Increase in Carbohydrate Status in the Wood and Bark Tissues of Hevea brasiliensis by Double-cut Alternative Tapping System

Abstract

Starch and total soluble sugar (SS) status in rubber tree were investigated carbohydrate reserve related to tapping system. RRIM 600 clone were studied for three years in Chachoengsao Rubber Research Center (CRRC-RRIT-DOA). Trees were tapped using 1/2S d/2 (control, D/2), 1/2S d/3.ET 2.5%,8/y (D/3) and the DCA system (double-cut alternative tapping system). Bark and wood tissue were collected in October 2002 (period of high rainfall and high latex production) at various positions along trunks and were analyzed using starch enzymatic analysis technique. Together with a higher production of latex, DCA system had higher content in both starch and SS in wood. In bark, SS was also higher in DCA, whereas starch was not different among treatments. According to accumulation of starch on various part of tree, it was found that the starch decreased with height of samples up the trunk. Content in lower part of tree was higher than that in the top or crown part, but there was the decrease of starch in both wood and bark within the bark regeneration area or the area which has been already tapped, confirming the hypothesis that tapping affects the level and distribution pattern of carbohydrate within the trunk.