By: Stephanie Karhoff
Growing degree day (GDD) accumulation for the month of May rebounded after a week of above normal temperatures. In Williams County, 278 GDD were accumulated from May 1 to May 25, compared to 189 GDD in 2020. The 30-year average is 266 GDD. (Figure 1).
Figure 1. Comparison of Total GDD Accumulation from May 1 to May 25 in Williams County
It takes approximately 100-150 GDD for corn to emerge (VE) and at least an additional 246 GDD to reach the V3 growth stage (Ohio Agronomy Guide). As of May 23, 38% of corn was emerged in Ohio, compared to the 5-year average of 33% (USDA NASS). You can learn more about what is occurring in the corn plant from emergence to the V3 growth stage at: https://thekernel.info/corn-growth-stages-ve-to-v3whats-going-on/.
You can estimate corn emergence using the GDD calculator found at https://mrcc.illinois.edu/U2U/gdd/. To use the tool, find your location on the map and then select the “GDD Start” (a.k.a. actual/anticipated planting date). The graph will display accumulated GDD’s for your location.
References
National Agricultural Statistics Service (NASS), Crop Progress Report.
Thomison, P., Michel, A., Tilmon, K., Culman, S., and Paul, P. 2017. Chapter 4: Corn production. Bulletin 472 – Ohio Agronomy Guide, 15th Ed. Pages 32-55.