After a very cold April, May has been warmer-than-normal (Figure 1). This has meant that despite the slow start, corn planting is near average for this time of year (Figure 2). Producers may be interested in how that might influence corn development. Growing degree days (GDD) are the common method for tracking development. The new Degree Days page on the Kansas Mesonet is designed to provide flexibility for our users, including options to select the time period and more built-in calculations. Because of the flexibility, it is somewhat more complicated than the older version. An explanation of the features can be found in a previous eUpdate story from Issue 619.
For producers who planted early, the amount of GDD accumulation was limited. The graphs below show the GDD accumulation at Manhattan from April 1 – May 8 and from May 1 – May 8 (Figure 3).
The difference is even greater in northwest Kansas, where temperatures have been cooler. In Cheyenne County, temperatures averaged almost 2 degrees below normal. The growing degree accumulation is only 9 degree days above normal (Figure 4).
Warmer temperatures are expected in the next week, but when the high temperatures exceed the upper threshold of 86 degrees F (Figure 5), accumulation won’t be as rapid as with more moderate temperatures
If you have questions, please don’t hesitate to contact us.
Mary Knapp, Weather Data Library
Chip Redmond, Kansas Mesonet
Ignacio Ciampitti, Crop Production and Cropping Systems Specialist