Determination of the Influence of Cultural Techniques "Densities and Opening Standardʺ on Agrophysiological Parameters of Clones Pb 260, Irca 111 and Rrim 703
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 BP1536 Abidjan 01, Cote d’Ivoire.
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 BP1536 Abidjan 01, Cote d’Ivoire.
*Author to whom correspondence should be addressed.
Abstract
To find out the effect of cultural techniques on agrophysiological parameters, four combinations ̏planting densities (low density or DF at 350 t/ha, normal density or DN at 510 t/ha) and opening standards (opening at 65cm and opening at 50 cm) ̋ were tested on Hevea brasiliensis clones PB 260, IRCA 111 and RRIM 703. This study was conducted for nine years with a split-plot experimental design of two treatments and two subtreatments repeated three times. The different combinations of treatments and subtreatments tested were low density (DN-50 cm), low density (DN-65 cm), normal density (DF-50 cm), normal density (DF- 65 cm). The parameters evaluated were the production at bleeding and per hectare, the average annual increase in circumference, the rate of tree losses and the rate of trees with dry notches. Production per tree was significantly higher at 350 t/ha and 65 cm opening (DF-65 cm), while per hectare production was higher at 510 t/ha. The girths of the different clones are stronger at DF and at the 65 cm opening. The rate of tree loss and the rate of trees with dry notch were low at the 510 t/ha density and the 65cm opening. The appropriate density and opening standard was "normal density 510 t/ha and opening to circumference 50 cm". The cultivation techniques especially the density and opening standard judiciously applied can participate in the sustainable improvement of rubber productivity of rubber plantations.
Keywords: Planting density, opening standards, production, circumferences, losses, dry notch