective of the present research was to develop productivity equations of gum karaya (tartar gum) from Sterculia spp. as related to measurable growth parameters (height, diameter and crown height). The total area for this study was 75 hectare representing three locations each covering 25 hectare (500 m x 500 m). In each site, 50 sample plots were randomly chosen using random tables and GPS. The closest three trees to the centre of the each sample plot were selected for tapping by using an axe. The targeted trees for tapping were 116 trees from ALmazlagan area, 141 and 135 trees from bottom and top of Gabal Alahmar, respectively. Diameter at breast height (dbh), tree height (h) and crown height (ch) were measured for each tree and 8 gum collections were carried out for the sample trees starting from October 2006 to May 2007. Gum from each tree was collected, weighed and recorded for each selected sample tree. The data were analyzed using excel (spread sheet), SAS and JMP programs. Linear regression was used between measurable parameters with monthly gum picking and total gum production. The results for the three locations showed that there were significant differences between measurable parameters and monthly gum picking and crown height. In site Π; there was a significant difference in monthly gum picking and total gum production between diameter at breast height and average tree height. A total of 84 equations were developed for the three locations. The most important equations were relationships between height and diameter at breast height, crown height and diameter at breast height and crown height and height. The most important equations relating gum production and measurable parameters were relationships between total vi production and diameter at breast height, total production and crown height and total production and height The study showed that the maximum gum production is on the mountain top followed by the mountain bottom with the least production in the plateau. The hottest months of the year (March, April and May) yielded the best gum quality and quantit