Multi-Site Evaluation of Accumulated Temperature and Rainfall for Maize Yield and Disease in Loess Plateau

The Guanzhong region is a typical and important grain-producing area in China. The effect of accumulated temperature and rainfall on maize production is important in the face of global warming. Here, we collected meteorological data from six test sites in the Guanzhong region to study climate change from 1972 to 2018 in this area. A two-year study was conducted at multiple experimental sites to analyze the effect of climatic factors on maize yield and disease in the Guanzhong region. In the past 40 years, average temperatures have significantly increased at all sites, except for Hancheng. Rainfall varied significantly between years at each site, except for Huxian, with an overall declining trend. Accumulated temperature had a significant positive effect on yield (R2 = 0.28, p = 0.041 < 0.05), but rainfall did not affect yield (R2 = 0.0971, p = 0.324 > 0.05). During the growing period, total rainfall had a significant positive correlation with northern leaf blight disease in maize, and rainfall before silking had a significant positive correlation with ear length and row grain number. The demand for accumulated temperature by maize differed between sites. It is predicted that maize yield will increase with increasing temperature in the Guanzhong region. Greater attention should be paid to improve agronomic practices, such as adjustment of sowing dates, straw mulching, deep tillage, and pest control to adapt to future climate change.