Rescaling of the optimal sowing period for rainfed rice in the Ivorian pre-forest zone

Résumé

Climate change in the pre-forest zone of Cote d'Ivoire has led to a mismatch between cropping periods and new seasons, challenging the sowing periods usually recommended for rainfed rice cultivation in this area. Our study aims to determine the optimal sowing period for two rainfed rice varieties cultivated in this pre-forest zone of the country. The agro-climatic analysis carried out over the period 1980-2017 allowed to determine the optimal dates for sowing rice, which ensures, with the maximum probability, the crop's water satisfaction over its entire cycle. This analysis showed that for an annual probability of success over 80%, the optimal sowing period ranges from March 22 to April 26 for the 120-day average cycle rainfed rice variety and, from March 27 to May 11, for the 100-day short cycle rainfed rice variety. These periods allow a good water supply for the crop's first cycle, but it is not possible to implement a second cycle with the same water supply levels in this area.