ABSTRACT
When it is remembered that Hevea brasiliensis contains an average of 60 to 70% water it is easy to see that the availability of water must a priori form a potential limiting factor for production. The reasons for this astonishing paradox are probably to be found in the colloid nature of latex and in its flow mechanisms. The dilution reaction and the kinetics of flow have been studied by a fairly large number of researchers. The smaller yields of late tapping has been accepted to such an extent that during a certain period in Thailand, tapping of Hevea was carried out during the night. The direct relationship between wind speed and relative transpiration has been demonstrated in Hevea. In conclusion, a high osmoticum content in latex and sufficient available water to approach maximum turgor pressure in the laticiferous tissue are the conditions required for good expulsion of latex.
