The region of São Paulo Occidental Plateau is well known for its part as a major producer of natural rubber. In order to obtain information about adaptation of rubber tree clones [Hevea brasiliensis (Wildd. ex. Adr. de Juss) Müell. Arg.] RRIM 600, RRIM 701, IAN 873, PB 235 and GT 1, in the city of São José do Rio Preto some biologic characteristics were evaluated. Analysis were performed by monitoring gas exchanges and by measuring vegetative development, during the 18 months after engraft on the Tjir 16 clonal rootstocks. The height of RRIM 600 reached a mean of 3,74 m, and the diameter of the stem of IAN 873 and RRIM 600 reached the mean of 2,50 cm. Clone PB 235 presented the lowest relative growth during the period. During the wet period, the values of the gas exchange did not show significant variation among the clones; the mean value of photosynthetic rates was 9,45 mmol.m-2.s-1; of transpiration rates was 3,84 mmol.m-2 s-1, and of stomatic conductance was 0,096 mol.m-2 s-1. Differences in values of gas exchanges were observed only during the dry period, with notably large reduction for clone PB 235. The characteristics analyzed lead to the conclusion that performances of clones IAN 873 and RRIM 600 were superior, and that of clone PB 235 were inferior.
adaptation; gas exchanges; Hevea brasiliensis; grafting
