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 Cote 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.