Efficient latex harvesting technologies at the opening of Hevea brasiliensis moderate metabolism clone GT 1 in Côte d'Ivoire

A study of latex harvesting technologies,appropriate to the opening of tapping of hevea brasiliensis clone gt 1 having moderate metabolism,was undertaken in south eastern côte d'ivoire. rubber trees were planted in 1989 at a density of 510 trees/ha and harvesting was started in 1995. ten different latex harvesting systems were tested and monitored for seven years. the parameters measured were rubber yield,isodiametric growth of the trunk,physiological profile and sensitivity to tapping panel dryness. the results showed that tapping with hormonal stimulation highly activated the metabolism of latex vessels. they also indicated that the tapping opening at the height of 1.20m from the ground level of downward tapping showed high yield than the opening at 0.70m in upward tapping and not followed by downward tapping for a minimum period equivalent to four years. half-spiral upward tapping from the fifth year certainly induces very high yield. however,a high rate of tapping panel dryness and signs of early physiological fatigue were observed,probably due to over-exploitation. the different hormonal stimulation strategies caused little damage on the growth of the trunk and the physiological parameters of the latex. the latex harvesting system which is most suitable for clone gt 1,at opening is s/2 d4 6d/7 12 m/12.et2.5% pa1 (1) 4/y at 1.20m above ground. furthermore,it was indicated that upward tapping could be introduced at least after the fifth year. © copyright malaysian rubber board.