A new online growing degree day tool can help estimate when your corn crop will reach critical growth stages. The tool, called Corn GDD DST (Decision Support Tool), is free to use and does not need a log in or password.
The Corn GDD DST uses historical climate data to show you the most likely spring and fall frost dates for your county. In addition to frost dates, the tool will show a graph that includes likely dates for silking and black layer for the current growing season. The temperature data at the heart of the online tool is updated every day, so you can see how the current year's accumulated GDD compare to past years. Using climatology and long-term averages, a forecast or estimate is shown on when the crop will reach these critical growth stages.
You have many options to select from, including your planting date, maturity, years you would like to use for comparison, and graph display options. The website runs quickly which allows you to compare many scenarios. This way, you can try out some options at any time during the growing season such as calculating an ideal maturity for replanting, or trying to determine the likelihood that your existing crop will reach maturity before fall frost.
For example, the graphic here shows the data for Brown County, SD as of May 27. The vertical blue lines indicate historical spring and fall frost dates. The taller lines have been more common than the shorter lines. The shaded areas show the historical range of GDD during the growing season. The dark green line is the current season's accumulated GDD since May 1, and the dotted line uses the historical average accumulations to estimate when the crop will reach silk and black layer given a 95 day maturity.
Source : SDSU