Evolution of the Rate of Live and Tapped Trees of Hevea brasiliensis Clones, Muell. Arg. the First 15 Years of Plantation Establishment
Diarrassouba Moussa *
Ecole Nationale Supérieure d’Abidjan, Physiologie Végétales, 08 BP-10 Abidjan 08, Côte d’Ivoire.
Soumahin Eric Francis
UFR Agroforesterie, Université Jean Lorougnon, Laboratoire Amélioration de la Production, Agricole, BP-150 Daloa, Côte d’Ivoire.
Konan Djézou
CNRA (Centre National de Recherche Agronomique), Station de Recherche de Bimbresso, 01 BP-1536 Abidjan 01, Cote d’Ivoire.
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.
Moro Affia Perpetue
Université Nangui Abrogoua, UFR Sciences de la Nature, Laboratoire de Biologie et Amélioration des Productions Végétales, 01 BP 801 Abidjan 01, Côte d’Ivoire.
Koffi Antoine
UFR Agroforesterie, Université Jean Lorougnon, Laboratoire Amélioration de la Production, Agricole, BP-150 Daloa, 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
The density of tapped rubber trees in a plantation is a determining parameter of its productivity. It is related to the number of trees planted per hectare, the evolution of which can be influenced by several factors that act on the trees from the year of establishment to the time of tapping. To this end, a study to determine the evolution of the rate of live trees and tapped trees of eight rubber clones during the first fifteen years of establishment was carried out in southwestern Côte d'Ivoire. At opening, rubber trees planted at 510 trees/ha (7 m x 2.80 m) were bled in a descending half-spiral at different tapping and stimulation frequencies. The experimental design was a Fisher block design with 6 treatments (d2, d3/4y, d4/4y, d4/8y, d5/8y, d6/10y) and 3 replications. The results revealed that the rate of live trees and tapped trees was not influenced by either clone or latex harvesting treatment. The rate of live trees decreased progressively from the immature phase of the plantation (94.71 ± 1.34%) to the end of the downward tapping (91.55 ± 0.67%). The rate of tapped trees increases from the time of planting (69.51 ± 8.03%), over the years (92.00 ± 1.39%) until it equals the rate of live trees (92.00 ± 1.08%) before gradually decreasing to 88 ± 3.78%. It should be noted that the factors influencing the evolution of the rates of live and taped trees caused less damage to the rubber trees. And this influence is not dependent on clone, metabolic activity class and latex harvesting system.
Keywords: Density of trees, live trees, tapped trees, immature period, Hevea brasiliensis.