This work aimed to compare some aspects of the leaf-gas exchange and water balance of two field grown cultivars (Fx 3864 e RRIM 600) of the rubber tree. Measurements were carried out for two months between the wet and dry seasons of 2001 and 2002. Integrated values of gas exchange showed a decrease in photosynthesis (32% and 22%), transpiration (44% and 38%), and stomatal conductance (29% and 17%) for RRIM 600 and Fx 3864, respectively. Osmotic potential decreased by 41% for RRIM 600, and by 36% for Fx 3864. The results suggest that the performance of Fx 3864 was similar to that of RRIM 600 throughout the year at the juvenile stage studied.
gas exchange; Hevea brasiliensis; water and osmotic potentials
