Effect of Early Upward Tapping on Rubber Productivity of Clone PB 260 of the High Metabolic Activity Class
Kouakou N’guessan Kan Pulchérie *
Université Nangui Abrogoua, UFR Sciences de la Nature, Laboratoire de Biologie et Amélioration des Productions Végétales, 01 BP 801 Abidjan 01, Côte d’Ivoire.
Diarrassouba Moussa
Ecole Nationale Supérieure d’Abidjan, Physiologie Végétales, 08 BP 10 Abidjan 08, Côte d’Ivoire.
Essehi Jean Lopez
CNRA (Centre National de Recherche Agronomique), Station de Recherche de Bimbresso, 01 BP 1536 Abidjan 01, Cote d’Ivoire.
Moro Affia Perpétue
Université Nangui Abrogoua, UFR Sciences de la Nature, Laboratoire de Biologie et Amélioration des Productions Végétales, 01 BP 801 Abidjan 01, Côte d’Ivoire.
Konan Kan Ulrich Urbain
Institut National Polytechnique Houphouët Boigny (INPHB) de Yamoussoukro, Ecole Doctorale. BP 1093 Yamoussoukro, Côte d’Ivoire.
Kouakou Tanoh Hilaire
Université Nangui Abrogoua, UFR Sciences de la Nature, Laboratoire de Biologie et Amélioration des Productions Végétales, 01 BP 801 Abidjan 01, Côte d’Ivoire.
Obouayeba Samuel
CNRA (Centre National de Recherche Agronomique), Station de Recherche de Bimbresso, 01 BP 1536 Abidjan 01, Cote d’Ivoire.
*Author to whom correspondence should be addressed.
Abstract
In order to evaluate the effect of early upward tapping on rubber productivity of rubber trees and to determine its proportion relative to downward tapping, a study was conducted at SAPH Divo on the PB 260 clone of the fast metabolic activity class. The experimental set-up was a Fisher block with seven treatments and three replications. Tapping was carried out in d3 with 6 stimulations. Three upward tapping times at 6, 7 and 8 years, each coupled with two concentrations of the stimulating paste 2.5 and 5% of Ethephon and a downwardly tapped control stimulated with 5% of Ethephon were tested. The data collected were for rubber production, isodiametric growth, tapping panel dryness susceptibility and tree physiological profile. The results showed that the different treatments tapped in upward at 6, 7 and 8 years of age significantly improved the productivity of the PB 260 clone relative to the control by downward for nine years. All treatments combined, rubber productivity (4723 kg.ha-1.yr-1) and radial vegetative growth (3.8 cm.yr-1) were good. The gain in rubber productivity of the early upward tapping compared to the downward tapping was 42%. The tapping panel dryness rate was low at 2.6% and the physiological profile of the trees was well balanced. Our results suggest that PB 260, and therefore metabolically active clones, can be tapped in early upward tapping, especially at 6 years of age.
Keywords: Early, productivity, upward tapping