Evaluation of Dry Bean Yield Response to El Nino Southern Oscillation (ENSO) in Haiti with the SIMPLE model. Case study : Duvier

Résumé

Dry beans are the sixth most grown crop in Haiti and represent an excellent and affordable source of protein for low-income families. However, according to a study conducted by Michigan State University in 2010, an annual decrease of 1.1% is observed in the yield of dry beans cultivated in Haiti during the decade 1994-2004. In this study, the potential impact of the annual climate cycle known as El Niño- Southern Oscillation (ENSO) on dry beans grown at Duvier, in Haiti, was investigated. The SIMPLE crop model was used to simulate yields for 37 years of weather data and three main growing seasons: November, April, and July. The ANOVA of the model simulated yields showed there were no significant dry bean yield responses to ENSO phases during the November and April seasons. However, in the case of dry beans planted in July, yields were significantly lower in El Niño years than La Niña and Neutral years. A plausible explanation for this was that a more complicated climate pattern generally dominates July seasons. Known as the mid-summer drought, since the Caribbean low-level jet peaks during that time, ENSO phases tend to be amplified during this season, as are its effects on bean yield in the study region. Simulation results also showed that sowing early during the November season leads to a 60% probability for above-average yields. Whereas, planting late during the other two seasons was more beneficial with a chance of up to 60% to result in higher yields.