Climate change, weather variability and associated impact on arecanut and cocoa in humid tropics of India

This paper focuses on the weather variability and its influence on the yielding patterns of arecanut and cocoa over the past 43 years (1970–2012) at Vittal, Karnataka, which is located between 12^o 15’N latitude and 75^o 25’E longitude in humid tropics of India. After 2000, sudden changes in climate were noticed with increase in maximum and minimum temperatures, and RH_forenoon and the decrease in total rainfall, sunshine hours and evaporation. The trends of temperature increase are +0.4°C for mean maximum (P <0.001) and +0.4°C for mean minimum during the last decade. The observed difference between maximum and minimum is +0.8°C for the 43 year period. The on-station studies indicated that the yield variability in different years was 32% in arecanut and 38% in cocoa that explains the influence of climate on yield. The correlations and regressions between yield and weather parameters indicate differential response of arecanut and cocoa. The results indicate that the cocoa was more affected by climate variability than arecanut due to conspicuous changes in phenology and increased incidence of pests and diseases. The adaptation options available to farmers in changing climate scenario are also discussed.