Association between climate variability and teff yield: A case study of Horro Guduru Wallaga zone, northwestern Ethiopia

Climate change is one of the primary challenges that crop production is facing, with effects varying among different crops and regions. This study aimed to examine the associations of mean and extreme climate conditions with teff yield in the Horro Guduru Wallaga zone. Data on daily minimum and maximum temperatures and rainfall were collected from the Ethiopian Meteorological Institute (EMI) for the period 1981–2020, while teff production data from 2006 to 2020 were obtained from the Ethiopian Statistical Service (ESS). The primary inferential analysis was conducted using a multiple regression model consisting of only three mean climate variables. Due to multicollinearity, all extreme climate indices and rainy season characteristics such as rainfall onset, cessation, and length of the growing period (LGP) were excluded from the regression model and analyzed using Pearson correlation. All extreme temperature indices, except cool days (TX10p) and Min Tmin (TNn), indicated negative correlations with teff yield. The correlations were statistically significant only for warm days (TX90p) and Max Tmax (TXx). Teff yield also showed statistically insignificant negative correlations with rainfall onset and cessation, and an insignificant positive correlation with LGP. Additionally, the maximum 5-day precipitation amount (Rx5day) and maximum 1-day precipitation amount (Rx1day) showed positive and negative correlations with teff yield, respectively, though these relationships were statistically insignificant. Moreover, in the regression model, mean maximum temperature, mean minimum temperature, and total rainfall during the teff growing season showed negative associations with teff yield, with the relationship being statistically significant for mean maximum temperature. Generally, the three mean climate variables in the regression model accounted for approximately 31% of the interannual variability in teff yield, indicating that non-climatic factors may play important roles. To mitigate the negative effects of climate change on teff production, adjusting the sowing calendar and using adaptable teff varieties are suggested.