What will a cool, 2015 growing season mean for corn?

Heat is an important factor impacting crop development. Using a new, web-based tool, farmers can use their own numbers and compare 2015 to previous years.

Historical weather data has been collected and compiled for years, but it has not always been the easiest to apply to local questions. However, a web-based decision tool was recently developed that allows farmers to quickly compare current conditions to a 30-year historical perspective. Should your cropping strategy change, this tool makes it easy to project potential outcomes based on historical climate data. With the U2U Decision Support Tool – Corn GDD, users can change planting date and hybrid maturity to get an indication of what to expect this fall based on observed conditions during the past 30 years.

Given the variable rain patterns across Michigan in 2015, corn planting was delayed on some farms and right on time on other farms. Using the U2U Decision Support Tool, users can select the county, date of corn emergence and hybrid maturity. The program will pull in historic and current weather data, calculate actual and projected growing degree days (GDD) and provide a picture of how this year’s crop is progressing compared to previous years

Corn Outlook Graph 
Outlook for 101-day corn that emerged May 25.

Corn (101-day) that emerged May 25 in Clinton County had accumulated 939 GDD by July 4. In 2012, this same corn would have accumulated 1,081 GDD. The 30-year average for GDD on July 4 is 981. Last year, 2014, was also a cool year – this same corn would have been just 27 GDD ahead of this year. So, 2015 is below average and slightly below 2014 in GDD accumulation. The graph also predicts silking (red lines) and black layer (black lines) based on historic data.

Michigan State University Extension encourages producers to take this decision tool for a test drive. Using the U2U Decision Support Tool – Corn GDD, growers can run any number of scenarios to answer questions unique to their situation. Changing the inputs of planting date and corn maturity days are easy. While we realize no one can predict the future, we can look at history to determine probable risk, obtain some idea of the variability and range of outcomes and make decisions that we can live with.

The U2U Decision Support Tool – Corn GDD was developed by Useful to Useable (U2U), a team made up of faculty, staff and students from nine Midwestern universities working to develop decision support tools and resources to support resilient and profitable crop production. U2U is funded by a grant from the U.S. Department of Agriculture.

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