Rubber cultivation has been handicapped from the outset by the impossibility of obtaining self- rooted clones or rootstock clones. The grafting of clonal buds on not selected rootstock remains at the present time the only method of propagation available for the establishment of plantations. However, this "semi-vegetative" multiplication leads to certain heterogeneity and a reduction in the production of rubber compared to that of the mother tree selected. Fields trials have been conducted in Côte d’Ivoire to assess the relative gain in strength and in rubber production due to the use of self rooted in vitro plantlets of rubber on farm in comparison with conventional mature budded clones. Experimentation was made with trees of clones PR 107, IRCA 18 and RIIM 600 obtained by somatic embryogenesis or microcutting. The results showed a gain in volume of the trunk from 9.93% to 16.83% due to the use of in vitro plantlets. A gain of dry rubber production per tree of 3.5% to 32.35% has also been recorded. The gain in girth and rubber production of in vitro plantlets has been influenced by the metabolic class and the physiological profile of the clone. In light of these results, the use of in vitro plantlet as planting material could be considered to increase the productivity of rubber plantations.
Keywords: Hevea brasiliensis, in vitro plantlet, budded plant, growth, rubber yield