Evaluation and Monitoring of Natural Rubber Technological Properties of Rubber Tree Clones Recommended for Plantation on the Plateau of Sao Paulo State, Brazil

The technological properties from four rubber clones (GT1, PB 235, IAN 873 and RRIM 600) of the Hevea brasiliensis species was studied by the acetone extract percentage, Wallace plasticity (P 0 ), plasticity retention index [PRI (%)] and Mooney viscosity (V R ) and correlated with the climatic conditions. The technological properties were performed in the natural rubber in two consecutive years of tappings (40 tappings) for 4 rubber tree clones. The results have shown highly and significant variations among clones and tappings indicating that these variations should be taken into account. The results of multiple regression analysis have shown that the four studied clones have distinct responses due to the environmental variations, the same for performed technological properties. The average value of PRI found for the PB 235 clone was the lowest probably due to its higher values of acetone extract percentage.