Effects of climate change and cultivar on summer maize phenology

To identify countermeasures to the effects of climate warming on crop production, we must understand the changes in crop phenology and the relationships between phenology and climate change and cultivar. We used summer maize phenological and climate data in the North China Plain, collected from 1981 to 2010. This study analyzed the spatiotemporal trends in phenological data and lengths of different growing phases, mean temperatures and rainfall. The analyses showed that sowing, jointing and anthesis occurred relatively early at 13 48.1%), 11 (40.7%) and 13 (48.1%) stations, respectively. Maturity dates were delayed significantly at 10 (37.0%) stations. The lengths of the vegetative growing phases, vegetative and reproductive growing phase at most stations showed a negative trend. The lengths of the reproductive growing phase increased at 25 (92.6%) stations, respectively. Furthermore, at most stations, the correlations between T means and lengths of the various growing phases were negative, whereas the correlations between rainfall and lengths of various growing phases were positive. Furthermore, a field experiment, including four summer maize cultivars which were introduced during the 1950s, 1970s, 1990s and 2000s, was carried out during 2012 to 2014. The analyses showed that the durations of the various growing phases increased significantly. These results indicated that climate warming accelerates summer maize growth and shortens the growing periods of maize growth, whereas cultivars shift might prolong the maize growing season. Therefore, the maize cultivars with more longer whole growing period should be adopt in the North China Plain under the trend of global warming and the adaptation strategy of maize production under climate change should include crop phenology in response to climate change. The findings presented here could guide the development of options to adapt maize production to climate change in the North China Plain and other areas with similar ecologies.