TREND ANALYSIS OF CLIMATE CHANGE AND ITS IMPACTS ON CASHEW NUT PRODUCTION (Anacardium occidentale L.) IN BENIN

Abstract

The study aims to analyze the past and future climate trends and their impact on cashew nuts yield in Benin. The linear adjustment with the time series analysis was conducted to assess trends of climatic factors and their effect on nut yields. Future climate has been generated using the downscaling method based from General Circulation Models (GCMs); CCCMA-CGCM3 and CNRM-CM3. A correlation analysis between the climatic data of the last 10 years and the cashew nut yields obtained was performed to assess the effect of each climatic factor. The results indicate that rainfall and temperature are marked by very remarkable inter-annual fluctuations. The last three five-year were significantly warmer than previous. The evolution of the average rainfall and temperature between 1970 and 2015 shows an increasing trend with rates ranging from 0.02% to 24%. The studied GCMs predict a decrease in the amount of rain up to 12% especially in the period from August to October by 2050. All GCMs agree on the occurrence of an increase in mean temperature to the order of 20% or even 30% viz 4.02 °C by 2100. the cashew nuts yields obtained on the last ten cropping season show a regressive trend in Centre, South and North -West with a regression rate ranging from 1.33% to 9.14%, while it exhibits an increasing trend in North –east with a growth rate of 0.11%. The rainfall have not influence the annual nuts production in Southern zone but the mean temperature of August and ETP of April have negative influence. The R square varies from 64% to 92%. From these results we can conclude that, rainfall from August to September (except South region), mean temperature and ETP are the main factors that determine cashew productivity (P<0.01 to P<0.001). The implementation of adaptation strategies is essential.