Seasonal variation of tapping panel dryness expression in rubber tree Hevea brasiliensis muell. arg. in Cote d’ivoire

Abstract

In rubber tree, Hevea brasiliensis, latex production is affected by tapping panel dryness characterized by non exudation of latex from the panel after tapping. The present study shows the sensitivity level of the more planted clones and the influence of climatic factors on the development of tapping panel dryness in Côte d'Ivoire. The lengths of sick panels were measured and the meteorological summaries carrying on the rainfall and the temperature have been made. Analysis of variance and comparison of the lengths of sick panel in relation to rainfall and temperature have been made. The results showed that Hevea brasiliensis clones have not the same sensitivity to tapping panel dryness. IRC A41, PB 217, AF 261 and RRIM 712 clones are little sensitive; IRCA 130, AVROS 2037, IRCA 209 and GT 1, are fairly sensitive whereas RRIC 100, IRCA 230, PB 254, PB 260 and PB 235 appear enough susceptible to tapping panel dryness. They also showed that the expression of tapping panel dryness varies seasonal way and is positively correlated to the water deficit and to the temperature. The less hot period from July to December corresponds to favorable period of rubber tree to better produce latex in stimulation conditions.

Effets de différentes fréquences annuelles de stimulation éthylénique sur les paramètres agrophysiologiques et de sensibilité à l’encoche sèche d’<i>Hevea brasiliensis</i> au sud-est de la Côte d’Ivoire:Cas des clones PB 235 et PB 260 de la classe ..

“…En effet, il apparaît à la pratique, une utilisation abusive de la stimulation hormonale pour espérer augmenter considérablement la production de caoutchouc. Or, l'application excessive de la stimulation peut provoquer à long terme l'arrêt de l'écoulement du latex des arbres (encoche sèche) et entraîner une chute de la production de caoutchouc Okoma et al, 2011 ;Traoré et al, 2011). En outre, la surstimulation a une incidence négative non seulement sur la production, mais aussi sur la croissance isodiamétrique du tronc et les états physiologique et sanitaire des arbres (Obouayeba et al, 2002 (Anonyme, 1993).…”

Latex quality and yield parameters of Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg. clone PB 260 for different tapping and stimulant application frequencies

“…Agro-climatic conditions Agro-climatic conditions can affect the physiology, growth, and yield of rubber trees (Okoma et al, 2011;Purwaningrum et al, 2016a). A yield increase due to stimulant use is strongly influenced by the environmental conditions of the study site.…”

Latex Micro Diagnosis, Modern Management Tool of Rubber Plantations of Clones With Active or Rapid Metabolism IRCA 18, IRCA 130, PB 235, PB 260 and PB 330

“…This difference in economic interest could be explained by the low sensitivity to the tapping panel dryness syndrome of the clones PB 260 and IRCA 130, or to the faculty of these clones to respond favorably to stimulation. Indeed, tapping panel dryness syndrome, being a clone-dependent tree reaction (Dian et al 1995;Gohet, 1996;Okoma, 2008;Diarassouba, 2013), can contribute to the reduction of the yield of a plantation of up to 30 % (Okoma et al 2011). This is partly responsible for the fact that clone PB 235, which exhibits the highest tapping panel dryness rate, expresses the lowest rubber yield.…”