Impact of the variation of climatic parameters on rainfed rice production in the Haut-Sassandra region (Central-Western Côte d'Ivoire)

In Cote d'Ivoire rice cultivation is practiced in rainy conditions and remains sensitive to climatic uncertainties. This study is conducted to analyze the variation of climatic parameters and their impact on rice production in the high Sassandra region. The daily climatic parameters (rainfall and temperature) recorded over the period from 1976 to 2005 and the agronomic characteristics of two rice varieties (NERICA 1 and IDSA 85) were used for yield simulation using SARRA-H model. The results showed that the rainy season generally begins in March while instability is observed at the end of the rainy season (between 15 July and 9 October). Overall, the annual rainfall recorded remains potentially appropriate to meet rice water requirements. However, rice cycle shortens when the temperature rises; besides it lengthens when the photoperiod is high. Regardless of sowing date, the total requirements are essentially the same for both rice species. The best yields, 17,161 kg/ha for NERICA1 and 20,048 kg/ha for IDSA85 are obtained when sowing on 5th April. On the other hand, the date of 15th March gives the lowest yields. These results constitute a significant contribution in the redefinition of the rice agricultural calendar in the high Sassandra region.