Low intensity tapping systems applied to clone PR 107 of Hevea brasiliensis (Muell. Arg.) in South-eastern Côte d'Ivoire: influence of the nature of the exploited bark and the position of tapping panel

Abstract

The cultivation of Hevea brasiliensis, main source of natural rubber, is facing a problem of scarcity and/or high cost of skilled labour. One of the means to remedy this constraint is to reduce the intensity of tapping. This work aims at studying in clone PR 107 of Hevea brasiliensis, in south-eastern Cote d'Ivoire, according to the nature of bark and the orientation of tapping, low intensity tapping systems but highly stimulated (S/4U d3 6d/7 . ET5.0% Pa1(1) 8-10/y(m) and S/2 d6 6d/7 . ET2.5% Pa1(1) 8-10/y(m)) enabling to reduce the need for tappers by 10 and 50% compared to a traditional tapping system (S/2 d3 6d/7 . ET5.0% Ba2(2) 4/y(3m) control). This study was carried out on the basis of agronomic and physiological criteria. The results of 21 years of exploitation have shown that reductions in the intensity of tapping were compensated for partially or totally, in terms of yield, by the strong stimulations without causing damage to the vegetative, physiological and health status of trees. The best low intensity tapping systems can be alternatives to the traditional exploitation system in order to reduce the need for tappers and thus make up for a deficit and/or a high cost of labour. These tapping systems are, on downward tapping on BI, S/2 d6 6d/7 . ET2.5% Pa1(1) 10/y(m); on upward tapping on HO, S/4 U d3 6d/7 . ET5.0% Pa1(1) 10/y(m) and on downward tapping on HO, S/4U d3 6d/7 . ET2.5% Pa1(1) 10/y(m).