ABSTRACT
J. B. Gomez studied the factors affecting determination of the quantity of laticiferous tissue in Hevea brasiliensis. Indeed, structural characteristics determine, for every tree and at every period of its life, the physical conditions of the laticiferous system by defining the physical potential and also the physical limits. The Rays Total Surface parameter was broken down into two new anatomical characters: upright ray cells surface and procumbent ray cells surface. In the same experiments Narayanan investigated a great number of parameters such as yield and girth, structural characters, and physiological criteria. All the parameters were compared with yield by simple or in multiple correlations calculated by means of linear equations including several parameters. Intraclonal studies in a nursery showed that yield displayed the greatest variability with a coefficient of variation of 60%, the lowest variability was observed for the diameter of latex vessels and sieve tubes. All the criteria described above concern the vertical structure of the bark and are axial criteria.
