By Dennis Todey
Generally, planting season in South Dakota has progressed close to average without widespread delays. The Southeast part of the state has seen delays in many areas because of wet fields. There are also some social media reports of needs for replanting. As of Monday June 6 corn planted was 96%, which is close to last year and average. Emerged was at 85%, again close to last year and the 5 year average.
Corn Growing Degree Day Tool
Various tools exist to track crop progress. One of the best versions is from the USDA-AFRI sponsored project Useful to Usable. The U2U Corn GDD tool is specially developed for producers to track their corn progress based on existing temperatures information. The tool can be found under the Decision Tools section at the site above.
This tool updates daily provide current GDD conditions tailored to your location. Once you reach the site, choose your location to start the tool, which starts via default data. Then, the user can adjust planting date, season length of variety and a number of other choices. The result is a graph of current and projected GDD accumulation over the season.
Figure 1. Example graph from the corn growing degree day tool.
The above graph shows degree day accumulation based on a planting date of April 20 in Hanson County. Accumulated GDDs are compared to the smoothed 30 year average accumulation.
Management Applications
How can the tool be used? The simple first use is tracking current status where corn is compared to average.
In this delayed and possible replant season for people in Southeast South Dakota, the tool can also be used to make decisions. The current status shows when the crop is likely to reach black layer and be free of potential damage from a freeze. This can be used to determine potential for needing to purchase propane for drying or to change a marketing strategy if the corn is likely to lose yield or need additional drying.