Abstract: This study investigated the influence of climate change on the buckwheat growth period and yield in semi-arid regions of the Loess Plateau based on observations buckwheat localization experiments and data of climate factors. The results showed that the temperatures decreased significantly, with a climatic tendency rate of −0.81℃·10y⁻¹(P<0.01), and the precipitation increased significantly, with a climatic tendency rate of 48.55mm·10y⁻¹(P<0.01), while the sunshine duration increased significantly, with a climatic tendency rate of 4.76h·10y⁻¹(P<0.01) in tartary buckwheat whole growth period during 2009−2019. The temperatures decreased significantly, with a climatic tendency rate of −0.82℃·10y⁻¹(P<0.01), and the precipitation increased significantly, with a climatic tendency rate of 33.33mm·10y⁻¹(P<0.01), while the sunshine duration decreased significantly, with a climatic tendency rate of −28.98h·10y⁻¹(P<0.01) in common buckwheat whole growth period. The growth days of common and tartary buckwheat were shortened, with climatic tendency rate of 0.53d·y⁻¹ and 0.84d·y⁻¹ (P<0.01), respectively. The length of vegetative growth period of both common and tartary buckwheat decreased with increasing temperature and sunshine hours, and increased with increasing precipitation. The length of reproductive growth periods increased with the increase of temperature and sunshine hours, and decreased with the increase of precipitation. The tartary buckwheat yieldhas increased. Yield was highly significantly negatively correlated (P<0.01) with both temperature and sunshine hours of tartary buckwheat whole growth period. Yield was significantly positively correlated (P<0.01) with precipitation of tartary buckwheat whole growth period. Temperature was a key factor to affect tartary buckwheat yield. The common buckwheat yield has decreased. Yield was significantly positively correlated (P<0.05) with temperature, precipitation and sunshine hours of common buckwheat whole growth period. Temperature and sunshine hours during the whole growth period were key factors affecting common buckwheat yield.

Key words: Climate change, Buckwheat, Growth period, Yield, Loess Plateau