Abstract

Cassava is Vietnam's third most important food source only after rice and sugarcane with an output of 10.673 thousand tonnes. However, farmers often irrigate little or dono irrigate on cassava and almost irrigation water comes from rainfall. The biggest challenge of the cassava industry in Vietnam is the lack of irrigation water due to the impact of climate variability. This work, therefore, evaluates the impact of weather conditions on cassava yield in the Son Hoa District, Phu Yen Province of Vietnam in the period 2010–15. The performance of the AquaCrop model is assessed comparing observed and simulated cassava yield. Results showed that simulated yields were consistent. Observed data during study period with R2 up to 0.88 and root mean square error (RMSE) equal to 0.24, respectively. The results indicated that cassava yield had a close correlation with rainfall and evapotranspiration factors. Cassava achieved high yield when high rainfall and low evapotranspiration were recorded at study area, while cassava yield obtained a low value when low rainfall and high evapotranspiration occurred. Based on the findings from this study showed that cassava yield in the study area was strongly dominated by the rainfall and evapotranspiration factors.