Prospects for sustainable cocoa farming from the rainfall balance in the last thirty years at Lh-Djiboua and Gh post-pioneer regions, Cte dIvoire

The rainfall disturbances observed in the recent decades in Côte d'Ivoire constitute a constraint for sustainable cocoa production, the mainstay of the Ivorian economy. These disturbances constitute, in addition to the losses of production and those from the quality of the cocoa beans, one of the causes of the high cocoa mortality at the recovery stage in all cocoa production area. The present study, carried out in the Goh and Lôh Djiboua, post-pioneer regions, is a contribution for the searching of solutions to the continuity challenge of the Ivorian cocoa farming in front of the climate change. It aims to analyze not only the evolution and distribution of rainfall, but also to identify the rainfall constraints related to cocoa farming, and to propose possible solutions to ensure the sustainability of cocoa farming in these two regions. The analysis covered the three decades of the period from 1986 to 2015. The rainfall data were collected at the weather stations of the CNRA (Centre National de Recherche Agronomique) based both on Divo and Gagnoa. The study of the two rainfall data series using the rainfall index showed that the current climate of the two regions is characterized by a predominance of dry periods at Divo and the wet one in Gagnoa. Also, 40 to 90% of the 30-years recorded less than 700 mm of rain during the main rainy season both in the two regions. In addition the beginning of the rainy season in the two regions is between the 1st and 2nd 10 days of March in both regions, while in practice the planting of cacao is usually made in May or June. To note this variability, the technical itineraries for all regions must to be regionalized to enable cocoa to exhibit its potentialities in its new production environment.