Vol. 6, Issue 9, Part A (2020)

Abstract
A prospective study of technologies for harvesting the latex of the Hevea brasiliensis clone BPM 24, with moderate metabolism, at the opening, was undertaken for 7 years in the south-west of the Côte d’Ivoire. The rubber trees were planted at a density of 510 trees / ha (7 m x 2.80 m) according to a completely randomized scheme. They were bled using ten different latex harvesting systems. The parameters measured were rubber production, isodiametric trunk growth, physiological profile and sensitivity to dry notching. The results showed that bloodletting, like hormonal stimulation, strongly activates the metabolism of laticifers. They indicated that, tapping at 1.20 m from the ground (descending tapping) gives better results compared to that at 0.70 m (ascending tapping) not preceded by a descending tapping for a minimum delay equivalent to 4 years. The tapping in a half-spiral ascending from the fifth year with a high production and a high rate of dry notching shows signs of the onset of physiological fatigue probably linked to overuse. The different hormonal stimulation strategies had little damage to trunk growth and physiological parameters of trees. To best express and maintain its long-term agronomic potential, the latex harvesting system best suited to the BPM 24 clone, when opened, is S / 2 d4 6d / 7 12 m / 12 ET 2.5% Pa1 (1) 4 / y at 1.20 m from the ground (without gradient). In addition, our results indicate that reverse tapping can be introduced at least as early as the fifth, possibly from the sixth, year of latex harvest.