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Contributor

How much corn yield can you lose if you have high nighttime temps during grain fill?

I thought the board might be interested in a little research report I put together. Due to the difficulty of creating a field experiment to study the issue, there are no academic studies that I am aware of that quantify the impact of high nighttime temperatures during grain fill on corn yield. There is a lot of anecdotal evidence and theoretical predictions about yields being negatively impacted by warm nights during grain fill, but no quantitative studies. 

Using historical weather data and historical state-level yield and crop development data from NASS, I plotted the historical relationship between high nighttime temperatures during grain fill and end of season yields (detrended). Data studied was for Illinois and Indiana for the years 1992 through 2011. 

Results show that over the past 20 years, growers in Illinois have seen corn yields decrease by 3.6 bushels/acre for every degree of increase in average nighttime temperatures during grain fill and Indiana growers have seen yields decrease by 2.0 bushels/acre for every degree of increase in average nighttime temperatures during grain fill. 

The full study can be accessed at the link below and I'd be happy to discuss the results with anyone that has any questions! 

http://www.climate.com/2012outlook/nighttime-heat-stress