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Estimating Corn Emergence With Growing Degree Days: Data from May 7, 2021

Written collaboratively by Adam Varenhorst, Philip Rozeboom, Patrick Wagner, Sara Bauder, Jonathan Kleinjan, Ruben Behnke and Nathan Edwards.

Originally Submitted: May 13, 2021

With corn planting well underway in South Dakota, the next step is monitoring its emergence. One of the factors that can speed up or delay corn emergence is air temperature. On average, corn requires approximately 90–120 growing degree days (GDDs) to emerge. However, field conditions and planting date can change the number of GDDs required (Table 1).

Growing Degree Day Adjustments

Table 1. GDD adjustments caused by certain field conditions and specific factors.

Field Conditions Specific Factor Growing Degree Day (GDD) Adjustment Source
Soil Texture Fine Add 30–60 GDD Swan et al. 1987
  Course Subtract 30–60 GDD Swan et al. 1987
Residue % in-row residue cover Add 5 to 50 GDD Swan et al. 1987
Planting Date Before April Add 10–25 GDD Swan et al. 1987
  After May 15 Subtract 50–70 GDD Swan et al. 1987
Seed Zone Soil Moisture Below optimum Add 30 GDD Scheider and Gupta 1985
Seed Bed Condition Soil crusting or massive clods Add 30 GDD Scheider and Gupta 1985
Seeding Depth For each inch below two inches Add 15 GDD Hunter and Kannenberg 1972
Severe drought or heat stress Corn will not germinate until it absorbs 30% to 35% of its seed weight in water
-
Abendroth et al. 2011

*Table adapted from Elmore and Mueller. 2015. Growing degree units and corn emergence. University of Nebraska CropWatch.

Predicting Corn Emergence With Growing Degree Days

Corn growing degree days are calculated using the following equation:

(Maximum daily temperature + Minimum daily temperature) ÷ 2 - 50 degrees Fahrenheit

Color-coded drought monitor map of South Dakota. As of May 4, Northwest South Dakota is facing extreme drought, while the rest of the state is under abnormally dry to severe drought conditions. A Small portion of the northeast has adequate moisture.
Figure 1. U.S. Drought Monitor for South Dakota. Released Thursday, May 4, 2021. Courtesy: David Simeral, U.S. Drought Monitor

Corn growth and development occurs between 50 degrees Fahrenheit and 86 degrees Fahrenheit. If the minimum (low) or maximum (high) daily temperature exceeds these values in either direction, these base development temperatures should be substituted into the equation in place of the actual high or low daily temperature.

Table 2 contains current GDD estimates for several locations throughout South Dakota and uses the corn insurance date as a starting point. Ideally, the calculations would start on the date a field was planted. For this reason, these are general estimates. For most of South Dakota, enough growing degree days have been accumulated without consideration of field conditions for corn to be emerging. Emergence may be delayed in areas that are abnormally dry or experiencing extreme drought conditions (Figure 1).

    Table 2. Accumulated corn GDD in South Dakota.

    Location
    Accumulated Growing Degree Days
    (GDD) Since April 10, 2021
    Antelope
    104
    Baltic
    120
    Beresford
    160
    Bison
    100
    Britton
    99
    Brookings
    97
    Colton
    111
    Cottonwood
    121
    Dakota Lakes
    124
    Eagle Butte
    98
    Flandreau
    99
    Gettysburg
    91
    Groton
    91
    Hamill
    125
    Jewel Cave
    55
    Lemmon
    94
    McIntosh
    95
    McLaughlin
    91
    Mound City
    106
    Nisland
    98
    Oak Lake
    74
    Parkston
    145
    Redfield
    110
    Rosebud
    115
    Sioux Falls
    140
    South Shore
    81
    Sturgis
    98
    Volga
    99
    Webster
    69
    White Lake
    132

    *Data for calculating growing degree days was obtained
    from the South Dakota State University Mesonet.

    Sources:

    • Abendroth, L. J., R. W. Elmore, M. J. Boyer, and S. K. Marlay. 2011. Corn growth and development. Iowa State University.
    • Hunter, R. B. and L. W. Kannenberg. 1972. Effects of seed size on emergence, gain yield and plant in corn. Canadian Journal of Planting Science 52: 252-256.
    • Schneider, E. C. and S. C Gupta. 1985. Corn emergence as influenced by soil temperature, matric potential and aggregate size distribution. Journal Soil Science of America 49: 415-422.
    • Swan, J. B., E. C. Schneider, J. F. Moncrieg, W. H. Paulson, and A. E. Peterson. 1987. Estimating corn growth, yield, and grain moisture from air growing degree days and residue cover. Agronomy Journal 79: 53-60.