High Night Temperature Effects on Corn Yield

Many agronomists and growers involved in corn production are aware of the idea that above-average night temperatures during pollination and grain fill can reduce corn grain yield. This concept is almost a “central dogma” in corn production. 

A summary review of the weather and corn grain yield data for 2009 and 2010 is just one of many examples that support this statement. In 2009, many farmers in the Midwestern United States produced record corn grain yields. However, in 2010, even with adequate rainfall, corn grain yields were much lower. A notable difference between these two growing seasons was night temperatures following pollination; in the states of Nebraska, Kansas, Iowa, Missouri, and Illinois, the average minimum night temperatures during July and August of 2009 were about 5 to 8 ºF lower than the average minimum night temperatures in 2010 (Figures 1 and 2). Above-average night temperatures during pollination and grain fill can reduce corn grain yield. Despite general awareness among corn producers that high night temperatures can be detrimental to yield, the effects on specific plant processes and yield components are not as well understood.  

Learn more in the Crop Bulletin:  High Night Temperatures Effects on Corn Yield.