Trends in Observed Temperature and Rainfall Variability in Major Potato Growing Districts of Eastern Ethiopia

Abstract

Potato (Solanum tuberosum L.) is a major cash crop in the eastern highlands of Ethiopia owing to the cooler and moist climate in the region. Climate  variability threatens potato production since variations in rainfall patterns and temperature lead to severe moisture as well as other abiotic  and biotic stresses for the crop. Therefore, we conducted a study to analyze trends in the variability of rainfall and temperature in three major  potato growing districts (Woredas) in eastern Ethiopia, namely, Haramaya, Chiro, and Kombolcha. We acquired 38-year (1980–2017) historical and  observed meteorological data from the National Meteorology Agency of Ethiopia. Trends of rainfall and temperature were analyzed using the Man-  Kendall test. Rainfall variability analysis was done using the Precipitation Concentration Index (PCI), Standard Anomaly Index (SAI), and coefficient of  variation (CV %). The results showed that, over the 38-year period, the annual amount of rainfall in Haramaya district varied by 17.8% while those  of Kombolcha and Chiro varied by 66.8% and 28.7%, respectively. Both annual and seasonal maximum temperatures in Haramaya district showed  significantly (P < 0.05) increasing trends whereas the maximum temperature in Chiro district showed a non-significantly increasing trend. The PCI  value of Kombolcha ranged from high to very high indicating high concentration of rainfall in few months. Comparatively, Haramaya and Chiro  districts experienced higher frequencies of drought than Kombolcha district. It is concluded that there was a significant increasing trend of  minimum temperature at Haramaya and Chiro districts, and a significant increasing trend of Kiremt rainfall at Haramaya district that could lead to  reduced potato yields and increased incidences of diseases. Therefore, options should be sought to tackle the variability in trends of temperature  and rainfall and sustain potato production and enhance farmers’ resilience to climate change.