Comparison of Methods of Dry Rubber Content Determination and Correlation between Dry Rubber Content and Biochemical Compositions and Plant Nutrients in Rubber Latex

Abstract

Currrntly, dry rubber content (DRC) is considered as an important factor in rubber latex’s trading, and measuring DRC by each method can result in different amount of DRC. The objective of this study was conducted to compare DRC from 4 methods namly laboratory (actual DRC) (1), trichloroacetic acid (2), microwave (3), and oven methods (4), Results showed that DRC derived from microwave method was lower than that of laboratory method. However was high positive correlation between DRC determined by laboratory and microwave methods ( r = 0.999), and the actual DRC (y) could be predicted from DRC determined by microwave method (x) using an equation showing the relationship between the two methods (y = 1.205x5.220, R2 = 0.998). The correlation between DRC and biochemical compositions and plant nutrients in latex showed DRC in immature rubber tree had positively correlated with Pi and negatively correlated with NH+4, K and Mg. In the mature rubber, DRC have negatively correlated with Pi, R-SH, K and Mg. Therefore, the values of plant nutrients and biochemical compositions in latex could be useful to indicate DRC synthesis activity and could be used as a quideline to adjust type and rate of fertilizers and suitable tapping system for rubber trees.